Pablo Escobar, Drug Lord

In 1989, Forbes magazine listed Pablo cultivating a Robin Hood image and
Escobar as the seventh richest man in the distributing money to the poor.
world. Escobar began his climb to wealth In 1991, hoping to avoid extradition to
as a teenage car thief in the streets of the United States, Escobar turned himself
Medellin, Colombia, and eventually moved in to the Colombian government and
into the cocaine-smuggling business. At agreed to be sent to prison. However, the
the peak of his power in the mid-1980s, he prison compound could easily be mistaken
was shipping as much as eleven tons of for a country club. There he continued his
cocaine per flight in jetliners to the United high-flying lifestyle, trafficking by
States. Law enforcement officials estimate telephone and even murdering a few
that the Medellin cartel controlled 80 associates. When the Colombian
percent of the world’s cocaine market and government attempted to move Escobar to
was taking in about $25 billion annually. another jail, he escaped, again fearing
Escobar ruthlessly ruled by the gun: extradition to the United States.
murdering, assassinating, and Pressured by the U.S. government,
kidnapping. He was responsible for Colombia organized a task force dedicated
killing three presidential candidates in to apprehending Escobar. The manhunt
Colombia, as well as the storming of the for Escobar ended on December 2, 1993,
Colombian Supreme Court, which when he was cornered on the roof of one
resulted in the murder of half the justices. of his hideouts. A shootout ensued and
All the while, Escobar curried favor with Escobar was fatally wounded by a bullet
the Colombian general public by behind his ear.
Key Terms
anabolic steroids
analgesic
chromatography
confirmation
depressant
fluoresce
hallucinogen
infrared
ion
microcrystalline test
monochromatic light
monochromator
narcotic
physical dependence
psychological dependence
screening test
spectrophotometry
stimulant
ultraviolet
150 C H A P T E R 5

Learning Objectives
After studying this chapter you should be able to:
■ Compare and contrast psychological and physical ■ Describe the utility of ultraviolet and infrared
dependence spectroscopy for the identification of organic
compounds
■ Name and classify the commonly abused drugs
■ Describe the concept and utility of mass spectrometry
■ Describe the laboratory tests normally used to perform
for identification analysis
a routine drug identification analysis
■ Understand the proper collection and preservation of
■ Describe and explain the process of chromatography
drug evidence
■ Explain the difference between thin-layer
chromatography and gas chromatography

A drug can be defined as a natural or synthetic substance that is used to

produce physiological or psychological effects in humans or other animals.
However, criminalists are concerned primarily with a small number of
drugs—many of them illicit—that are commonly used for their intoxicating
effects. These include marijuana, the most widely used illicit drug in the
United States, and alcohol, which is consumed regularly by 90 million
Americans. Drug abuse has grown from a problem generally associated
with members of the lower end of the socioeconomic ladder to one that
cuts across all social and ethnic classes of society. Today, approximately
23 million people in the United States use illicit drugs.
Because of the epidemic proportions of illegal drug use, more than
75 percent of the evidence evaluated by crime laboratories in the United
States is drug related (see Figure 5–1). The deluge of drug specimens has
forced the expansion of existing crime laboratories and the creation of new
ones. For many concerned forensic scientists,the crime laboratory’s pre-
occupation with drug evidence represents a serious distraction from time
that could be devoted to evaluating evidence related to homicides
and other types of serious crimes. However, the increasing caseloads
associated with drug evidence have justified the expansion of forensic lab-
oratory services. This expansion has increased the overall analytical
capabilities of crime laboratories.

Drug Dependence
In assessing the potential danger of drugs, society has become particu-
larly conscious of their effects on human behavior. In fact, the first
drugs to be regulated by law in the early years of the twentieth century
were those deemed to have “habit-forming” properties. The early laws
were aimed primarily at controlling opium and its derivatives, cocaine,
and later marijuana. The ability of a drug to induce dependence after
repeated use is submerged in a complex array of physiological and social
factors.
Dependence on drugs exists in numerous patterns and in all degrees
of intensity, depending on the nature of the drug, the route of adminis-
tration, the dose, the frequency of administration, and the individual’s
rate of metabolism. Furthermore, nondrug factors play an equally
 Drugs 151

FIGURE 5–1 Drug bust.

Courtesy Syracuse
Newspapers/The Image Works

crucial role in determining the behavioral patterns associated with drug

use. The personal characteristics of the user, his or her expectations
about the drug experience, society’s attitudes and possible responses,
and the setting in which the drug is used are all major determinants of
drug dependence.
The question of how to define and measure a drug’s influence on the in-
dividual and its danger to society is difficult to assess. The nature and sig-
nificance of drug dependence must be considered from two overlapping
points of view: the interaction of the drug with the individual, and the drug’s
impact on society. It will be useful to approach the problem from two dis-
tinctly different aspects of human behavior—psychological dependence psychological
and physical dependence. dependence
The conditioned use of a drug
Psychological Dependence caused by underlying
The common denominator that characterizes all types of repeated drug use emotional needs.
is the creation of a psychological dependence for continued use of the physical dependence
drug. It is important to discard the unrealistic image that all drug users are Physiological need for a drug
hopeless “addicts” who are social dropouts. Most users present quite a brought about by its regular
normal appearance and remain both socially and economically integrated use and characterized by
in the life of the community. withdrawal sickness when
The reasons why some people abstain from drugs while others administration of the drug is
become moderately or heavily involved are difficult if not impossible to abruptly stopped.
152 C H A P T E R 5

delineate. Psychological needs arise from numerous personal and social

factors that inevitably stem from the individual’s desire to create a sense
of well-being and to escape from reality. In some cases, the individual may
seek relief from personal problems or stressful situations, or may be try-
ing to sustain a physical and emotional state that permits an improved
level of performance. Whatever the reasons, the underlying psychological
needs and the desire to fulfill them create a conditioned pattern of drug
abuse (see Figure 5–2).
The intensity of the psychological dependence associated with a drug’s
use is difficult to define and largely, depends on the nature of the drug
used. For drugs such as alcohol, heroin, amphetamines, barbiturates, and
cocaine, continued use will likely result in a high degree of involvement.
Other drugs, such as marijuana and codeine, appear to have a consider-
ably lower potential for the development of psychological dependence.
However, this does not imply that repeated abuse of drugs deemed to have
a low potential for psychological dependence is safe or will always produce
low psychological dependence. We have no precise way to measure or pre-
dict the impact of drug abuse on the individual. Even if a system could be
devised for controlling the many possible variables affecting a user’s
response, the unpredictability of the human personality would still have to
be considered.
Our general knowledge of alcohol consumption should warn us of the
fallacy of generalizing when attempting to describe the danger of drug
abuse. Obviously, not all alcohol drinkers are psychologically addicted to
the drug; most are “social” drinkers who drink in reasonable amounts
and on an irregular basis. Many people have progressed beyond this
stage and consider alcohol a necessary crutch for dealing with life’s
stresses and anxieties. However, a wide range of behavioral patterns exists

FIGURE 5–2 Young people

drinking. Courtesy Daytona
Beach News-Journal/Jim Tiller
 Drugs 153

among alcohol abusers, and to a large extent the determination of the

degree of psychological dependence must be made on an individual ba-
sis. Likewise, it would be fallacious to generalize that all users of mari-
juana can at worst develop a low degree of dependence on the drug. A
wide range of factors also influence marijuana’s effect, and heavy users
of the drug expose themselves to the danger of developing a high degree
of psychological dependence.

Physical Dependence
Although emotional well-being is the primary motive leading to repeated
and intensive use of a drug, certain drugs, taken in sufficient dose and fre-
quency, can produce physiological changes that encourage their contin-
ued use. Once the user abstains from such a drug, severe physical illness
follows. The desire to avoid this withdrawal sickness, or abstinence syn-
drome, ultimately causes physical dependence, or addiction. Hence, for the
addict who is accustomed to receiving large doses of heroin, the thought
of abstaining and encountering body chills, vomiting, stomach cramps,
convulsions, insomnia, pain, and hallucinations is a powerful inducement
for continued drug use.
Interestingly, some of the more widely abused drugs have little or no po-
tential for creating physical dependence. Drugs such as marijuana, LSD, and
cocaine create strong anxieties when their repeated use is discontinued;
however, no medical evidence attributes these discomforts to physiological
reactions that accompany withdrawal sickness. On the other hand, use of
alcohol, heroin, and barbiturates can result in development of physical
dependence.
Physical dependence develops only when the drug user adheres to a
regular schedule of drug intake; that is, the interval between doses must
be short enough so that the effects of the drug never wear off completely.
For example, the interval between injections of heroin for the drug
addict probably does not exceed six to eight hours. Beyond this time
the addict begins to experience the uncomfortable symptoms of with-
drawal. Many users of heroin avoid taking the drug on a regular basis
for fear of becoming physically addicted to its use. Similarly, the risk of
developing physical dependence on alcohol becomes greatest when the
consumption is characterized by a continuing pattern of daily use in
large quantities.
Table 5–1 categorizes some of the more commonly abused drugs ac-
cording to their effect on the body and summarizes their tendency to pro-
duce psychological dependence and to induce physical dependence with
repeated use.

Societal Aspects of Drug Use

The social impact of drug dependence is directly related to the extent to
which the user has become preoccupied with the drug. Here, the most im-
portant element is the extent to which drug use has become interwoven in
the fabric of the user’s life. The more frequently the drug satisfies the per-
son’s need, the greater the likelihood that he or she will become preoccu-
pied with its use, with a consequent neglect of individual and social
responsibilities. Personal health, economic relationships, and family oblig-
ations may all suffer as the drug-seeking behavior increases in frequency
and intensity and dominates the individual’s life. The extreme of drug
154 C H A P T E R 5

Table 5–1 The Potential of Some Commonly Abused Drugs

to Produce Dependence with Regular Use
Psychological Physical
Drug Dependence Dependence
Narcotics
Morphine High Yes
Heroin High Yes
Methadone High Yes
Codeine Low Yes

Depressants
Barbiturates (short-acting) High Yes
Barbiturates (long-acting) Low Yes
Alcohol High Yes
Methaqualone (Quaalude) High Yes
Meprobamate (Miltown, Equanil) Moderate Yes
Diazepam (Valium) Moderate Yes
Chlordiazepoxide (Librium) Moderate Yes
Stimulants
Amphetamines High ?
Cocaine High No
Caffeine Low No
Nicotine High Yes

Hallucinogens
Marijuana Low No
LSD Low No
Phencyclidine (PCP) High No

dependence may lead to behavior that has serious implications for the
public’s safety, health, and welfare.
Drug dependence in its broadest sense involves much of the world’s
population. As a result, a complex array of individual, social, cultural, legal,
and medical factors ultimately influence society’s decision to prohibit or
impose strict controls on a drug’s distribution and use. Invariably, society
must weigh the beneficial aspects of the drug against the ultimate
harm its abuse will do to the individual and to society as a whole. Obvi-
ously, many forms of drug dependence do not carry sufficient adverse so-
cial consequences to warrant their prohibition, as illustrated by the
widespread use of such drug-containing substances as tobacco and
coffee. Although the heavy and prolonged use of these drugs may even-
tually damage body organs and injure an individual’s health, there is no
evidence that they result in antisocial behavior, even with prolonged or
excessive use. Hence, society is willing to accept the widespread use of
these substances.
We are certainly all aware of the disastrous failure in the United States
to prohibit the use of alcohol during the 1920s and the current debate on
whether marijuana should be legalized. Each of these issues emphasizes
the delicate balance between individual desires and needs and society’s
concern with the consequences of drug abuse; moreover, this balance is
continuously subject to change and reevaluation.
 Drugs 155

Key Points
• A drug is a natural or synthetic substance that is used to produce phys-
iological or psychological effects in humans or other animals.

• Nondrug factors that play a part in drug dependence include the per-
sonal characteristics of the user, his or her expectations about the drug
experience, society’s attitudes and possible responses, and the setting
in which the drug is used.

• Physical dependence is defined as the physiological need for a drug

that has been brought about by its regular use. Psychological depen-
dence is the conditioned use of a drug caused by underlying emotional
needs.

Types of Drugs
Narcotic Drugs
The term narcotic is derived from the Greek word narkotikos, meaning narcotic
numbness or deadening. Although pharmacologists classify narcotic A drug that induces sleep and
drugs as substances that relieve pain and produce sleep, the term narcotic depresses vital body functions
has become popularly associated with any drug that is socially unaccept- such as blood pressure, pulse
able. As a consequence of this incorrect usage, many drugs are improperly rate, and breathing rate.
called narcotics.
This confusion has produced legal definitions that differ from the phar-
macological actions of many drugs. For example, until the early 1970s,
most drug laws in the United States incorrectly designated marijuana as a
narcotic. Even today, federal law classifies cocaine as a narcotic drug, al-
though pharmacologically, cocaine is actually a powerful central nervous
system stimulant, possessing properties opposite those normally associ-
ated with the depressant effects of a narcotic.
Opiates Medical professionals apply the term opiate to most of the
drugs properly classified as narcotics. Opiates behave pharmacologi-
cally like morphine, a painkiller derived from opium—a gummy, milky
juice exuded through a cut made in the unripe pod of the Asian poppy
(Papaver somniferium). Although morphine is readily extracted from
opium, the most commonly used opium-based drug is heroin, which is
produced by reacting morphine with acetic anhydride or acetyl chloride
(see Figure 5–3). Heroin’s high solubility in water makes its street prepa-
ration for intravenous administration rather simple, for only by injection
are heroin’s effects felt almost instantaneously and with maximum
sensitivity. To prepare the drug for injection, the addict frequently dis-
solves it in a small quantity of water in a spoon. The process can be
speeded up by heating the spoon over a candle or several matches. The
solution is then drawn into a syringe or eyedropper for injection under
the skin (see Figure 5–4).
Heroin and other narcotic drugs are analgesics—that is, they relieve analgesic
pain by depressing the central nervous system. Besides being a powerful A substance that lessens or
analgesic, heroin produces a “high” that is accompanied by drowsiness eliminates pain.
and a deep sense of well-being. The effect is short, generally lasting only
three to four hours. Regular use of heroin—or any other narcotic drug—
invariably leads to physical dependence, with all its dire consequences.
156 C H A P T E R 5

FIGURE 5–3 The opium

poppy and its derivatives.
Shown are the poppy plant,
crude and smoking opium,
codeine, heroin, and
morphine. Courtesy Drug
Enforcement Administration,
Washington, D.C.

FIGURE 5–4 Heroin

paraphernalia. Courtesy Drug
Enforcement Administration,
Washington, D.C.

Codeine is also present in opium, but it is usually prepared synthetically

from morphine. It is commonly used as a cough suppressant in prescrip-
tion cough syrup. Codeine, only one-sixth as strong as morphine, is not an
attractive street drug for addicts.

Synthetic Opiates A number of narcotic drugs are not naturally derived

from opium. However, because they have similar physiological effects on the
body as the opium narcotics, they are also commonly referred to as opiates.
Methadone is perhaps the best known synthetic opiate. In the 1960s, sci-
entists discovered that a person who received periodic doses of methadone
would not get high if he or she then took heroin or morphine. Although
 Drugs 157

Closer Analysis
What’s in That Bag?
The content of a typical heroin bag is an the material. Traditionally, quinine has
excellent example of the uncertainty been the most common diluent of heroin.
attached to buying illicit drugs. For many Like heroin, it has a bitter taste and was
years into the 1960s and early 1970s, probably originally used to obscure the
the average bag contained 15 to 20 actual potency of a heroin preparation
percent heroin. Currently, the average from those who wished to taste-test the
purity of heroin obtained in the illicit U.S. material before buying it. Other diluents
market is approximately 35 percent. The commonly added to heroin are starch,
addict rarely knows or cares what lactose, procaine (Novocain), and
comprises the other 65 percent or so of mannitol.

methadone is pharmacologically related to heroin, its administration appears

to eliminate the addict’s desire for heroin, with minimal side effects. These
discoveries led to the establishment of controversial methadone maintenance
programs in which heroin addicts receive methadone to reduce or prevent
future heroin use. Physicians increasingly prescribe methadone for pain re-
lief. Unfortunately the wide availability of methadone for legitimate medical
purposes has recently led to greater quantities of the drug being diverted into
the illicit market.
In 1995, the U.S. Food and Drug Administration (FDA) approved for
use the pain-killing drug OxyContin. The active ingredient in OxyContin is
oxycodone, a synthetic closely related to morphine and heroin in its chem-
ical structure. OxyContin is an analgesic narcotic that has effects similar to
those of heroin. It is prescribed to a million patients for treatment of
chronic pain with doctors writing close to seven million OxyContin pre-
scriptions each year. The drug is compounded with a time-release formu-
lation that the manufacturer initially believed would reduce the risk of
abuse and addiction. This has not turned out to be the case. It is estimated
that close to a quarter of a million individuals abuse the drug.
Because it is a legal drug that is diverted from legitimate sources,
OxyContin is obtained very differently from illegal drugs. Pharmacy rob-
beries, forged prescriptions, and theft of the drug from patients with a
legitimate prescription are ways in which abusers access OxyContin. Some
abusers visit numerous doctors and receive prescriptions even though
their medical condition may not warrant it.

Hallucinogens
Hallucinogens are drugs that can cause marked alterations in normal hallucinogen
thought processes, perceptions, and moods. Perhaps the most popular and A substance that induces
controversial member of this class of drugs is marijuana. changes in normal thought
processes, perceptions, and
moods.
Marijuana Marijuana is the popular name of the plant Cannabis sativa, a
weed that grows wild under most climatic conditions. The Cannabis plant
contains a chemical known as tetrahydrocannabinol, or THC, which pro-
duces the psychoactive effects experienced by users. The THC content of
Cannabis varies in different parts of the plant. The greatest concentration is
usually found in a sticky resin produced by the plant, known as hashish.
158 C H A P T E R 5

FIGURE 5–5 Several rolled marijuana cigarettes lie on a pile of crushed dried marijuana
leaves next to a tobacco cigarette. Courtesy Drug Enforcement Administration, Washington, D.C.

Declining concentrations are typically found in the flowers and leaves, re-
spectively. Little THC is found in the stem, roots, or seeds of the plant. The
potency and resulting effect of the drug fluctuate, depending on the relative
proportion of these plant parts in the marijuana mixture consumed
by the user. The most common method of administration is by smoking
either the dried flowers and leaves, or various preparations of hashish (see
Figure 5–5). Marijuana is also occasionally taken orally, typically baked in
sweets such as brownies or cookies.
Any study of marijuana’s effect on humans must consider the potency
of the marijuana preparation. An interesting insight into the relationship
between dosage level and marijuana’s pharmacological effect was pre-
sented in the first report of the National Commission on Marijuana and
Drug Abuse:
At low, usual “social” doses the user may experience an increased
sense of well-being; initial restlessness and hilarity followed by a
dreamy, carefree state of relaxation; alteration of sensory percep-
tions including expansion of space and time; a more vivid sense of
touch, sight, smell, taste and sound; a feeling of hunger, especially
a craving for sweets; and subtle changes in thought formation and
expression. To an unknowing observer, an individual in this state
of consciousness would not appear noticeably different from his
normal state.
At higher, moderate doses these same reactions are intensified
but the changes in the individual would still be scarcely noticeable
to an observer. At very high doses, psychotomimetic phenomena
may be experienced. These include distortion of body image, loss
of personal identity, sensory and mental illusions, fantasies and
hallucinations.1
 Drugs 159

Closer Analysis
Marijuana and Hashish
Marijuana is a weed that grows wild under
most climatic conditions. The plant grows
to a height of 5 to 15 feet and is
characterized by an odd number of leaflets
on each leaf. Normally each leaf contains
five to nine leaflets, all with serrated or
saw-tooth edges.

The potency of marijuana depends on its

form. Marijuana in the form of loose
vegetation has an average THC content of
about 3–4.5 percent (see Figure 1). The
more potent sinsemilla form averages
about 6–12 percent in THC content.
Sinsemilla is made from the unfertilized
flowering tops of the female Cannabis
plants, acquired by removing all male
plants from the growing field at the first
sign of their appearance. Production of
sinsemilla requires a great deal of
attention and care, and the plant is
therefore cultivated on small plots.
FIGURE 2 Blocks of hashish in front of
leaves and flowering tops of the marijuana
plant. Courtesy James King-Holmes, Photo
Researchers, Inc.

Hashish preparations average about 2–8

percent THC. On the illicit drug market,
hashish usually appears in the form of
compressed vegetation containing a high
percentage of resin (see Figure 2). A
par ticularly potent form of hashish is
known as liquid hashish or hashish oil.
Hashish in this form is normally a
viscous substance, dark green with a
tarr y consistency. Liquid hashish is
produced by efficiently extracting the
THC-rich resin from the marijuana plant
with an appropriate solvent, such as
alcohol. Liquid hashish typically varies
between 8 and 22 percent in THC
content. Because of its extraordinar y
FIGURE 1 The marijuana leaf. Courtesy Drug potency, one drop of the material can
Enforcement Administration, Washington, D.C. produce a “high.”
160 C H A P T E R 5

Marijuana easily qualifies as the most widely used illicit drug in the
United States. For instance, more than 43 million Americans have tried
marijuana, according to the latest surveys, and almost half that number
may be regular users. In addition to its widespread illegal use, accumulat-
ing evidence suggests that marijuana has potential medical uses. Two
promising areas of research are marijuana’s reduction of excessive eye
pressure in glaucoma and the lessening of nausea caused by powerful an-
ticancer drugs. Marijuana may also be useful as a muscle relaxant.
No current evidence suggests that experimental or intermittent use
causes physical or psychological harm. Marijuana does not cause physical
dependence. However, the risk of harm lies instead in heavy, long-term
use, particularly of the more potent preparations. Heavy users can develop
a strong psychological dependence on the drug. Some effects of marijuana
use include increased heart rate, dry mouth, reddened eyes, impaired
motor skills and concentration, and frequently hunger and an increased
desire for sweets.

Other Hallucinogens A substantial number of other substances with

widely varying chemical compositions are also used recreationally because
of their hallucinogenic properties. These include both naturally occurring
substances such as mescaline and psilocybin and synthetically created
drugs including lysergic acid diethylamide (LSD) and phencyclidine (PCP).

Closer Analysis
A Brief History of Marijuana
Marijuana and its related products have many physicians who foresaw its
been in use legally and illegally for almost application for treating a wide range of
three thousand years. The first reference ailments. At this time, it also found some
to medical use of marijuana is in a use as a painkiller and mild sedative. In
pharmacy book written about 2737 B.C. by later years, these applications were either
the Chinese emperor Shen Nung, who forgotten or ignored.
recommended it for “female weakness,
Marijuana was first introduced into the
gout, rheumatism, malaria, beriberi,
United States around 1920. The weed was
constipation and absent-mindedness.” In
smuggled by Mexican laborers across the
China, at that time and even today, the
border into Texas. American soldiers also
marijuana or hemp plant was also a major
brought the plant in from the ports of
source of fiber for rope production.
Havana, Tampico, and Veracruz. Although
Marijuana’s mood-altering powers probably
its use was confined to a small segment of
did not receive wide attention until about
the population, its popularity quickly
1000 B.C., when it became an integral part
spread from the border and Gulf states
of Hindu culture in India. After A.D. 500,
into most major U.S. cities. By 1937, forty
marijuana began creeping westward, and
six states and the federal government had
references to it began to appear in Persian
laws prohibiting the use or possession of
and Arabian literature.
marijuana. Under most of these laws,
The plant was probably brought to Europe marijuana was subject to the same
by Napoleon’s soldiers when they returned rigorous penalties applicable to morphine,
from Egypt in the early nineteenth century. heroin, and cocaine and was often
In Europe, the drug excited the interest of erroneously designated a narcotic.
 Drugs 161

LSD is synthesized from lysergic acid, a substance derived from ergot,

which is a type of fungus that attacks certain grasses and grains. The drug
appears in a variety of forms—as a pill, added to a cube of sugar, or ab-
sorbed onto a small piece of paper—and is taken orally. Its hallucinogenic
effects were first described by the Swiss chemist Albert Hofmann after he
accidentally ingested some of the material in his laboratory in 1943. LSD
produces marked changes in mood, leading to laughing or crying at the
slightest provocation. Feelings of anxiety and tension almost always
accompany LSD use. LSD is very potent; as little as 25 micrograms is
enough to start vivid visual hallucinations that can last for about twelve
hours. Although physical dependence does not develop with continued
use, the individual user may be prone to flashbacks and psychotic reactions
even after use is discontinued.
Abuse of the hallucinogen phencyclidine, commonly called PCP, has re-
cently grown to alarming proportions. Because this drug can be synthe-
sized by simple chemical processes, it is manufactured surreptitiously for
the illicit market in so-called clandestine laboratories (see Figure 5–6).
These laboratories range from large, sophisticated operations to small labs
located in a garage or bathroom. Small-time operators normally have little
or no training in chemistry and employ “cookbook” methods to synthesize
the drug. Some of the more knowledgeable and experienced operators
have been able to achieve clandestine production levels that approach a
commercial level of operation.
Phencyclidine is often mixed with other drugs, such as LSD or am-
phetamine, and is sold as a powder (“angel dust”), capsule, or tablet, or as
a liquid sprayed on plant leaves. The drug is smoked, ingested, or sniffed.
Following oral intake of moderate doses (1–6 milligrams), the user first ex-
periences feelings of strength and invulnerability, along with a dreamy
sense of detachment. However, the user soon becomes unresponsive, con-
fused, and agitated. Depression, irritability, feelings of isolation, audio and

FIGURE 5–6 Scene from a clandestine drug laboratory. Courtesy Drug Enforcement
Administration, Washington, D.C.
162 C H A P T E R 5

visual hallucinations, and sometimes paranoia accompany PCP use. Severe

depression, tendencies toward violence, and suicide accompany long-term
daily use of the drug. In some cases, the PCP user experiences sudden
schizophrenic behavior days after the drug has been taken.

Depressants
Depressants are drugs that slow down, or depress, the central nervous sys-
tem. Several types of drugs fall under this category, including the most
widely used drug in the United States—alcohol.

Alcohol (Ethyl Alcohol) Many people overlook the fact that alcohol is a drug,
depressant however, it exerts a powerful depressant action on the central nervous
A substance that slows down, system. When alcohol enters the bloodstream, it quickly travels to the brain,
or depresses, the functions of where it suppresses the brain’s control of thought processes and muscle
the central nervous system. coordination. Low doses of alcohol tend to inhibit the mental processes
of judgment, memory, and concentration. The drinker’s personality be-
comes expansive, and he or she exudes confidence. When taken in moder-
ate doses, alcohol reduces coordination substantially, inhibits orderly
thought processes and speech patterns, and slows reaction times. Under
these conditions, the ability to walk or drive becomes noticeably impaired.
Higher doses of alcohol may cause the user to become highly irritable and
emotional; displays of anger and crying are not uncommon. Extremely high
doses may cause an individual to lapse into unconsciousness or even a
comatose state that may precede a fatal depression of circulatory and respi-
ratory functions. The behavioral patterns of alcohol intoxication vary and
depend partly on such factors as social setting, amount consumed, and the
personal expectation of the individual with regard to alcohol.
In the United States, the alcohol industry annually produces more than
one billion gallons of spirits, wine, and beer for which 90 million consumers

FIGURE 5–7 Rows of alcohol bottles behind a bar. Courtesy Jeremy Liebman/Stone/Getty
Images
 Drugs 163

pay nearly $40 billion. Unquestionably, these and other statistics support the
fact that alcohol is the most widely used and abused drug (see Figure 5–7).

Barbiturates Barbiturates are derivatives of barbituric acid, a substance

first synthesized by a German chemist, Adolf Von Bayer, more than a hun-
dred years ago. They are commonly referred to as “downers” because they
relax the user, create a feeling of well-being, and produce sleep. Like alco-
hol, barbiturates suppress the vital functions of the central nervous system.
Twenty-five barbiturate derivatives are currently used in medical practice
in the United States; however, five—amobarbital, secobarbital, phenobar-
bital, pentobarbital, and butabarbital—tend to be used for most medical
applications.
Normally, barbiturate users take these drugs orally. The average seda-
tive dose is about 10–70 milligrams. When taken in this fashion, the drug
enters the blood through the walls of the small intestine. Some barbiturates,
such as phenobarbital, are classified as long-acting barbiturates. They are
absorbed into the bloodstream more slowly than others and therefore
produce less pronounced effects than faster-acting barbiturates. The
slow action of phenobarbital accounts for its low incidence of abuse. Appar-
ently, barbiturate abusers prefer the faster-acting varieties—secobarbital,
pentobarbital, and amobarbital.
Since the early 1970s, a nonbarbiturate depressant, methaqualone
(Quaalude), has appeared on the illicit-drug scene. Methaqualone is a pow-
erful sedative and muscle relaxant that possesses many of the depressant
properties of barbiturates. When taken in prescribed amounts, barbitu-
rates are relatively safe, but in instances of extensive and prolonged use,
physical dependence can develop.

Antipsychotics and Antianxiety Drugs Although these drugs can be consid-

ered depressants, they differ from barbiturates in the extent of their actions
on the central nervous system. Generally, these drugs produce a relaxing
tranquility without impairing high-thinking faculties or inducing sleep.
Antipsychotics such as reserpine and chlorpromazine have been used to re-
duce the anxieties and tensions of mental patients. Antianxiety drugs are
commonly prescribed to deal with the everyday tensions of many healthy
people. These drugs include meprobamate (Miltown), chlordiazepoxide
(Librium), and diazepam (Valium).
In the past thirty five years, the use of these drugs—particularly
antianxiety drugs—has grown dramatically. Medical evidence shows that
these drugs produce psychological and physical dependence with re-
peated and high levels of usage. For this reason, the widespread prescrib-
ing of antianxiety drugs to overcome the pressures and tensions of life has
worried many who fear the creation of a legalized drug culture.

“Huffing” Since the early 1960s, “huffing,” the practice of sniffing materials
containing volatile solvents (airplane glue or model cement, for example),
has grown in popularity. Another dimension has recently been added to
the problem with the increasing number of incidents involving the sniffing
of aerosol gas propellants such as freon. All materials abused by huffing
contain volatile or gaseous substances that are primarily central nervous
system depressants. Although toluene (a solvent used in airplane glue)
seems to be the most popular solvent to sniff, others can produce compara-
ble physiological effects. These chemicals include naphtha, methyl ethyl
ketone (antifreeze), gasoline, and trichloroethylene (dry-cleaning solvent).
164 C H A P T E R 5

The usual immediate effects of huffing are a feeling of exhilaration and

euphoria combined with slurred speech, impaired judgment, and double vi-
sion. Finally, the user may experience drowsiness and stupor, with these de-
pressant effects slowly wearing off as the user returns to a normal state.
Most experts believe that users become physiologically dependent on the
effects achieved by huffing. However, little evidence suggests that solvent
inhalation is addictive. But huffers expose themselves to the danger of liver,
heart, and brain damage from the chemicals they have inhaled. Even worse,
sniffing of some solvents, particularly halogenated hydrocarbons such as
freon and related gases, is accompanied by a significant risk of death.

Stimulants
stimulant The term stimulants refers to a range of drugs that stimulate, or speed up,
A substance that speeds up, or the central nervous system.
stimulates, the central nervous
system. Amphetamines Amphetamines are a group of synthetic stimulants that
share a similar chemical structure and are commonly referred to in the ter-
minology of the drug culture as “uppers” or “speed.” They are typically
taken either orally or via intravenous injection, and provide a feeling of
well-being and increased alertness that is followed by a decrease in fatigue
and a loss of appetite. However, these apparent benefits of the drug are ac-
companied by restlessness and instability or apprehension, and once the
stimulant effect wears off, depression may set in.
In the United States, the most serious form of amphetamine abuse stems
from intravenous injection of amphetamine or its chemical derivative,
methamphetamine (see Figure 5–8). The desire for a more intense amphet-
amine experience is the primary motive for this route of administration. The
initial sensation of a “flash” or “rush,” followed by an intense feeling of plea-
sure, constitutes the principal appeal of the intravenous route for the user.
During a “speed binge,” the individual may inject amphetamines every two
to three hours. Users have reported experiencing a euphoria that produces
hyperactivity, with a feeling of clarity of vision as well as hallucinations.

FIGURE 5–8 Granular amphetamine

beside a razor blade. Courtesy Cordelia
Molloy, Photo Researchers, Inc.
 Drugs 165

As the effect of the amphetamines wears off, the individual lapses into a pe-
riod of exhaustion and may sleep continuously for one or two days. Fol-
lowing this, the user often experiences a prolonged period of severe
depression, lasting from days to weeks.
A smokable form of methamphetamine known as “ice” is reportedly in
heavy demand in some areas of the United States. Ice is prepared by slowly
evaporating a methamphetamine solution to produce large, crystal-clear
“rocks.” Like crack cocaine (discussed next), ice is smoked and produces ef-
fects similar to those of crack cocaine, but the effects last longer. Once the
effects of ice wear off, users often become depressed and may sleep for days.
Chronic users exhibit violent destructive behavior and acute psychosis
similar to paranoid schizophrenia. Repeated use of amphetamines leads to
a strong psychological dependence, which encourages their continued
administration.

Cocaine Between 1884 and 1887, pioneering psychologist Sigmund Freud

created something of a sensation in European medical circles by describing
his experiments with a new drug. He reported a substance of seemingly
limitless potential as a source of “exhilaration and lasting euphoria” that
permitted “intensive mental or physical work [to be] performed without fa-
tigue. . . . It is as though the need for food and sleep was completely banished.”
The object of Freud’s enthusiasm was cocaine, a stimulant extracted
from the leaves of Erythroxylon coca, a plant grown in the Andes mountains
of South America as well as in tropical Asia (see Figure 5–9). Most com-
monly, cocaine is sniffed or “snorted” and is absorbed into the body through
the mucous membranes of the nose, although it is sometimes injected.
Cocaine is a powerful stimulant to the central nervous system, and its effects
resemble those caused by amphetamines—namely, increased alertness and
vigor, accompanied by suppression of hunger, fatigue, and boredom.
Cocaine produces a feeling of euphoria by stimulating a pleasure center in
the base of the brain, in an area connected to nerves that are responsible for
emotions. It stimulates this pleasure center to a far greater degree than it

FIGURE 5–9 Coca leaves and illicit

forms of cocaine. Courtesy Drug
Enforcement Administration,
Washington, D.C.
166 C H A P T E R 5

would ever normally be stimulated. Some regular users of cocaine report

accompanying feelings of restlessness, irritability, and anxiety. Cocaine used
chronically or at high doses can have toxic effects. Cocaine-related deaths
result from cardiac arrest or seizures followed by respiratory arrest.
A particularly potent form of cocaine known as “crack” can be pro-
duced by mixing cocaine with baking soda and water and then heating the
resulting solution. This material is then dried and broken into tiny chunks
that dealers sell as crack “rocks” that are sufficiently volatile to be smoked.
The faster the cocaine level rises in the brain, the greater the euphoria, and
the surest way to obtain a fast rise in the brain’s cocaine level is to smoke
crack. Inhaling the cocaine vapor delivers the drug to the brain in less than
fifteen seconds—about as fast as injecting it and much faster than snorting
it. The dark side of crack, however, is that the euphoria fades quickly as co-
caine levels drop, leaving the user feeling depressed, anxious, and plea-
sureless. The desire to return to a euphoric feeling is so intense that crack
users quickly develop a habit for the drug that is almost impossible to over-
come. Only a small percentage of crack abusers will ever be cured of this
drug habit.
In the United States, cocaine abuse is on the rise. Many people are
apparently using cocaine to improve their ability to work and to keep
going when tired. While there is no evidence of physical dependency
accompanying cocaine’s repeated use, abstention from cocaine after
prolonged use brings on severe bouts of mental depression, which pro-
duce a very strong compulsion to resume using the drug. In fact, labo-
ratory experiments with animals have demonstrated that of all the
commonly abused drugs, cocaine produces the strongest psychological
compulsions for continued use.
The United States spends millions of dollars annually in attempting to
control cultivation of the coca leaf in various South American countries
and to prevent cocaine trafficking into the United States. Three-quarters of
the cocaine smuggled into the United States is refined in clandestine labo-
ratories in Colombia. The profits are astronomical. Peruvian farmers may
be paid $200 for enough coca leaves to make one pound of cocaine. The re-
fined cocaine is worth $1,000 when it leaves Colombia and sells at retail in
the United States for up to $20,000.

Club Drugs
The term club drugs refers to synthetic drugs that are often used at night-
clubs, bars, and raves (all-night dance parties). Substances that are used as
club drugs include, but are not limited to, MDMA (Ecstasy, see Figure 5–10),
GHB (gamma hydroxybutyrate), Rohypnol (“Roofies”), ketamine, and
methamphetamine. These drugs have become popular at the dance scene as
a way to stimulate the rave experience. A high incidence of use has been
found among teens and young adults.
GHB and Rohypnol are central nervous system depressants that are of-
ten connected with drug-facilitated sexual assault, rape, and robbery. Ef-
fects accompanying the use of GHB include dizziness, sedation, headache,
and nausea. Recreational users have reported euphoria, relaxation, disin-
hibition, and increased libido (sex drive). Rohypnol causes muscle relax-
ation, loss of consciousness, and an inability to remember what happened
during the hours after ingesting the drug. This is particularly a concern in
a sexual assault because victims are physically unable to resist the attack.
Unsuspecting victims become drowsy or dizzy. Effects are even stronger
when the drug is combined with alcohol because the user experiences
memory loss, blackouts, and disinhibition. Drugs such as Rohypnol and
 Drugs 167

FIGURE 5–10 Ecstasy, a popular club drug. Courtesy Rusty Kennedy, AP Wide World Photos

GHB are odorless, colorless, and tasteless, and thus remain undetected
when slipped into a drink.
Methylenedioxymethamphetamine, also known as MDMA or Ecstasy,
is a synthetic, mind-altering drug that exhibits many hallucinogenic and
amphetamine-like effects. Ecstasy was originally patented as an appetite
suppressant and was later discovered to induce feelings of happiness
and relaxation. Recreational drug users find that Ecstasy enhances self-
awareness and decreases inhibitions. However, seizures, muscle breakdown,
stroke, kidney failure, and cardiovascular system failure often accompany
chronic abuse of Ecstasy. In addition, chronic use of Ecstasy leads to serious
damage to the areas of the brain responsible for thought and memory.
Ecstasy increases heart rate and blood pressure; produces muscle tension,
teeth grinding, and nausea; and causes psychological difficulties such as
confusion, severe anxiety, and paranoia. The drug can cause significant in-
creases in body temperature from the combination of the drug’s stimulant
effect with the often hot, crowded atmosphere of a rave club.
Ketamine is primarily used in veterinary medicine as an animal anes-
thetic. When used by humans, the drug can cause euphoria and feelings of
unreality accompanied by visual hallucinations. Ketamine can also cause
impaired motor function, high blood pressure, amnesia, and mild respira-
tory depression.

Anabolic Steroids
Anabolic steroids are synthetic compounds that are chemically related to anabolic steroids
the male sex hormone testosterone. Testosterone has two different effects on Synthetic compounds
the body. It promotes the development of secondary male characteristics chemically related to the male
(androgenic effects), and it accelerates muscle growth (anabolic effects). Ef- sex hormone testosterone that
forts to promote muscle growth and to minimize the hormone’s androgenic are used to promote muscle
effects have led to the synthesis of numerous anabolic steroids. However, a growth.
steroid free of the accompanying harmful side effects of an androgen drug
has not yet been developed.
168 C H A P T E R 5

Incidence of steroid abuse first received widespread public attention

when both amateur and professional athletes were discovered using these
substances to enhance their performance. Interestingly, current research
on male athletes given anabolic steroids has generally found little or, at
best, marginal evidence of enhanced strength or performance. While the
full extent of anabolic steroid abuse by the general public is not fully
known, the U.S. government is sufficiently concerned to regulate the avail-
ability of these drugs to the general population and to severely punish in-
dividuals for illegal possession and distribution of anabolic steroids. In
1991, anabolic steroids were classified as controlled dangerous sub-
stances, and the Drug Enforcement Administration was given enforce-
ment power to prevent their illegal use and distribution.
Anabolic steroids are usually taken by individuals who are unfamiliar
with the harmful medical side effects. Liver cancer and other liver mal-
functions have been linked to steroid use. These drugs also cause mas-
culinizing effects in females, infertility, and diminished sex drive in males.
For teenagers, anabolic steroids result in premature halting of bone
growth. Anabolic steroids can also cause unpredictable effects on mood
and personality, leading to unprovoked acts of anger and destructive be-
havior. Depression is also a frequent side effect of anabolic steroid abuse.

Key Points
• Narcotic drugs are analgesics, meaning they relieve pain by depressing
the central nervous system.

• The most common source for narcotic drugs is opium. Morphine is ex-
tracted from opium and used to synthesize heroin.

• Opiates are not derived from opium or morphine, but they have the
same physiological effects on the body. Examples of opiates include
methadone and OxyContin (oxycodone).

• Hallucinogens cause marked changes in normal thought processes,

perceptions, and moods. Marijuana is the most well-known drug in this
class. Other hallucinogens include LSD, mescaline, PCP, psilocybin,
and MDMA (Ecstasy).

• Depressants decrease the activity of the central nervous system, calm

irritability and excitability, and produce sleep. Depressants include al-
cohol (ethanol), barbiturates, tranquilizers, and various substances that
can be sniffed, such as airplane glue or model cement.

• Stimulants increase the activity of the central nervous system and are
taken to increase alertness and activity. Stimulants include ampheta-
mines, sometimes known as “uppers” or “speed,” and cocaine, which
in its freebase form is known as crack.

• Club drugs are synthetic drugs that are used at nightclubs, bars, and
raves (all-night dance parties). Some club drugs act as stimulants; oth-
ers have depressant effects.

• Anabolic steroids are synthetic compounds that are chemically related to

the male sex hormone testosterone. Anabolic steroids are often abused
by individuals who are interested in accelerating muscle growth.
 Drugs 169

Drug-Control Laws
The provisions of drug laws are of particular interest to the criminalist, for
they may impose specific analytical requirements on drug analysis. For ex-
ample, the severity of a penalty associated with the manufacture, distribu-
tion, possession, and use of a drug may depend on the weight of the drug
or its concentration in a mixture. In such cases, the chemist’s report must
contain all information that is needed to properly charge a suspect under
the provisions of the existing law.
The provisions of any drug-control law are an outgrowth of national
and local law enforcement requirements and customs, as well as the result
of moral and political philosophies. These factors have produced a wide
spectrum of national and local drug-control laws. Although their detailed
discussion is beyond the intended scope of this book, a brief description of
the U.S. federal law known as the Controlled Substances Act will illustrate
a legal drug classification system that has been created to prevent and con-
trol drug abuse. Many states have modeled their own drug-control laws af-
ter this act, an important step in establishing uniform drug-control laws
throughout the United States.

Closer Analysis
Controlled Substances Act
The federal law establishes five schedules phencyclidine (PCP), most
of classification for controlled dangerous amphetamine preparations, and most
substances on the basis of a drug’s barbiturate preparations containing
potential for abuse, potential for physical amobarbital, secobarbital, and
and psychological dependence, and pentobarbital. Dronabinol, the synthetic
medical value. This classification system is equivalent of the active ingredient in
extremely flexible in that the U.S. attorney marijuana, has been placed in
general has the authority to add, delete, or schedule II in recognition of its growing
reschedule a drug as more information medical uses in treating glaucoma and
becomes available. chemotherapy patients.
Schedule III. Schedule III drugs have less
Schedule I. Schedule I drugs have a high
potential for abuse than those in
potential for abuse, have no currently
schedules I and II, a currently accepted
accepted medical use in the United
medical use in the United States, and
States, and/or lack accepted safety for
a potential for low or moderate physical
use in treatment under medical
dependence or high psychological
supervision. Drugs controlled under
dependence. Schedule III controls,
this schedule include heroin,
among other substances, all
marijuana, methaqualone, and LSD.
barbiturate preparations (except
Schedule II. Schedule II drugs have a high
phenobarbital) not covered under
potential for abuse, a currently
schedule II and certain codeine
accepted medical use or a medical use
preparations. Anabolic steroids were
with severe restrictions, and a potential
added to this schedule in 1991.
for severe psychological or physical
Schedule IV. Schedule IV drugs have a low
dependence. Schedule II drugs include
potential for abuse relative to schedule
opium and its derivatives not listed in
III drugs and have a current medical
schedule I, cocaine, methadone,
(continued )
170 C H A P T E R 5

Closer Analysis
Controlled Substances Act (continued )

Table 5–2 Control Mechanisms of the Controlled Substances Act

Record Manufacturing Distribution Dispensing
Schedule Registration Keeping Quotas Restrictions Limits

I Required Separate Yes Order forms Research use only

II Required Separate Yes Order forms Rx: written; no Refills
III Required Readily No, but some Records Rx: written or oral;
retrievable drugs limited by required with medical
schedule II quotas authorization refills up
to 5 times in 6 months
IV Required Readily No, but some Records Rx: written or oral; with
retrievable drugs limited by required medical authorization
schedule II quotas refills up to 5 times
in 6 months
V Required Readily No, but some Records Over-the-counter
retrievable drugs limited by required (Rx drugs limited to
schedule II quotas MD’s order) refills up
to 5 times

Source: Drug Enforcement Administration, Washington, D.C.

use in the United States; their abuse related to the schedules as well. The most
may lead to limited dependence severe penalties are associated with drugs
relative to schedule III drugs. Drugs listed in schedules I and II. For example, for
controlled in this schedule include drugs included in schedules I and II, a first
propoxyphene (Darvon), phenobarbital, offense is punishable by up to twenty years
and tranquilizers such as meprobamate in prison and/or a fine of up to $1 million
(Miltown), diazepam (Valium), and for an individual or up to $5 million for other
chlordiazepoxide (Librium). than individuals. Table 5–2 summarizes the
Schedule V. Schedule V drugs must show control mechanisms and penalties for each
low abuse potential, have medical use in schedule of the Controlled Substances Act.
the United States, and have less
potential for producing dependence than The Controlled Substances Act also
schedule IV drugs. Schedule V controls stipulates that an offense involving a
certain opiate drug mixtures that contain controlled substance analog, a chemical
nonnarcotic medicinal ingredients. substance substantially similar in
chemical structure to a controlled
Controlled dangerous substances listed in
substance, triggers penalties as if it were
schedules I and II are subject to
a controlled substance listed in
manufacturing quotas set by the attorney
schedule I. This section is designed to
general. For example, eight billion doses
combat the proliferation of so-called
of amphetamines were manufactured in the
designer drugs—substances that are
United States in 1971. In 1972, production
chemically related to some controlled
quotas were established reducing
drugs and are pharmacologically very
amphetamine production approximately 80
potent. These substances are
percent below 1971 levels.
manufactured by skilled individuals in
The criminal penalties for unauthorized clandestine laboratories, with the
manufacture, sale, or possession of knowledge that their products will not be
controlled dangerous substances are covered by the schedules of the Controlled
 Drugs 171

Import–Export Manufacturer/Distributor Reports Criminal Penalties for Individual

Narcotic Nonnarcotic Security to Drug Enforcement Administration Trafficking (First Offense)

Permit Permit Vault/safe Yes 0–20 years/$1 million

Permit Permit Vault/safe Yes 0–20 years/$1 million
Permit Declaration Secure Yes, narcotic 0–5 years/$250,000
storage area No, nonnarcotic

Permit Declaration Secure Manufacturer only, 0–3 years/$250,000

storage area narcotic
No, nonnarcotic

Permit Declaration Secure Manufacturer only, 0–1 year/$100,000

to import; storage area narcotic
declaration No, nonnarcotic
to export

Substances Act. For instance, fentanyl is a designed to manufacture controlled

power ful narcotic that is commercially substances. The act regulates the
marketed for medical use and is also manufacture and distribution of precursors,
listed as a controlled dangerous the chemical compounds used by
substance. This drug is about one clandestine drug laboratories to synthesize
hundred times as potent as morphine. abused drugs. Targeted precursor
A number of substances chemically chemicals are listed in the definition
related to fentanyl have been synthesized section of the Controlled Substances Act.
by underground chemists and sold on the Severe penalties are provided for a person
street. The first such substance who possesses a listed precursor chemical
encountered was sold under the street with the intent to manufacture a controlled
name China White. These drugs have substance or who possesses or distributes
been responsible for more than a hundred a listed chemical knowing, or having
overdose deaths in California and nearly reasonable cause to believe, that the listed
twenty deaths in western Pennsylvania. As chemical will be used to manufacture a
designer drugs, such as China White, are controlled substance. In addition,
identified and linked to drug abuse, they precursors to PCP, amphetamines, and
are placed in appropriate schedules. methamphetamines are enumerated
specifically in schedule II, making them
The Controlled Substances Act also
subject to regulation in the same manner
reflects an effort to decrease the
as other schedule II substances.
prevalence of clandestine drug laboratories

Key Points
• Federal law establishes five schedules of classification for controlled
dangerous substances on the basis of a drug’s potential for abuse, po-
tential for physical and psychological dependence, and medical value.
172 C H A P T E R 5

Forensic Drug Analysis

One only has to look into the evidence vaults of crime laboratories to
appreciate the assortment of drug specimens that confront the criminalist.
The presence of a huge array of powders, tablets, capsules, vegetable
matter, liquids, pipes, cigarettes, cookers, and syringes is testimony to the
vitality and sophistication of the illicit-drug market. If outward appearance
is not evidence enough of the difficult analytical chore facing the forensic
chemist, consider the complexity of the drug preparations themselves.
Usually these contain active drug ingredients of unknown origin and iden-
tity, as well as additives—for example, sugar, starch, and quinine—that di-
lute their potency and stretch their value on the illicit-drug market. Do not
forget that illicit-drug dealers are not hampered by government regula-
tions that ensure the quality and consistency of a product.
When a forensic chemist picks up a drug specimen for analysis, he or
she can expect to find just about anything, so all contingencies must be
prepared for. The analysis must leave no room for error, because its results
will have a direct bearing on the process of determining the guilt or inno-
cence of a defendant. There is no middle ground in drug identification—
either the specimen is a specific drug or it is not—and once a positive
conclusion is drawn, the chemist must be prepared to support and defend
the validity of the results in a court of law.

Screening and Confirmation

The challenge or difficulty of forensic drug identification comes in se-
lecting analytical procedures that will ensure a specific identification of a
drug. Presented with a substance of unknown origin and composition,
the forensic chemist must develop a plan of action that will ultimately
yield the drug’s identity. This plan, or scheme of analysis, is divided into
two phases.
First, faced with the prospect that the unknown substance may be any
one of a thousand or more commonly encountered drugs, the analyst must
screening test employ screening tests to reduce these possibilities to a small and man-
A preliminary test used to ageable number. This objective is often accomplished by subjecting the ma-
reduce the number of possible terial to a series of color tests that produce characteristic colors for the
identities of an unknown more commonly encountered illicit drugs. Even if these tests produce neg-
substance. ative results, their value lies in having excluded certain drugs from further
consideration.
Once the number of possibilities has been reduced substantially, the
second phase of the analysis must be devoted to pinpointing and confirm-
ing the drug’s identity. In an era in which crime laboratories receive volu-
minous quantities of drug evidence, it is impractical to subject a drug to all
the chemical and instrumental tests available. Indeed, it is more realistic to
look on these techniques as constituting a large analytical arsenal. The
chemist, aided by training and experience, must choose tests that will most
conveniently identify a particular drug.
Forensic chemists often use a specific test to identify a drug substance
to the exclusion of all other known chemical substances. A single test that
confirmation identifies a substance is known as a confirmation. The analytical scheme
A single test that specifically sometimes consists of a series of nonspecific or presumptive tests. Each
identifies a substance. test in itself is insufficient to prove the drug’s identity; however, the
proper analytical scheme encompasses a combination of test results that
characterize one and only one chemical substance—the drug under in-
vestigation. Furthermore, experimental evidence must confirm that the
 Drugs 173

probability of any other substance responding in an identical manner to

the scheme selected is so small as to be beyond any reasonable scientific
certainty.
Another consideration in selecting an analytical technique is the need
for either a qualitative or a quantitative determination. The former relates
just to the identity of the material, whereas the latter refers to the percent-
age combination of the components of a mixture. Hence, a qualitative iden-
tification of a powder may reveal the presence of heroin and quinine,
whereas a quantitative analysis may conclude the presence of 10 percent
heroin and 90 percent quinine.
Obviously, a qualitative identification must precede any attempt at
quantitation, for little value is served by attempting to quantitate a mater-
ial without first determining its identity. Essentially, a qualitative analysis
of a material requires the determination of numerous properties using a
variety of analytical techniques. On the other hand, a quantitative mea-
surement is usually accomplished by precise measurement of a single
property of the material.
Forensic chemists normally rely on several tests for a routine drug-
identification scheme: color tests, microcrystalline tests, chromatography,
spectrophotometry, and mass spectrometry.

Color Tests
Many drugs yield characteristic colors when brought into contact with
specific chemical reagents. Not only do these tests provide a useful indica-
tor of a drug’s presence, but they are also used by investigators in the field
to examine materials suspected of containing a drug (see Figure 5–11).2
However, color tests are useful for screening purposes only and are never
taken as conclusive identification of unknown drugs.
Five primary color test reagents are as follows:
1. Marquis. The reagent turns purple in the presence of heroin and mor-
phine and most opium derivatives. Marquis also becomes orange-
brown when mixed with amphetamines and methamphetamines.
2. Dillie-Koppanyi. This is a valuable screening test for barbiturates, in
whose presence the reagent turns violet-blue in color.

FIGURE 5–11 A field color

test kit for cocaine. The
suspect drug is placed in
the plastic pouch. Tubes
containing chemicals are
broken open and the color
of the chemical reaction is
oberved. Courtesy Tri-Tech,
Inc., Southport, N.C.,
www.tritechusa.com
174 C H A P T E R 5

3. Duquenois-Levine. This is a valuable color test for marijuana, performed

by adding a series of chemical solutions, to the suspect vegetation. A pos-
itive result is shown by a purple color when chloroform is added.
4. Van Urk. The reagent turns blue-purple in the presence of LSD. How-
ever, owing to the extremely small quantities of LSD in illicit prepara-
tions, this test is difficult to conduct under field conditions.
5. Scott Test. This is a color test for cocaine. A powder containing cocaine
turns a cobalt thiocyanate solution blue. Upon addition of hydrochloric
acid, the blue color is transformed to a clear pink color. Upon addition
of chloroform, if cocaine is present, the blue color reappears in the
chloroform layer.

Key Points
• Analysts use screening tests to determine the identity of drugs present
in a sample. These tests reduce the number of possible drugs to a small
and manageable number.

• A series of color tests produce characteristic colors for the more com-
monly encountered illicit drugs. In a microcrystalline test, a drop of a
chemical reagent added to a small quantity of drug on a microscope
slide produces crystals highly characteristic of a drug.

• After preliminary testing, forensic chemists use more specific tests to

identify a drug substance to the exclusion of all other known chemical
substances.

Microcrystalline Tests
A technique considerably more specific than color tests is the microcrys-
microcrystalline test talline test. A drop of a chemical reagent is added to a small quantity of
A test that identifies a specific the drug on a microscopic slide. After a short time, a chemical reaction
substance based on the color ensues, producing a crystalline precipitate. The size and shape of the
and shape of crystals formed crystals, under microscope examination, are highly characteristic of the
when the substance is mixed drug. Crystal tests for cocaine and methamphetamine are illustrated in
with specific reagents. Figure 5–12.

(a) (b)

FIGURE 5–12 (a) A photomicrograph of a cocaine crystal formed in platinum chloride

(400×). (b) A photomicrograph of a methamphetamine crystal formed in gold chloride
(400×). Courtesy David P. Blackburn, San Bernardino County Sheriff’s Department,
San Bernardino, Calif.
 Drugs 175

Over the years, analysts have developed hundreds of crystal tests to

characterize the most commonly abused drugs. These tests are rapid and
often do not require the isolation of a drug from its diluents; however, be-
cause diluents can sometimes alter or modify the shape of the crystal, the
examiner must develop experience in interpreting the results of the test.
Most color and crystal tests are largely empirical—that is, scientists do
not fully understand why they produce the results that they do. From the
forensic chemist’s point of view, this is not important. When the tests are
properly chosen and used in proper combination, their results constitute
an analytical scheme that is characteristic for one and only one drug.

Chromatography
chromatography
Chromatography is a means of separating and tentatively identifying the Any of several analytical
components of a mixture. It is particularly useful for analyzing drug speci- techniques for separating
mens, which may be diluted with practically any material in order to increase organic mixtures into their
the quantity of the product available to prospective customers. The task of components by attraction to a
identifying an illicit-drug preparation would be arduous without the aid of stationary phase while being
chromatographic methods to first separate the mixture into its components. propelled by a moving phase.

Theory of Chromatography The theory of chromatography is based on the

fact that chemical substances tend to partially escape into the surrounding
environment when dissolved in a liquid or when absorbed on a solid sur-
face. For example, if a beaker of water is covered with a bell jar, as shown
in Figure 5–13, gas molecules (represented by green balls) escape from the
water into the surrounding enclosed air. The molecules that remain are
said to be in the liquid phase; the molecules that have escaped into the air
are said to be in the gas phase.
As the gas molecules escape into the surrounding air, they accumulate
above the water; random motion carries some of them back into the water.
Eventually, a point is reached at which the number of molecules leaving the
water equals the number returning. At this time, the liquid and gas phases
are in equilibrium.
If the temperature of the water is increased, the equilibrium state read-
justs itself to a point at which more gas molecules move into the gas phase.
This behavior was first observed in 1803 by British chemist William
Henry. His explanation of this phenomenon, known appropriately as
Henry’s law, may be stated as follows: When a volatile chemical com-
pound is dissolved in a liquid and is brought to equilibrium with air,

FIGURE 5–13 Evaporation of a liquid.

176 C H A P T E R 5

there is a fixed ratio between the concentration of the volatile com-

pound in air and its concentration in the liquid, and this ratio re-
mains constant for a given temperature.
The distribution of a gas between the liquid and gas phases is determined
by the solubility of the gas; that is, how easily the gas dissolves in the liquid.
The higher its solubility, the greater the tendency of the gas molecules to re-
main in the liquid phase. If two different gases are simultaneously dissolved
in the same liquid, each reaches a state of equilibrium with the surrounding
air independently of the other. For example, as shown in Figure 5–14, gas
A (green balls) and gas B (blue balls) are both dissolved in water. At equilib-
rium, gas A has a greater number of molecules dissolved in the water than
does gas B. This is so because gas A is more soluble in water than gas B.
Thin-Layer Chromatography Thin-layer chromatography (TLC) uses a solid
stationary phase and a moving liquid phase to separate the constituents of
a mixture. Thin-layer chromatography is a powerful tool for solving many
of the analytical problems presented to the forensic scientist. The method

FIGURE 5–14 At equilibrium, there are more

gas A molecules (green balls) than gas B
molecules (blue balls) in the liquid phase.

Closer Analysis
The Chromatographic Process
In Figures 5–13 and 5–14, both phases— distance, the molecules of gas B will
liquid and gas—were kept stationary; that become entirely separated from those of
is, they were not moving. During a gas A, and the chromatographic process
chromatographic process, however, this is will be complete. This process is
not the case. Instead, one phase is always illustrated in Figure 1.
made to move continuously in one
Simply, we can think of chromatography as
direction over a stationary or fixed phase.
being analogous to a race between
For example, in Figure 5–14,
chemical compounds. At the starting line,
chromatography will occur only when the
all the participating substances are mixed
air is forced to move continuously in one
together; however, as the race progresses,
direction over the water. Because gas B
materials that prefer the moving phase
(blue balls) has a greater percentage of its
slowly pull ahead of those substances that
molecules in the moving phase than does
prefer to remain in the stationary phase.
gas A (green balls), the molecules of gas B
Finally, at the end of the race, all the
will travel over the liquid at a faster pace
participants are separated, each crossing
than those of gas A. Eventually, when the
the finish line at different times.
moving phase has advanced a reasonable
 Drugs 177

Direction
of moving
air

Stationary Liquid phase

liquid
phase
(a)

Direction
of moving
air

Stationary
liquid
phase
(b)

Direction
of moving
air

Stationary Liquid
liquid phase
phase
(c)

FIGURE 1 In this illustration of chromatography, the molecules represented by the blue

balls have a greater affinity for the upper phase and hence will be pushed along at a faster
rate by the moving air. Eventually, the two sets of molecules will seperate from each other,
completing the chromatograohic process.

The different types of chromatographic processes—gas chromatography and

systems are as varied as the number of thin-layer chromatography—are most
stationar y and moving-phase applicable for solving many analytical
combinations that can be devised. problems in the crime laborator y.
However, two chromatographic

is both rapid and sensitive; moreover, less than 100 micrograms of suspect
material are required for the analysis. In addition, the equipment necessary
for TLC work has minimal cost and space requirements. Importantly, nu-
merous samples can be analyzed simultaneously on one thin-layer plate.
This technique is principally used to detect and identify components in
complex mixtures.
Theory of thin-layer chromatography In TLC, the components of a
suspect mixture are separated as they travel up a glass plate, eventually ap-
pearing as a series of dark or colored spots on the plate. This action is then
compared to a standard sample separation of a specific drug, such as
heroin. If both the standard and the suspect substance travel the same
178 C H A P T E R 5

distance up the plate, they can tentatively be identified as being produced

by the same substance.
Figure 5–15 shows a sample suspected of containing heroin and quinine
that has been chromatographed alongside known heroin and quinine stan-
dards. The distance the unknown material migrated up the suspect plate is
compared to the distances that heroin and quinine migrated up a standard
sample plate. If the distances are the same, a tentative identification can be
made. However, such an identification cannot be considered definitive, for
numerous other substances can migrate the same distance up the plate
when chromatographed under similar conditions. Thus, thin-layer chro-
matography alone cannot provide an absolute identification; it must be used
in conjunction with other testing procedures to prove absolute identity.
TLC in practice. A thin-layer plate is prepared by coating a glass plate
or plastic backing with a thin film of a granular material, usually silica gel
or aluminum oxide. This granular material serves as the solid stationary
phase and is usually held in place on the plate with a binding agent such as
plaster of Paris. If the sample to be analyzed is a solid, it must first be dis-
solved in a suitable solvent and a few microliters of the solution spotted
with a capillary tube onto the granular surface near the lower edge of the
plate. A liquid sample may be applied directly to the plate in the same man-
ner. The plate is then placed upright into a closed chamber that contains a
selected liquid, with care that the liquid does not touch the sample spot.

FIGURE 5–15 Chromatograms of known heroin

(1) and quinine (2) standards alongside suspect
sample (3).
 Drugs 179

The liquid slowly rises up the plate by capillary action. This rising liq-
uid is the moving phase in thin-layer chromatography. As the liquid moves
past the sample spot, the components of the sample become distributed
between the stationary solid phase and the moving liquid phase. The com-
ponents with the greatest affinity for the moving phase travel up the plate
faster than those that have greater affinity for the stationary phase. When
the liquid front has moved a sufficient distance (usually 10 cm), the devel-
opment is complete, and the plate is removed from the chamber and dried
(see Figure 5–16). An example of the chromatographic separation of ink is
shown in Figure 5–17.
Because most compounds are colorless, no separation will be noticed
after development unless the materials are visualized. To accomplish fluoresce
this, the plates are placed under ultraviolet light, revealing fluorescent ma- To emit visible light when
terials (those that emit visible light when exposed to light of a shorter exposed to light of a shorter
wavelength) as bright spots on a dark background. When a fluorescent dye wavelength—that is, ultraviolet
has been incorporated into the solid phase, nonfluorescent substances light.

Very thin coating of

silica gel or
aluminum oxide
Sample
spot

(a)

Rising solvent; original

spot has separated
into several spots

(b)

FIGURE 5–16 (a) In thin-layer chromatography, a liquid sample is spotted onto the
granular surface of a gel-coated plate. (b) The plate is placed into a closed chamber that
contains a liquid. As the liquid rises up the plate, the components of the sample distribute
themselves between the coating and the moving liquid. The mixture is separated, with
substances with a greater affinity for the moving liquid traveling up the plate at a faster
speed.
180 C H A P T E R 5

(a) (b) (c)

FIGURE 5–17 (a) The liquid phase begins to move up the stationary phase. (b) Liquid
moves past the ink spot carrying the ink components up the stationary phase. (c) The
moving liquid has separated the ink into its several components.

FIGURE 5–18 Thin-layer chromatogram of a

marijuana extract. Courtesy Sirchie Finger Print
Laboratories, Inc., Youngsville, N.C., www.sirchie.com

appear as dark spots against a fluorescent background when exposed to

the ultraviolet light. In a second method of visualization, the plate is sprayed
with a chemical reagent that reacts with the separated substances and
causes them to form colored spots. Figure 5–18 shows the chromatogram
of a marijuana extract that has been separated into its components by TLC
and visualized by having been sprayed with a chemical reagent.
The distance a spot has traveled up a thin-layer plate can be assigned a
numerical value known as the Rf value. This value is defined as the distance
traveled by the component divided by the distance traveled by the moving
 Drugs 181

liquid phase. For example, in Figure 5–15 the moving phase traveled
10 centimeters up the plate before the plate was removed from the tank.
After visualization, the heroin spot moved 8 centimeters, for an Rf value of
0.8; the quinine migrated 4 centimeters, for an Rf value of 0.4.

Gas Chromatography (GC) Gas chromatography (GC) separates mixtures

based on their distribution between a stationary liquid phase and a mov-
ing gas phase. In gas chromatography, the moving phase is called the
carrier gas, which flows through a column constructed of stainless steel or
glass. The stationary phase is a thin film of liquid within the column.
Two types of columns used: the packed column and the capillary col-
umn. With the packed column, the stationary phase is a thin film of liquid
fixed onto small granular particles packed into the column. This column,
usually constructed of stainless steel or glass, is 2 to 6 meters long and
about 3 millimeters in diameter. Capillary columns are composed of glass
and are much longer than packed columns—15 to 60 meters in length.
These types of columns are very narrow, ranging from 0.25 to 0.75 mil-
limeter in diameter. Capillary columns can be made narrower than packed
columns because their stationary liquid phase is actually coated as a very
thin film directly onto the column’s inner wall.
As the carrier gas flows through the packed or capillary column,
it carries with it the components of a mixture that have been injected
into the column. Components with a greater affinity for the moving
gas phase travel through the column more quickly than those with a
greater affinity for the stationary liquid phase. Eventually, after the mix-
ture has traversed the length of the column, it emerges separated into
its components.
The time required for a component to emerge from the column from
the time of its injection into the column is known as the retention time,
which is a useful identifying characteristic of a material. Figure 5–20(a)
shows the chromatogram of two barbiturates; each barbiturate has tenta-
tively been identified by comparing its retention time to those of known
barbiturates, shown in Figure 5–20(b). However, because other substances WebExtra 5.1
Watch Animated Depictions
may have comparable retention times under similar chromatographic con-
of Thin-Layer Chromatography
ditions, gas chromatography cannot be considered an absolute means of and Gas Chromatography
identification. Conclusions derived from this technique must be confirmed www.prenhall.com/hsforensics
by other testing procedures.
Gas chromatography is widely used because of its ability to resolve a
highly complex mixture into its components, usually within minutes. It has
an added advantage in that it is extremely sensitive and can yield quanti- WebExtra 5.2
tative results. Gas chromatography has sufficient sensitivity to detect and Watch the Gas
quantitate materials at the nanogram (0.000000001 gram or 1 ⫻ 10⫺9 gram) Chromatograph at Work
level.3 www.prenhall.com/hsforensics

Spectrophotometry
The technique of chromatography is particularly suited for analyzing il-
licit drugs, because it can separate a drug from other substances that
may be present in the drug preparation. However, chromatography has
the drawback of not being able to specifically identify the material under
investigation. For this reason, other analytical tools are frequently used
to identify drugs. These include the technique of spectrophotometry,
which can identify a substance by exposing it to a specific type of elec-
tromagnetic radiation.
182 C H A P T E R 5

Closer Analysis
The Gas Chromatograph
A simplified scheme of the gas the proper liquid phase and has made the
chromatograph is shown in Figure 5–19. column long enough, the components of
The operation of the instrument can be the sample will be completely separated
summed up briefly as follows: The carrier as they emerge from the column.
gas is fed into the column at a constant
As each component emerges from the
rate. The carrier gas is chemically inert
column, it enters a detector. One type of
and is generally nitrogen or helium. The
detector uses a flame to ionize the
sample under investigation is injected as a
emerging chemical substance, thus
liquid into a heated injection port with a
generating an electrical signal. The signal
syringe, where it is immediately vaporized
is recorded on a strip-chart recorder as a
and swept into the column by the carrier
function of time. This written record of the
gas. The column itself is heated in an oven
separation is called a chromatogram. A
in order to keep the sample in a vapor
gas chromatogram is a plot of the recorder
state as it travels through the column. In
response (vertical axis) versus time
the column, the components of the sample
(horizontal axis). A typical chromatogram
travel in the direction of the carrier gas
shows a series of peaks, each peak
flow at speeds that are determined by their
corresponding to one component of the
distribution between the stationary and
mixture.
moving phases. If the analyst has selected

3
4
1
2
1. Sample
2. Injector
3. Carrier gas
4. Column
5. Detector
6. Power supply
7. Recorder
8. Chromatogram 6 5

8
7

FIGURE 5–19 Basic gas chromatography. Gas chromatography permits rapid separation of
complex mixtures into individual compounds and allows identification and quantitative
determination of each compound. As shown, a sample is introduced by a syringe (1) into a
heated injection chamber (2). A constant stream of nitrogen gas (3) flows through the
injector, carrying the sample into the column (4), which contains a thin film of liquid. The
sample is separated in the column, and the carrier gas and separated components emerge
from the column and enter the detector (5). Signals developed by the detector activate the
recorder (7), which makes a permanent record of the separation by tracing a series of
peaks on the chromatograph (8). The time of elution identifies the component present, and
the peak area identifies the concentration. Courtesy Varian Inc., Palo Alto, Calif.
 Drugs 183

Pentobarbital

Secobarbital

0 1 2 3 4 5 6 7 8 9 10 11 12
(a) TIME (MINUTES)

Amobarbital

Butabarbital
Pentobarbital

Secobarbital

Phenobarbital

0 1 2 3 4 5 6 7 8 9 10 11 12
(b) TIME (MINUTES)

FIGURE 5–20 (a) An unknown mixture of barbiturates is identified by comparing its

retention times to (b), a known mixture of barbiturates. Courtesy Varian Inc., Palo Alto, Calif.

Theory of Spectrophotometry We have already observed in the description spectrophotometry

of color that an object does not absorb all the visible light it is exposed to; An analytical method for
instead, it selectively absorbs some frequencies and reflects or transmits identifying a substance by its
others. Simlarly, the absorption of other types of electromagnetic radiation selective absorption of
by chemical substances is also selective. Selective absorption of a different wavelengths of light.
184 C H A P T E R 5

substance is measured by an instrument called a spectrophotometer, which

produces a graph or absorption spectrum that depicts the absorption of
light as a function of wavelength or frequency. The absorption of ultravio-
let (UV), visible, and infrared (IR) radiation is particularly applicable for
obtaining qualitative data pertaining to the identification of drugs.
Absorption at a single wavelength or frequency of light is not 100 per-
cent complete—some radiation is transmitted or reflected by the material.
Just how much radiation a substance absorbs is defined by a fundamental
relationship known as Beer’s law, shown in Equation (5–1):

A ⫽ kc (5–1)

Here, A symbolizes the absorption or the quantity of light taken up at a sin-

gle frequency, c is the concentration of the absorbing material, and k is a
proportionality constant. This relationship shows that the quantity of light
absorbed at any frequency is directly proportional to the concentration of
the absorbing species; the more material you have, the more radiation it
will absorb. By defining the relationship between absorbance and concen-
tration, Beer’s law permits spectrophotometry to be used as a technique
for quantification.

ultraviolet Ultraviolet and Visible Spectrophotometry Ultraviolet (UV) and visible spec-
Invisible long frequencies of trophotometry measure the absorbance of UV and visible light as a function
light beyond violet in the of wavelength or frequency. For example, the UV absorption spectrum of
visible spectrum. heroin shows a maximum absorption band at a wavelength of 278 nanome-
ters (see Figure 5–21). This shows that the simplicity of a UV spectrum fa-
cilitates its use as a tool for determining a material’s probable identity. For
instance, a white powder may have a UV spectrum comparable to heroin

Heroin
Absorbance

250 300 350

Wavelength in nanometers

FIGURE 5–21 Ultraviolet spectrum of heroin.

 Drugs 185

and therefore may be tentatively identified as such. (Fortunately, sugar and

starch, common diluents of heroin, do not absorb UV light.)
This technique, however, does not provide a definitive result; other
drugs or materials may have a UV absorption spectrum similar to that of
heroin. Nevertheless, UV spectrophotometry is often useful in establishing
the probable identity of a drug. For example, if an unknown substance yields
a UV spectrum that resembles that of amphetamine (see Figure 5–22), thou-
sands of substances are immediately eliminated from consideration, and the
analyst can begin to identify the material from a relatively small number of
possibilities. A comprehensive collection of UV drug spectra provides an
index that can rapidly be searched in order to tentatively identify a drug or,
failing that, at least to exclude certain drugs from consideration.

Infrared Spectrophotometry In contrast to the simplicity of a UV spectrum,

absorption in the infrared region provides a far more complex pattern. infrared
Figure 5–23 depicts the IR spectra of heroin and secobarbital. Here, the ab- Invisible short frequencies of
sorption bands are so numerous that each spectrum can provide enough light before red in the visible
characteristics to identify a substance specifically. Different materials al- spectrum.
ways have distinctively different infrared spectra; each IR spectrum is
therefore equivalent to a “fingerprint” of that substance and no other.
This technique is one of the few tests available to the forensic scientist that
can be considered specific in itself for identification. The IR spectra of thou-
sands of organic compounds have been collected, indexed, and cataloged WebExtra 5.3
as invaluable references for identifying organic substances. The selective See How a
absorption of light by drugs in the UV and IR regions of the electromagnetic Spectrophotometer Works
spectrum provides a valuable technique for characterizing drugs. www.prenhall.com/hsforensics

Amphetamine
Absorbance

250 300 350

Wavelength (nanometers)

FIGURE 5–22 Ultraviolet spectrum of amphetamine.

186 C H A P T E R 5

100.00
%T

0.00
4000 3500 3000 2500 2000 1500 1000 500
Wavenumber cm–1

(a)

100.00
%T

0.00
4000 3500 3000 2500 2000 1500 1000 500
Wavenumber cm–1

(b)

FIGURE 5–23 (a) Infrared spectrum of heroin. (b) Infrared spectrum of secobarbital.
 Drugs 187

Closer Analysis
The Spectrophotometer
The spectrophotometer measures and made by scratching thousands of parallel
records the absorption spectrum of a lines on a transparent surface such as
chemical. The basic components of a glass. As light passes through the narrow
simple spectrophotometer are the same spacings between the lines, it spreads out
regardless of whether it is designed to and produces a spectrum similar to that
measure the absorption of UV, visible, or formed by a prism. The desired wavelength
IR radiation. These components are is obtained when the dispersed radiation is
illustrated diagrammatically in the figure. focused onto a narrow slit that permits
They include (1) a radiation source, (2) a only selected wavelengths to pass through.
monochromator or frequency selector,
Most laboratory infrared spectrophotometers
(3) a sample holder, (4) a detector to
use Fourier transform analysis to measure
convert electromagnetic radiation into an
the wavelengths of light at which a material
electrical signal, and (5) a recorder to
absorbs in the infrared spectrum. This
produce a record of the signal.
approach does not use any dispersive
The choice of source varies with the type elements that select single wavelengths or
of radiation desired. For visible radiation, frequencies of light emitted from a source;
an ordinary tungsten bulb provides a instead, the heart of a Fourier transform
convenient source of radiation. In the UV infrared (FT-IR) spectrometer is the
region, a hydrogen or deuterium discharge Michelson interferometer. The
lamp is normally used, and a heated interferometer uses a beam-splitting prism
molded rod containing a mixture of rare- and two mirrors, one movable and one
earth oxides is a good source of IR light. stationary, to direct light toward a sample.
As the wavelengths pass through the
The function of the monochromator is to monochromator
sample and reach a detector, they are all
select a single wavelength or frequency of A device for isolating individual
measured simultaneously. A mathematical
light from the source—monochromatic wavelengths or frequencies of
operation, the Fourier transform method, is light.
light. Some inexpensive
used to decode the measured signals and
spectrophotometers pass the light
record the wavelength data. These Fourier monochromatic light
through colored glass filters to remove all
calculations are rapidly carried out by a Light having a single
radiation from the beam except for a
computer. In a matter of seconds, a wavelength or frequency.
desired range of wavelengths.
computer-operated FT-IR instrument can
More precise spectrophotometers may use produce an infrared absorption pattern
a prism or diffraction grating to disperse compatible to one generated by a prism
radiation into its component wavelengths instrument.
or frequencies. A diffraction grating is

Prism disperses radiation

into component wavelengths

Prism Slit
Radiation source Monochromator Sample cell Detector Recorder

(a)

(continued)
188 C H A P T E R 5

Closer Analysis
The Spectrophotometer (continued)
Slit allows only selected wavelengths or
frequencies of radiation to pass through

Prism Slit
Radiation source Monochromator Sample cell Detector Recorder

(b)

Radiation passes through

sample, which absorbs
certain frequencies

Prism Slit
Radiation source Monochromator Sample cell Detector Recorder

(c)

Prism Slit
Radiation source Monochromator Sample Detector measures Recorder
cell absorption of radiation
by the sample and
converts the radiation
into an electrical signal

(d)

Recorder translates electrical signal into

recording of the absorption spectrum

Prism Slit
Radiation source Monochromator Sample cell Detector Recorder
The absorption spectrum of
a chemical substance allows
spectrophotometry to be used
for identification.

(e)

Spectrophotometry.
 Drugs 189

Sample preparation varies with the type of by converting it to an electrical signal. UV

radiation being studied. Absorption spectra and visible spectrophotometers use
in the UV and visible regions are usually photoelectric tube detectors. A signal is
obtained from samples that have been generated when the photons strike the
dissolved in an appropriate solvent. tube surface to produce a current that is
Because the cells holding the solution directly proportional to the intensity of the
must be transparent to the light being light transmitted through the sample.
measured, glass cells are used in the When this signal is compared to the
visible region and quartz cells in the intensity of light that is transmitted to the
ultraviolet region. Practically all substances detector in the absence of an absorbing
absorb in some region of the IR spectrum, material, the absorbance of a substance
so sampling techniques must be modified can be determined at each wavelength or
to measure absorption in this spectral frequency of light selected. The signal from
region; special cells made out of sodium the detection system is then fed into a
chloride or potassium bromide are recorder, which plots absorbance as a
commonly used because they do not function of wavelength or frequency.
absorb light over a wide range of the IR Modern spectrophotometers are designed
portion of the electromagnetic spectrum. to trace an entire absorption spectrum
automatically.
The detector measures the quantity of
radiation that passes through the sample

Mass Spectrometry
A previous section discussed the operation of the gas chromatograph. This
instrument is one of the most important tools in a crime laboratory. Its abil-
ity to separate the components of a complex mixture is unsurpassed. How-
ever, gas chromatography has one important drawback— its inability to
produce specific identification. A forensic chemist cannot unequivocally state
the identification of a substance based solely on a retention time as deter-
mined by the gas chromatograph. Fortunately, by coupling the gas chro-
matograph to a mass spectrometer this problem has largely been overcome.
A mixture’s components are first separated on the gas chromatograph.
A direct connection between the gas chromatograph column and the mass
spectrometer then allows each component to flow into the spectrometer as
it emerges from the gas chromatograph. In the mass spectrometer, the
material enters a high-vacuum chamber where a beam of high-energy
electrons is aimed at the sample molecules. The electrons collide with the
molecules, causing them to lose electrons and to acquire a positive charge.
These positively charged molecules, or ions, are very unstable or are ion
formed with excess energy and almost instantaneously decompose into An atom or molecule bearing a
numerous smaller fragments. The fragments then pass through an electric positive or negative charge.
or magnetic field, where they are separated according to their masses. The
unique feature of mass spectrometry is that under carefully controlled
conditions, no two substances produce the same fragmentation pattern. In
essence, one can think of this pattern as a “fingerprint” of the substance
being examined (see Figure 5–24).
190 C H A P T E R 5

GC
MS

Separation Identification

C A
A B
B D C
D
Chromatogram Spectra

FIGURE 5–24 How GC/MS works. Left to right, the sample is separated into its
components by the gas chromatograph, and then the components are ionized and identified
by characteristic fragmentation patterns of the spectra produced by the mass
spectrometer. Courtesy Agilent Technologies, Inc., Palo Alto, Calif.

The technique thus provides a specific means for identifying a chemical

structure. It is also sensitive to minute concentrations. Mass spectrometry is
mostly widely used to identify drugs; however, further research is expected
to yield significant applications to identifying other types of physical evi-
dence. Figure 5–25 illustrates the mass spectra of heroin and cocaine; here,
each line represents a fragment of a different mass (actually the ratio of mass
to charge), and the line height reflects the relative abundance of each frag-
ment. Note how different the fragmentation patterns of heroin and cocaine
are. Each mass spectrum is unique to each drug and therefore provides a
specific test for identifying that substance.
The combination of the gas chromatograph and mass spectrometer
(GC/MS) is further enhanced when a computer is added to the system.
The integrated gas chromatograph/mass spectrometer/computer sys-
tem provides the ultimate in speed, accuracy, and sensitivity. With the
ability to record and store in its memory several hundred mass spectra,
such a system can detect and identify substances present in only one-
millionth-of-a-gram quantities. Furthermore, the computer can be pro-
grammed to compare an unknown spectrum against a comprehensive
library of mass spectra stored in its memory. The advent of personal
computers and microcircuitry has made it possible to design mass spec-
WebExtra 5.4 trometer systems that can fit on a small table. Such a unit is pictured in
Watch the Gas
Figure 5–26. With data obtained from a GC/MS determination, a foren-
Chromatograph/Mass sic analyst can, with one instrument, separate the components of a com-
Spectrometer at Work plex drug mixture and then unequivocally identify each substance
www.prenhall.com/hsforensics present in the mixture.
 Drugs 191

369
43 327
268
Abundance

204
215
94 146

100 200 300

Mass/charge
(a)

182
82
Abundance

303
42

122 272
150

50 100 150 200 250 300

Mass/charge
(b)

FIGURE 5–25 (a) Mass spectrum of heroin. (b) Mass spectrum of cocaine.

1. Injection port 3. Ion source

4. Quadrupole 6. Data system

2. GC column 5. Detector

FIGURE 5–26 A tabletop mass spectrometer. (1) The sample is injected into a heated
inlet port, and a carrier gas sweeps it into the column. (2) The GC column separates the
mixture into its components. (3) In the ion source, a filament wire emits electrons that
strike the sample molecules, causing them to fragment as they leave the GC column.
(4) The quadrupole, consisting of four rods, separates the fragments according to their
mass. (5) The detector counts the fragments passing through the quadrupole. The signal is
small and must be amplified. (6) The data system is responsible for total control of the
entire GC/MS system. It detects and measures the abundance of each fragment and
displays the mass spectrum. Courtesy Agilent Technologies, Inc., Palo Alto, Calif.
192 C H A P T E R 5

FIGURE 5–27 A scientist

injecting a sample into a
research-grade mass
spectrometer. Courtesy
Geoff Tompkinson/Science
Photo Library

Research-grade mass spectrometers are found in laboratories as larger

floor-model units (see Figure 5–27).

Key Points
• Chromatography is a means of separating and tentatively identifying
the components of a mixture.

• TLC uses a solid stationary phase, usually coated onto a glass plate, and
a mobile liquid phase to separate the components of the mixture.

• Gas chromatography (GC) separates mixtures on the basis of their dis-

tribution between a stationary liquid phase and a mobile gas phase.

• Spectrophotometry is the study of the absorption of light by chemical

substances.

• Most forensic laboratories use ultraviolet (UV) and infrared (IR) spec-
trophotometers to characterize chemical compounds.

• IR spectrophotometry provides a far more complex pattern than UV

spectrophotometry. Because different materials have distinctively dif-
ferent infrared spectra, each IR spectrum is equivalent to a “finger-
print” of that substance.

• Mass spectrometry characterizes organic molecules by observing their

fragmentation pattern after their collision with a beam of high-energy
electrons.

• Infrared spectrophotometry and mass spectrophotometry typically are

used to specifically identify a drug substance.
 Drugs 193

Collection and Preservation

of Drug Evidence
Preparation of drug evidence for submission to the crime laboratory is
normally relatively simple, accomplished with minimal precautions in the
field. The field investigator must ensure that the evidence is properly pack-
aged and labeled for delivery to the laboratory. Considering the countless
forms and varieties of drug evidence seized, it is not practical to prescribe
any single packaging procedure for fulfilling these requirements. Gener-
ally, common sense is the best guide in such situations, keeping in mind
that the package must prevent loss and/or cross-contamination of the con-
tents. Often, the original container in which the drug was seized will suf-
fice to meet these requirements. Specimens suspected of containing
volatile solvents, such as those involved in glue-sniffing cases, must be
packaged in an airtight container to prevent evaporation of the solvent. All
packages must be marked with sufficient information to ensure identifica-
tion by the officer in future legal proceedings and to establish the chain of
custody.
To aid the drug analyst, the investigator should supply any background
information that may relate to a drug’s identity. Analysis time can be
markedly reduced when the chemist has this information. For the same
reason, the results of drug-screening tests used in the field must also be
transmitted to the laboratory. However, although these tests may indicate
the presence of a drug and may help the officer establish probable cause
to search and arrest a suspect, they do not offer conclusive evidence of a
drug’s identity.

Chapter Summary
A drug can be defined as a natural or synthetic substance that is used to
produce physiological or psychological effects in humans or other animals.
Narcotic drugs are analgesics, meaning they relieve pain by depressing the
central nervous system. Regular use of a narcotic drug leads to physical de-
pendence. The most common source of narcotic drugs is opium. Morphine
is readily extracted from opium and is used to synthesize heroin. Opiates,
which include methadone and OxyContin (oxycodone), are not derived
from opium or morphine, but they have the same physiological effects on
the body as opium narcotics.
Another class of drugs is hallucinogens; marijuana is the most well-
known member of this class. Hallucinogens cause marked changes in
thought processes, perceptions, and moods. Marijuana is the most contro-
versial drug in this class because its long-term effects on health are still
194 C H A P T E R 5

largely unknown. Other hallucinogens include LSD, mescaline, PCP, psilo-

cybin, and MDMA (Ecstasy).
Depressants are drugs that slow the central nervous system. These
include alcohol (ethanol), barbiturates, tranquilizers, and various substances
that can be sniffed, such as airplane glue and model cement. Stimulants have
the opposite effect; they increase the activity of the central nervous system.
Stimulants include amphetamines, sometimes known as “uppers” or
“speed,” and cocaine, which in its freebase form is known as crack.
The term club drugs refers to synthetic drugs that are used at night-
clubs, bars, and raves (all-night dance parties). Substances that are of-
ten used as club drugs include, but are not limited to, MDMA (Ecstasy),
GHB (gamma hydroxybutyrate), Rohypnol (“Roofies”), ketamine, and
methamphetamine.
Anabolic steroids are synthetic compounds that are chemically related
to the male sex hormone testosterone. Anabolic steroids are often abused
by individuals who want to accelerate muscle growth.
Federal law establishes five schedules of classification for controlled
dangerous substances on the basis of a drug’s potential for abuse, poten-
tial for physical and psychological dependence, and medical value.
Analysts use screening tests to determine whether a sample contains
one or more commonly encountered illicit drugs. These tests include color
tests that produce characteristic colors for certain drugs. Once this pre-
liminary analysis is completed, a forensic scientist performs a confirmation
test to identify a drug substance to the exclusion of all other known chem-
ical substances.
Chromatography, spectrophotometry, and mass spectrometry are all
readily used by forensic scientists to identify illicit drugs. Chromatography
is a means of separating and tentatively identifying the components of a
mixture. Gas chromatography (GC) separates mixtures based on their
distribution between a stationary liquid phase and a mobile gas phase.
Thin-layer chromatography (TLC) uses a solid stationary phase, usually
coated onto a glass plate, and a mobile liquid phase to separate the compo-
nents of the mixture. Spectrophotometry is the study of the absorption of
light by chemical substances. Mass spectrometry characterizes organic
molecules by observing their fragmentation pattern after their collision
with a beam of high-energy electrons. By connecting a GC to a mass spec-
trometer, the forensic scientist can capture a unique “fingerprint” of the
substance being examined.
Most forensic laboratories use ultraviolet (UV) or infrared (IR) spec-
trophotometers to characterize chemical compounds. Absorption in the
infrared region provides a far more complex pattern than absorption in the
UV spectrum. Different materials always have distinctively different in-
frared spectra; each IR spectrum is therefore equivalent to a “fingerprint”
of that substance.
 Drugs 195

Review Questions
Facts and Concepts
1. What is a drug? How has drug use affected the growth of crime laboratories
in the United States?

2. Name three nondrug factors that play a part in drug dependence.

3. Define physical dependence and psychological dependence.

4. Physical dependence develops only when the drug user

a. takes large doses of a drug.
b. takes one drug to the exclusion of all others.
c. uses a drug on a regular schedule.
d. has used a drug for at least six months.
5. What is the most important factor to consider when evaluating the social im-
pact of drug dependence on an individual?

6. What is the pharmacological definition of a narcotic?

7. What is the source of most narcotic analgesics? Name two popular drugs pre-
pared from this substance.

8. Name two synthetic opiates and describe the purpose for which each typically
is used.

9. What is a hallucinogen? Name three commonly used hallucinogens.

10. What is the most widely used illicit drug in the United States? What is the ac-
tive ingredient in this drug?

11. Arrange the following parts or products of the Cannabis plant in order of THC
content, from highest to lowest concentration of THC: flowers, leaves, resin,
seeds, stem.

12. List three potential medical uses of marijuana.

13. What is angel dust and what are the negative consequences of long-term use?
14. What is the most widely abused drug in the United States?

15. In what class of drugs do alcohol and barbiturates belong? What is the main
physiological effect of such drugs?

16. What is huffing?

17. What is a stimulant? Name two widely used stimulants.

18. Name two potent forms of methamphetamine. How is each of these drugs
typically taken into the body?
196 C H A P T E R 5

19. What popular stimulant is derived from a plant that grows in the Andes
mountains of South America?

20. What is crack and how is it produced?

21. Name club drugs belonging to three different classes of drugs, and indicate
the class to which each belongs.

22. What are anabolic steroids and why were they developed?

23. What are the two phases in a forensic scientist’s analytical scheme?

24. What is the difference between a screening test and a confirmation test?

25. Name two types of empirical tests used to identify drugs. Why are these tests
referred to as empirical?

26. What is the difference between a qualitative evaluation and a quantitative

evaluation?

27. Why is chromatography particularly well suited to the needs of a drug analyst?

28. In chromatography, the distribution of a gas between the liquid and gas
phases is determined by
a. the density of the gas relative to the liquid.
b. the volume of the gas in the container.
c. the solubility of the gas in the liquid.
d. the mass of the gas relative to the liquid.
29. Explain how chromatography is like a race between chemical compounds.

30. Name three distinct advantages of gas chromatography in the identification

of drugs.

31. What is the main drawback of gas chromatography in the identification of

drugs?

32. What phenomenon forms the basis of spectrophotometry?

33. What is the main advantage of infrared spectrophotometry over ultraviolet or

visible-light spectrophotometry?

34. With what analytical device is a gas chromatograph often connected to ana-
lyze drug mixtures, and why?
 Drugs 197

Application and Critical Thinking

1. An individual who has been using a drug for an extended period of time sud-
denly finds himself unable to secure more of the drug. He acts nervous and
irritable and is hyperactive. He seems almost desperate to find more of the
drug, but experiences no sickness, pain, or other outward physical discom-
fort. Based on his behavior, what drugs might he possibly have been using?
Explain your answer.

2. Following are descriptions of behavior that are characteristic among users of

certain classes of drugs. For each description, indicate the class of drug (nar-
cotics, stimulants, and so on) for which the behavior is most characteristic.
For each description, also name at least one drug that produces the described
effects.
a. slurred speech, slow reaction time, impaired judgment, reduced coordination
b. intense emotional responses, anxiety, altered sensory perceptions
c. alertness, feelings of strength and confidence, rapid speech and move-
ment, decreased appetite
d. drowsiness, intense feeling of well-being, relief from pain
3. Following are descriptions of four hypothetical drugs. According to the Con-
trolled Substances Act, under which drug schedule would each substance be
classified?
a. This drug has a high potential for psychological dependence, it currently
has accepted medical uses in the United States, and the distributor is not
required to report to the U.S. Drug Enforcement Administration.
b. This drug has medical use in the United States, is not limited by manufac-
turing quotas, and may be exported without a permit.
c. This drug must be stored in a vault or safe, requires separate record keep-
ing, and may be distributed with a prescription.
d. This drug may not be imported or exported without a permit, is subject
to manufacturing quotas, and currently has no medical use in the United
States.
4. A police officer stops a motorist who is driving erratically and notices a bag
of white powder on the front seat of the car that he suspects contains heroin.
The officer brings the bag to you, a forensic scientist in the local crime lab.
Name one screening test that you might perform to determine the presence
of heroin. Assuming the powder tests positive for heroin, what should you
do next?

5. The figure on page 198 shows a chromatogram of a known mixture of barbi-

turates. Based on this figure, answer the following questions:
a. What barbiturate detected by the chromatogram had the longest retention
time?
b. Which barbiturate had the shortest retention time?
c. What is the approximate retention time of amobarbital?
198 C H A P T E R 5

Amobarbital

Butabarbital
Pentobarbital

Secobarbital

Phenobarbital

0 1 2 3 4 5 6 7 8 9 10 11 12
(b) TIME (MINUTES)

Web Resources
Drugs.com (Extensive database of information about the use and effects of 24,000
different drugs)
www.drugs.com
National Institute on Drug Abuse (Division of the National Institute of Health with
links to information about effects of and studies about legal and illicit drugs)
www.nida.nih.gov
General Alcohol Information (Fact sheet on impact of alcohol use on accidents,
injuries, violence, unwanted pregnancy, and other areas of public health and welfare)
www.cdc.gov/alcohol/factsheets/general_information.htm
Impaired Driving Facts (Statistics compiled by the National Center for Injury
Prevention and Control)
www.cdc.gov/ncipc/factsheets/drving.htm
Neuroscience for Kids (Information about the history, production, use, effects, and
detection of the drugs discussed in the text)
faculty.washington.edu/chudler/introb.html#drug
Drugs of Abuse (A publication of the Drug Enforcement Administration decribing
illicit drugs)
www.dea.gov/pubs/abuse/index.htm
StreetDrugs.org (Extensive information about the history and effects of hundreds of
different legal and illicit drugs)
www.streetdrugs.org
Drug Schedules (List of substances classified under each section of the U.S. federal
narcotics laws)
www.mspta.com/dre/pdf/Drug_Schedules.pdf
Chromatography (Simple description of chromatographic processes with diagrams)
antoine.frostburg.edu/chem/senese/101/matter/chromatography.shtml
 Drugs 199

Basic Principles of Spectrophotometry (Online simulation of a spectrophotometer)

www.chm.davidson.edu/ChemistryApplets/spectrophotometry/Spectrophotometry.html
Beer’s Law (Online experiment applying Beer’s law using spectrophotometer
simulation)
www.chm.davidson.edu/ChemistryApplets/spectrophotometry/BeersLaw.html

Endnotes
1. Marijuana—A Signal of Misunderstanding (Washington, D.C.: U.S. Government
Printing Office, 1972), p. 56.
2. Field-test color kits for drugs can be purchased from various commercial
manufacturers.
3. Powers of 10 are quite useful and simple for handling large or small numbers.
The exponent expresses the number of places the decimal point must be moved. If
it is positive, the decimal point is moved to the right; if it is negative, the decimal
point is moved to the left. Thus, to express 1 ⫻ 10⫺9 as a number, the decimal point
is simply moved nine places to the left of 1.