Q1 ANALYTICAL LABORATORY EQUIPMENT?
1. Mass spectrometry
Mass spectrometry is an analytical tool useful for measuring the mass-to-charge
ratio (m/z) of one or more molecules present in a sample. These measurements
can often be used to calculate the exact molecular weight of the sample
components as well
Titrator ;
A Titrator consists basically of an electric burette, a sensor whose signal is
amplified with an preamplifier and a microcomputer. During a titration,
the Titrator measures the signal of the sensor and uses this information to control
the addition of the titrant with the electric burette.
2. Spectrometer ;
A spectrometer is any instrument used to probe a property of light as a function of
its portion of the electromagnetic spectrum, typically its wavelength, frequency,
or energy. The property being measured is usually intensity of light, but other
variables like polarization can also be measured.
3. Rheometer ;
A Rheometer is a laboratory device used to measure the way in which a liquid,
suspension or slurry flows in response to applied forces. It is used for those fluids
which cannot be defined by a single value of viscosity and therefore require
more parameters to be set and measured than is the case for a viscometer.
4. pH meter
The pH meter is an electrical device that determines the acidity or basicity of
aqueous solutions, one of the most commonly monitored parameters. To use a pH
meter, the pH electrode is first calibrated with standard buffer solutions with
known pH values that span the range being measured
5. Weighing balance
A weighing balance is an instrument which is used to determine the weight or
mass of an object feeds sample. Available in a wide range of sizes with
multiple weighing capacities they are essential tools in laboratories.
6. THERMAL ANALYSER ;
These instruments typically measure heat flow, weight loss, dimension change,
or mechanical properties as a function of temperature.
7. Colorimeter ;
A colorimeter is a device used in colorimetry that measures the absorbance of
particular wavelengths of light by a specific solution. It is commonly used to
determine the concentration of a known solute in a given solution.
Question 2
IF AFEED IS REPRESENTATIVE THEN FEED IS CONSIDER AS THE VERY
FOUNDITION IN RESEARCH STUDIES WHY?
ANSWER.
If the feed is representative then it will be the foundation for research purpose
because the representative feed sample have specific calculated value ie Cf ,CP
DM AND ASH etc so this feed will be easily adjusted for formulation of a
balance ration. therefore representative feed is used as foundation for research
studies.
HOW 2KG REPRESENTATIVE SAMPLE CAN BE OBTAINED FROM A
LOT OF 20 KG ?
ANSWER :
The feed should be sun drying which contain 65% moisture then it will become
approximately 8 kg.
The dry sample then grind by grinding machine and made 4 representative
samples which have specific nutritional value.
Then randomly take 2kg representative sample for further analysis.
Question 3;
HOW MINERALS ARE ESTIMATED IN A FEED SAMPLE ?
The ash content is a measure of the total amount of minerals present within a food, whereas
the mineral content is a measure of the amount of specific inorganic components present within a
food, such as Ca, Na, K and Cl.
Determination of the ash and mineral content of foods is important for a number of
reasons:
Nutritional labeling.
The concentration and type of minerals present must often be stipulated on the
label of a food.
Quality.
The quality of many foods depends on the concentration and type of minerals they
contain, including their taste, appearance, texture and stability.
Microbiological stability.
High mineral contents are sometimes used to retard the growth of certain
microorganisms.
Nutrition.
Some minerals are essential to a healthy diet (e.g., calcium, phosphorous,
potassium and sodium) whereas others can be toxic (e.g., lead, mercury, cadmium
and aluminum).
Processing.
It is often important to know foods the mineral content of foods during processing
because this affects the physicochemical properties of foods.
THERE ARE DIFFERENT METHOD OF MINERALS ESTIMATION
BUT DRY ASHING IS THE ACCUTATE METHOD OF MINERALS
ESTIMATION.
Dry Ashing
Dry ashing procedures use a high temperature muffle furnace capable of
maintaining temperatures of between 500 and 600 oC. Water and other volatile
materials are vaporized and organic substances are burned in the presence of the
oxygen in air to CO2, H2O and N2. Most minerals are converted to oxides,
sulfates, phosphates, chlorides or silicates. Although most minerals have fairly
low volatility at these high temperatures, some are volatile and may be partially
lost, e.g., iron, lead and mercury. If an analysis is being carried out to determine
the concentration of one of these substances then it is advisable to use an
alternative ashing method that uses lower temperatures.
The food sample is weighed before and after ashing to determine the
concentration of ash present. The ash content can be expressed on either
a dry or wet basis.
% ASH( dry basis)=Mash/MdryX100
%ASH(wet basis)=Mash/MwetX100
where MASH refers to the mass of the ashed sample, and MDRY and MASH refer to
the original masses of the dried and wet samples.
There are a number of different types of crucible available for ashing food
samples, including quartz, Pyrex, porcelain, steel and platinum. Selection of an
appropriate crucible depends on the sample being analyzed and the furnace
temperature used. The most widely used crucibles are made from porcelain
because it is relatively inexpensive to purchase, can be used up to high
temperatures (< 1200oC) and are easy to clean. Porcelain crucibles are resistant to
acids but can be corroded by alkaline samples, and therefore different types of
crucible should be used to analyze this type of sample. In addition, porcelain
crucibles are prone to cracking if they experience rapid temperature changes. A
number of dry ashing methods have been officially recognized for the
determination of the ash content of various foods (AOAC Official Methods of
Analysis). Typically, a sample is held at 500-600 oC for 24 hours.
Advantages:
Safe, few reagents are required, many samples can be analyzed simultaneously,
not labor intensive, and ash can be analyzed for specific mineral content.
Disadvantages:
Long time required (12-24 hours), muffle furnaces are quite costly to run due to
electrical costs, loss of volatile minerals at high temperatures, e.g., Cu, Fe, Pb,
Hg, Ni, Zn.
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