This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles

for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

Designation: E223 − 25

Standard Test Methods for

Analysis of Sulfuric Acid1
This standard is issued under the fixed designation E223; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the U.S. Department of Defense.

1. Scope* 2. Referenced Documents

1.1 These test methods cover the analysis of sulfuric acid. 2.1 ASTM Standards:2
1.2 The following applies for the purposes of determining D1193 Specification for Reagent Water
the conformance of the test results using this test method to D6809 Guide for Quality Control and Quality Assurance
applicable specifications, results shall be rounded off in accor- Procedures for Aromatic Hydrocarbons and Related Ma-
dance with the rounding-off method of Practice E29. terials
E1 Specification for ASTM Liquid-in-Glass Thermometers
1.3 The values stated in SI units are to be regarded as E29 Practice for Using Significant Digits in Test Data to
standard. The values given in parentheses are for information Determine Conformance with Specifications
only. E60 Practice for Analysis of Metals, Ores, and Related
1.4 The analytical procedures appear in the following order: Materials by Spectrophotometry
Sections E100 Specification for ASTM Hydrometers
Total Acidity 8 to 16 E180 Practice for Determining the Precision of ASTM
Baumé Gravity 17 to 26 Methods for Analysis and Testing of Industrial and Spe-
Nonvolatile Matter 27 to 33
Iron 34 to 43 cialty Chemicals (Withdrawn 2009)3
Sulfur Dioxide 44 to 51 E200 Practice for Preparation, Standardization, and Storage
Arsenic 52 to 61
of Standard and Reagent Solutions for Chemical Analysis
1.5 This standard does not purport to address all of the E300 Practice for Sampling Industrial Chemicals
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro- 3. Significance and Use
priate safety, health, and environmental practices and deter-
mine the applicability of regulatory limitations prior to use. 3.1 These test methods provide for the classification of
Consult current OSHA regulations, suppliers’ Safety Data various grades of sulfuric acid and for the determination of
Sheets, and local regulations for all materials used in this various impurities. Acid strength and impurity levels are
specification. Specific hazards statements are given in Section important factors in many uses of sulfuric acid.
5.
1.6 This international standard was developed in accor- 4. Purity of Reagents
dance with internationally recognized principles on standard- 4.1 Purity of Reagents—Reagent grade chemicals shall be
ization established in the Decision on Principles for the used in all tests. Unless otherwise indicated, it is intended that
Development of International Standards, Guides and Recom- all reagents shall conform to the specifications of the Commit-
mendations issued by the World Trade Organization Technical tee on Analytical Reagents of the American Chemical Society,
Barriers to Trade (TBT) Committee.

1 2
These test methods are under the jurisdiction of ASTM Committee D16 on For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Aromatic, Industrial, Specialty and Related Chemicals and are the direct responsi- contact ASTM Customer Service at www.astm.org/contact. For Annual Book of
bility of Subcommittee D16.10 on Acids. ASTM Standards volume information, refer to the standard’s Document Summary
Current edition approved Feb. 1, 2025. Published February 2025. Originally page on the ASTM website.
approved in 1965. Last previous edition approved in 2023 as E223 – 23ɛ1. DOI: 3
The last approved version of this historical standard is referenced on
10.1520/E0223-25. www.astm.org.

*A Summary of Changes section appears at the end of this standard

Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States

&RS\ULJKWE\$670,QW O DOOULJKWVUHVHUYHG 7XH-XQ87& 1

'RZQORDGHGSULQWHGE\
OXLVULYDVJDUILDV ,QWHUWHN7HVWLQJ6HUYLFHV1$ SXUVXDQWWR/LFHQVH$JUHHPHQW1RIXUWKHUUHSURGXFWLRQVDXWKRUL]HG
 E223 − 25
where such specifications are available.4 Other grades may be 9. Summary of Test Method
used, provided it is first ascertained that the reagent is of 9.1 A weighed sample of acid is diluted in water and titrated
sufficiently high purity to permit its use without lessening the with standardized 0.5 meq/mL(N) sodium hydroxide solution,
accuracy of the determination. using phenolphthalein as the indicator.
4.2 Purity of Water—Unless otherwise indicated, references
to water shall be understood to mean Type I or Type II reagent 10. Interferences
water conforming to Specification D1193. 10.1 Acids other than sulfuric and compounds that consume
sodium hydroxide will affect the accuracy of this test method.
5. Hazards
5.1 Consult current OSHA regulations, suppliers’ Safety 11. Apparatus
5
Data Sheets, and local regulations for all materials used in this 11.1 Dely Tube (Fig. 1) or Snake Tube (Fig. 2).
test method. Use of safety goggles and gloves highly recom-
mended.
5.2 Sulfuric acid is a strong corrosive acid and is dangerous
if improperly handled. Avoid any skin or eye contact.
5.3 Clean up all spills immediately by covering the spill
with vermiculite or some other inert absorbent material and
sweeping into a pan. Dispose of the absorbent by flooding with
water and discarding in a suitable container. Flush the area with
water.

6. Photometers and Photometric Practice

6.1 Photometers and the photometric practice used in these
test methods shall conform to Practice E60.

7. Sampling
7.1 Sample sulfuric acid in accordance with the appropriate
sections of Practice E300 for simple liquids.
7.2 The sample to be analyzed shall be considered to be that
sample in a single bottle submitted to the analytical laboratory.
7.3 The size of the sample shall be sufficient to perform all
analyses without the reuse of any portion of the sample.
TOTAL ACIDITY

8. Scope
FIG. 1 Dely Tube
8.1 This test method covers the determination of the total
acidity of 75 % to 99 % mass (m/m) sulfuric acid. Two test
methods are given for weighing the sample, namely, the Dely 11.2 Buret, 100 mL, Class A, bulb-type.
tube and the snake tube test methods.
12. Reagents
12.1 Phenolphthalein Indicator Solution (10 g/L)—Dissolve
4
1 g of phenolphthalein in 100 mL of ethanol (95 %), methanol,
ACS Reagent Chemicals, Specifications and Procedures for Reagents and
Standard-Grade Reference Materials, American Chemical Society, Washington,
or isopropanol.6
DC. For suggestions on the testing of reagents not listed by the American Chemical 12.2 Sodium Hydroxide, Standard Solution (0.5 meq/
Society, see Analar Standards for Laboratory Chemicals, BDH Ltd., Poole, Dorset,
U.K., and the United States Pharmacopeia and National Formulary, U.S. Pharma-
mL(N)—See Practice E200.
copeial Convention, Inc. (USPC), Rockville, MD.
13. Procedure
TABLE 1 Sample Size for Total Acidity 13.1 Dely Tube Test Method—Invert the sample bottle
H2SO4, % mass (m/m) Sample Size, g several times. (Hold the stopper in tight.) Insert the long arm of
98 1.9 to 2.2
94 2.0 to 2.3
5
90 2.1 to 2.4 The sole source of supply of the Suitable Dely and snake tubes known to the
85 2.2 to 2.6 committee at this time is Corning Glass Works, Corning, NY. If you are aware of
80 2.3 to 2.7 alternative suppliers, please provide this information to ASTM International
77 2.4 to 2.8 Headquarters. Your comments will receive careful consideration at a meeting of the
75 2.5 to 2.9 responsible technical committee,1 which you may attend.
6
This reagent is also described in Practice E200.

&RS\ULJKWE\$670,QW O DOOULJKWVUHVHUYHG 7XH-XQ87& 2

'RZQORDGHGSULQWHGE\
OXLVULYDVJDUILDV ,QWHUWHN7HVWLQJ6HUYLFHV1$ SXUVXDQWWR/LFHQVH$JUHHPHQW1RIXUWKHUUHSURGXFWLRQVDXWKRUL]HG
 E223 − 25
indicator solution. Record the temperature of the 0.5 meq/
mL(N) NaOH solution, and then titrate the sample to a pink
end point. Record the titration to the nearest 0.02 mL.
NOTE 4—Do not introduce the water into the snake tube too rapidly, as
this will cause spattering.

14. Calculation
14.1 If necessary, correct the buret reading for calibration
errors and record the volume of titrant as V and the temperature
as t.
14.2 Correct the normality of the sodium hydroxide stan-
FIG. 2 Snake Tube dard solution for any difference in temperature between time of
standardization and time of use according to the following
equation:
a dry, weighed Dely tube and withdraw by suction a convenient N 5 N s 10.00014 ~ s 2 t ! (1)
size sample depending upon the acid strength as given in Table
1 (Note 1). Invert the Dely tube and wipe the acid from the where:
long arm with disposable tissue several layers thick. Discard N = normality meq/mL(N) of NaOH solution at temperature
the tissue immediately to avoid burning the fingers. Reweigh to t during use,
the nearest 0.0001 g and record the weight of the sample. Ns = normality meq/mL(N) of NaOH solution at temperature
Incline the tube so that the acid runs back nearly to the bend of s during standardization,
the short arm. Attach the short arm to an elevated water s = temperature of NaOH solution during standardization,
reservoir by means of a rubber tube closed near the lower end and
with a pinch clamp. Insert the long arm of the Dely tube into t = temperature of NaOH solution during analysis.
400 mL glass beaker containing approximately 100 mL of 14.3 Calculate the total acidity as % mass (m/m) of sulfuric
water. Open the pinch clamp and flush the sample into the acid as follows:
beaker. Continue the flow of water until all acid is washed from
~ VN × 0.04904!
the Dely Tube (Note 2 and Note 3). Wash the long end of the Sulfuric acid, % mass ~ m/m ! 5 × 100 (2)
W
Dely tube, collecting the washings in the beaker. Add 3 to 5
drops of phenolphthalein indicator solution. Record the tem- where:
perature of the 0.5 meq/mL(N) NaOH solution, and then titrate V = corrected millilitre of NaOH solution required for
the sample to a pink end point. Record the titration to the titration of the sample,
nearest 0.02 mL. N = meq/mL(N) normality of the NaOH solution, and
NOTE 1—The Dely tube can be marked at points equivalent to weights
W = grams of sample used.
given in Table 1.
NOTE 2—The presence of acid in the Dely tube may be detected by 15. Report
coloring the water in the reservoir with phenolphthalein indicator and the
minimum amount of dilute NaOH solution that will produce a slight pink. 15.1 Report the % mass (m/m) of sulfuric acid to the nearest
The water flowing through the tube is dicolorized as long as acid is 0.01 % mass(m/m).
present, and the appearance of a pink color indicates the absence of acid.
NOTE 3—The acid and water are separated by a bubble of air.
16. Precision and Bias
13.2 Snake Tube Test Method—Invert the sample bottle
several times. (Hold the stopper in tight). Insert the capillary 16.1 The following criteria should be used for judging the
end of a dry, weighed snake tube and withdraw by suction a acceptability of results (see Note 5):
convenient size sample depending upon the acid strength as 16.1.1 Repeatability (Single Analyst)—The standard devia-
given in Table 1. Invert the tube so that the double bend is in tion for a single determination has been estimated to be
a horizontal position. Wipe the acid from the capillary with 0.069 % mass (m/m) absolute at 56 df. The 95 % limit for the
disposable tissue several layers thick. Discard the tissue difference between two such runs is 0.19 % mass (m/m)
immediately to avoid burning the fingers. Reweigh to the absolute.
nearest 0.0001 g and record the weight of the sample. Sub- 16.1.2 Laboratory Precision (Within-Laboratory, Between-
merge the capillary of the tube in approximately 100 mL of Days Variability—The standard deviation of results (each the
water contained in the 400 mL beaker. Force the weighed average of duplicates), obtained by the same analyst on
sample from the tube by a stream of water from a wash bottle different days, has been estimated to be 0.104 % mass (m/m)
by placing the delivery tip in the exposed end of the snake tube absolute at 28 df. The 95 % limit for the difference between
(Note 4). Wash the tube with 50 mL to 70 mL of water. two such averages is 0.29 % mass (m/m) absolute.
Remove the tube and wash the outside free of acid. Swirl the 16.1.3 Reproducibility (Multilaboratory)—The standard de-
contents of the beaker gently while washing. Accumulate all viation of results (each the average of duplicates), obtained by
washings in the beaker and add 3 to 5 drops of phenolphthalein analysts in different laboratories, has been estimated to be

&RS\ULJKWE\$670,QW O DOOULJKWVUHVHUYHG 7XH-XQ87& 3

'RZQORDGHGSULQWHGE\
OXLVULYDVJDUILDV ,QWHUWHN7HVWLQJ6HUYLFHV1$ SXUVXDQWWR/LFHQVH$JUHHPHQW1RIXUWKHUUHSURGXFWLRQVDXWKRUL]HG
 E223 − 25
0.124 % mass (m/m) absolute at 7 df. The 95 % limit for the 21.3 Cylinder, Hydrometer, glass, with or without lip, diam-
difference between two such averages is 0.35 % mass (m/m) eter 38 mm to 40 mm, height 325 mm to 375 mm.
absolute.
22. Temperature of Test
NOTE 5—These precision estimates are based on an interlaboratory
study of analyses performed in 1963 on three samples containing 22.1 Baumé gravity shall be determined at 15.5 °C 6 0.3 °C
approximately 80 %, 90 %, and 95 % mass (m/m) sulfuric acid. One (60 °F 6 0.5 °F).
analyst in each of ten laboratories performed duplicate determinations and
repeated one day later, for a total of 120 determinations.7 Practice E180 23. Procedure
was used in developing these precision estimates. 23.1 Rinse a clean hydrometer cylinder with the sample to
16.2 Since there is no accepted reference material for be tested, add the sample, and adjust the temperature to 15.5 °C
determining the bias for measuring the total acidity of sulfuric 6 0.3 °C (60 °F 6 0.5 °F). Place the cylinder in a vertical
acid, the bias of this test method has not been determined. position in a location free of air currents. Insert the hydrometer
in the sample. Push it down about 3 mm below the level at
BAUMÉ GRAVITY which it will float and release it. Read the hydrometer when it
has come to rest, floating freely, and the temperature is 15.5 °C
17. Scope
(60 °F). The correct reading is that point on the hydrometer
17.1 This test method covers the determination of the scale at which the surface of the liquid cuts the scale.
Baumé gravity of concentrated sulfuric acid by means of a Determine this point by placing the eye slightly below the level
glass hydrometer in the range from 57° Baumé to 66.2° of the liquid and slowly raising it until the surface, first seen as
Baumé. The Baumé gravity is determined at 15.5 °C (60 °F). a distorted ellipse, appears to become a straight line cutting the
This test method is not applicable to readings above 66.2 hydrometer scale. Record as Baumé gravity.
Baumé gravity units.
24. Calculation
18. Definition 24.1 Calculate the specific gravity for later calculations in
18.1 Baumé Gravity—a unit of density based on specific accordance with the following equation:
gravity and defined by the following equation: 145
sp gr 5 (5)
Baumé gravity 5 145 2 @ 145/sp gr# at 15.5/15.5°C ~ 60/60°F ! (3) 145 2 Bé

19. Summary of Test Method 25. Report

19.1 A sample of sulfuric acid is placed in a hydrometer 25.1 Report the Baumé gravity to the nearest 0.01 unit.
cylinder and when the temperature is constant, the Baumé 26. Precision and Bias
gravity is read from the glass hydrometer.
26.1 The following criteria should be used for judging the
20. Significance and Use acceptability of results (see Note 6):
26.1.1 Repeatability (Single Analyst)—The standard devia-
20.1 The Baumé gravity is used to classify various grades of
tion for a single determination has been estimated to be 0.018
sulfuric acid. This test method is not applicable for accurate
unit absolute at 48 df. The 95 % limit for the difference
determinations of the concentration of sulfuric acid.
between two such runs is 0.05 unit absolute.
21. Apparatus 26.1.2 Laboratory Precision (Within-Laboratory, Between-
Days Variability)—The standard deviation of results (each the
21.1 Hydrometer,8streamline or torpedo design, precision average of duplicates), obtained by the same analyst on
grade for liquids heavier than water in ranges from 57° Bé to different days, has been estimated to be 0.016 unit absolute at
62° Bé and 63° Bé to 67° Bé. The total length shall be 24 df. The 95 % limit for the difference between two such
approximately 305 mm (12 in.) divided to 0.05° Bé over a averages is 0.045 unit absolute.
152 mm (6 in.) (approximate) scale and standardized at 26.1.3 Reproducibility (Multilaboratory)—The standard de-
15.5 °C ⁄15.5 °C (60 °F ⁄60 °F) with a tolerance of 0.05° Bé viation of results (each the average of duplicates), obtained by
throughout. The modulus is as follows: analysts in different laboratories, has been estimated to be
Bé 5 145 2 @ 145/sp gr# at 15.5/15.5°C ~ 60/60°F ! (4) 0.063 unit absolute at 7 df. The 95 % limit for the difference
Each of the hydrometers shall show on the scale the between two such averages is 0.18 unit absolute.
modulus. NOTE 6—These precision estimates are based on an interlaboratory
study of analyses performed in 1963 on three samples having Baumé
21.2 Thermometer, having a range from − 2 °C to + 80 °C gravities of approximately 61, 65, and 66 units. One analyst in each of
(30 °F to 180 °F) and conforming to the requirements for nine laboratories performed duplicate determinations and repeated one
Thermometer 15C (15F) as prescribed in Specification E1. day later, for a total of 104 determinations.7 Practice E180 was used in
developing these precision estimates.

7
26.2 Since there is no accepted reference material for
Supporting data have been filed at ASTM International Headquarters and may
be obtained by requesting Research Report RR:E15-1047. Contact ASTM Customer
determining the bias for measuring the Baumé gravity of
Service at www.astm.org/contact. sulfuric acid, the bias of this test method has not been
8
See Specification E100. determined.

&RS\ULJKWE\$670,QW O DOOULJKWVUHVHUYHG 7XH-XQ87& 4

'RZQORDGHGSULQWHGE\
OXLVULYDVJDUILDV ,QWHUWHN7HVWLQJ6HUYLFHV1$ SXUVXDQWWR/LFHQVH$JUHHPHQW1RIXUWKHUUHSURGXFWLRQVDXWKRUL]HG
 E223 − 25
NONVOLATILE MATTER 31. Calculation

27. Scope 31.1 Calculate the % mass (m/m) of nonvolatile matter as

follows (Note 11):
27.1 This test method covers the gravimetric determination
R2D
of nonvolatile matter in sulfuric acid. The lower limit of Nonvolatile matter, % mass ~ m/m ! 5 × 100 (6)
W
determination of nonvolatile matter is 0.001 % mass (m/m).
where:
28. Summary of Test Method R = weight of evaporating dish and residue, g,
28.1 A weighed sample of acid is evaporated, ignited, and D = weight of evaporating dish, g, and
the residue weighed. W = sample used, g.
NOTE 11—If this value is less than 0.0010 % mass (m/m), report as less
29. Apparatus than 0.0010 % mass (m/m).
29.1 Evaporating Dish, platinum or high-silica glass,
32. Report
150 mL.
29.2 Muffle Furnace, maintained at 800 °C 6 25 °C 32.1 Report the percentage of nonvolatile matter to the
(1472 °F 6 45 °F). nearest 0.0001 % mass (m/m).
29.3 Crucible Tongs. 33. Precision and Bias
30. Procedure 33.1 The following criteria should be used for judging the
30.1 Clean a platinum or a high-silica glass dish (Note 7 and acceptability of results (see Note 12):
Note 8) and ignite in a muffle furnace at 800 °C 6 25 °C 33.1.1 Repeatability (Single Analyst)—The standard devia-
(1472 °F 6 45 °F) for at least 10 min. Cool in a desiccator to tion for a single determination has been estimated to be the
room temperature and weigh the dish to the nearest 0.1 mg value in Table 2 at the indicated degrees of freedom. The 95 %
(Note 9). limit for the difference between two such runs is given in Table
2.
NOTE 7—New platinum or high-silica glass dishes should be boiled in
HCl (1 + 1) for 10 min, washed, and ignited in the muffle furnace for at 33.1.2 Laboratory Precision (Within-Laboratory, Between-
least 1 h before their first use. Days Variability)—The standard deviation of results (each the
NOTE 8—High-silica glass dishes should be used only for low nonvola- average of duplicates), obtained by the same analyst on
tile material. The residue remaining from samples containing large different days, has been estimated to be the value in Table 2 at
amounts of nonvolatile matter may fuse into the dish. the indicated degrees of freedom. The 95 % limit for the
NOTE 9—High-silica glass dishes should be allowed to cool at least
45 min and platinum dishes at least 20 min before weighing. difference between two such averages is given in Table 2.
30.2 Mix the sample by inverting the sample bottle repeat- 33.1.3 Reproducibility (Multilaboratory)—The standard de-
edly until all solids are in suspension. viation of results (each the average of duplicates), obtained by
analysts in different laboratories, has been estimated to be the
NOTE 10—It is important that the sample be well mixed and that all value given in Table 2 at the indicated degrees of freedom. The
solids are in homogeneous suspension so that a representative sample can 95 % limit for the difference between two such averages is
be obtained.
given in Table 2.
30.3 Transfer a weighed sample containing a minimum of
50 g, weighed to the nearest 0.1 g, or a weighed sample of NOTE 12—These precision estimates are based on an interlaboratory
sufficient size to yield not less than 1 mg of residue, to the study of analyses performed in 1963 to 1964 on five samples containing
approximately 0.003 %, 0.005 %, 0.010 %, 0.014 %, 0.024 %, and
evaporating dish and evaporate to dryness over a burner or hot 0.048 % mass (m/m) nonvolatile matter. One analyst in each of eight to
plate in a hood. After evaporation, ignite the sample in the ten laboratories performed duplicate determinations and repeated one day
muffle furnace for 10 min. Use crucible tongs in handling the later.7 Practice E180 was used in developing these precision estimates.
evaporating dish at all times. 33.2 Since there is no accepted reference material for
30.4 Allow the dish to cool to room temperature in a determining the bias for measuring the nonvolatile matter of
desiccator and rapidly weigh the sample dish to the nearest sulfuric acid, the bias of this test method has not been
0.1 mg. determined.

TABLE 2 Nonvolatile Matter Precision Values

Repeatability Laboratory Precision Reproducibility
NVM,% mass
(m/m) Standard Degrees of Standard Degrees of Standard Degrees of
95 % Range 95 % Range 95 % Range
Deviation Freedom Deviation Freedom Deviation Freedom
0.003 0.0004 22 0.0010 0.0004 11 0.0010 0.0015 10 0.0040
0.004 0.0008 16 0.0023 0.0007 8 0.0019 0.0013 7 0.0036
0.01 to 0.024 0.0015 54 0.0042 0.0009 27 0.0024 0.0013 7 0.0036
0.048 0.0009 20 0.0025 0.0013 10 0.0036 0.0046 9 0.0130

&RS\ULJKWE\$670,QW O DOOULJKWVUHVHUYHG 7XH-XQ87& 5

'RZQORDGHGSULQWHGE\
OXLVULYDVJDUILDV ,QWHUWHN7HVWLQJ6HUYLFHV1$ SXUVXDQWWR/LFHQVH$JUHHPHQW1RIXUWKHUUHSURGXFWLRQVDXWKRUL]HG
 E223 − 25
IRON each flash add the following reagents in order, mixing after
addition of each: 20 mL of water, 1 mL of hydroxylamine
34. Scope hydrochloride solution, 5 mL of 1,10-phenanthroline solution,
34.1 This test method describes the determination of iron in and NH4OH (1 + 1) as required to bring the pH to 3.5 to 4.0
sulfuric acid. The lower limit of determination of iron is (just alkaline to Congo red paper). Add 5 mL of ammonium
0.0001 % mass (m/m). acetate solution, dilute to the mark with water, mix thoroughly,
and allow to stand approximately 15 min.
35. Summary of Test Method
39.2 Measure the absorbances of the solutions using a
35.1 The iron is reduced and determined colorimetrically
photometer with a wavelength setting of 510 nm or a filter
with 1,10-phenanthroline (ortho-phenanthroline), which forms
photometer equipped with a filter in the range from 500 nm to
an orange-red complex with ferrous iron. The intensity of the
525 nm, adjusting the photometer to read zero absorbance for
color so formed is measured in a photometer calibrated with
the reagent blank.
standard iron solutions.
39.3 Plot on coordinate paper the absorbances of the cali-
36. Interferences bration solutions against milligrams of iron present per 100 mL
36.1 It is beyond the scope of this test method to describe of solution.
procedures for overcoming all possible interferences that may
be encountered. Chromium interferes if it is present in suffi- 40. Procedure
cient quantity for the color of chromic ion to have a masking 40.1 Mix the sample by inverting the sample bottle until all
effect. Copper, antimony, cobalt, mercury (I), and tin (II, IV) solids are in suspension (Note 10).
interfere in concentrations of 10 µg ⁄g to 50 µg/g (ppm).
40.2 Insert a 70 mm stem funnel in a 100 mL volumetric
Cadmium, mercury (II), zinc, and nickel may interfere, but can
flask and add 50 mL of water (Note 14). Remove the funnel
be overcome by the use of excess 1,10-phenanthroline reagent.
and slowly add, with continual swirling of the contents of the
37. Apparatus flask, 1 g of sample weighed by difference to the nearest
0.001 g. Wash down the neck of the flask with approximately
37.1 Photometer—Any photoelectric spectrophotometer or
5 mL of water.
filter photometer that will measure the absorbance of the
solutions in the wavelength range from 500 nm to 525 nm. NOTE 14—This is done to keep the neck of the flask dry and prevent
spitting or spattering on introducing the sample.
37.2 Absorption Cells, 2 cm light path.
40.3 Add to the flask the following reagents in order, mixing
NOTE 13—This procedure has been written for a cell having a 2 cm light after the addition of each: 1 mL of hydroxylamine hydrochlo-
path. Cells having other dimensions may be used, provided suitable
adjustments can be made in the amounts of sample and reagents used.
ride solution, 5 mL of 1,10-phenanthroline solution, and
NH4OH (1 + 1) as required to bring the pH of the solution to
38. Reagents 3.5 to 4.0 (just alkaline to Congo red paper). Add 5 mL of
38.1 Ammonium Acetate–Acetic Acid Solution—Dissolve ammonium acetate solution, dilute to the mark with water, mix
100 g of ammonium acetate (CH3COONH4) in about 600 mL thoroughly, and allow to stand approximately 15 min.
of water, filter, add 200 mL of glacial acetic acid to the filtrate, 40.4 Prepare a blank solution using all reagents but omitting
and dilute to 1 L. the sample. Allow to stand about 15 min.
38.2 Ammonium Hydroxide Solution (1 + 1)—Dilute to 40.5 Determine the absorbance of the sample at the same
500 mL of ammonium hydroxide (NH4OH) with 500 mL of wavelength used for the calibration curve, blanking the instru-
water, and mix.6 ment at zero absorbance with the blank solution. Determine
38.3 Congo Red Paper. from the calibration curve the milligrams of iron that corre-
spond to the observed absorbance of the sample.
38.4 Hydroxylamine Hydrochloride Solution (100 g/L)—
Dissolve 100 g of hydroxylamine hydrochloride (NH2OH·HCl) NOTE 15—If the color obtained is too intense to fall within the range of
in about 600 mL of water, filter, and dilute to 1 L.6 the calibration curve, repeat with a smaller sample.
NOTE 16—If the color obtained is less than that obtained with 0.01 mg
38.5 Iron, Standard Solution (1 mL = 0.01 mg Fe)9—See of iron, repeat as follows: Transfer 10 g of sample, weighed by difference
Practice E200. to the nearest 0.01 g, to a 50 mL beaker and evaporate almost to dryness
over a burner or hotplate in a hood. Cool. Add 10 mL of water and 2 mL
38.6 1,10-Phenanthroline (o-Phenanthroline) Solution of HCl (sp gr 1.19) and heat to dissolve any solids. Transfer the solution
(3 g ⁄L)—Dissolve 3 g of ortho-phenanthroline monohydrate in to a 100 mL volumetric flask with a minimum amount of water and
500 mL of water, add 1 mL of hydrochloric acid (HCl), mix, proceed in accordance with 40.3 starting with the addition of 1 mL of
hydroxylamine hydrochloride solution.
filter, and dilute to 1 L.6
39. Calibration 41. Calculation
39.1 To a series of 100 mL volumetric flasks, pipet 0 mL, 41.1 Calculate the % mass (m/m) of iron as follows (Note
2 mL, 4 mL, 8 mL, and 10 mL of standard iron solution. To 17):
M
Iron, mass % ~ m/m ! 5 × 100 (7)
9
This reagent is used for calibrating purposes only. W × 1000

&RS\ULJKWE\$670,QW O DOOULJKWVUHVHUYHG 7XH-XQ87& 6

'RZQORDGHGSULQWHGE\
OXLVULYDVJDUILDV ,QWHUWHN7HVWLQJ6HUYLFHV1$ SXUVXDQWWR/LFHQVH$JUHHPHQW1RIXUWKHUUHSURGXFWLRQVDXWKRUL]HG
 E223 − 25
where: SULFUR DIOXIDE
M = iron, found from calibration curve, mg, and
W = sample used, g. 44. Scope
NOTE 17—If this value is less than 0.0001 % mass (m/m), report as less 44.1 This test method covers the determination of free
than 0.0001 % mass (m/m). sulfur dioxide dissolved in sulfuric acid. The lower limit of
determination of sulfur dioxide is 0.002 % mass (m/m).
42. Report
45. Summary of Test Method
42.1 Report the % mass (m/m) of iron to the nearest
45.1 The sulfur dioxide is swept out of the sample of
0.0001 % mass (m/m).
sulfuric acid by means of a current of nitrogen gas. The
evolved sulfur dioxide is absorbed in an alkaline solution,
43. Precision and Bias
treated with an excess of iodate-iodide solution and the excess
43.1 The following criteria should be used for judging the is titrated with sodium thiosulfate.
acceptability of results (see Note 18):
46. Apparatus
43.1.1 Repeatability (Single Analyst)—The standard devia-
tion for a single determination has been estimated to be 46.1 Evolution and Absorption Train, consisting of:
0.00018 % mass (m/m) absolute at 52 df. The 95 % limit for 46.1.1 Source of Pure Nitrogen Gas, connected to
the difference between two such runs is 0.0005 % mass (m/m) 46.1.2 Gas-Washing Bottle, 125 mL, connected as a safety
absolute. trap to prevent acid suck-back, connected to
43.1.2 Laboratory Precision (Within-Laboratory, Between- 46.1.3 Gas-Washing Bottle, 125 mL, with fritted glass disk
on the inlet tube, connected to
Days Variability)—The standard deviation of results (each the
46.1.4 Gas-Washing Bottle, 250 mL, with fritted glass disk
average of duplicates), obtained by the same analyst on
on the inlet tube.
different days, has been estimated to be 0.00021 % mass (m/m)
absolute at 26 df. The 95 % limit for the difference between 47. Reagents
two such averages is 0.0006 % mass (m/m) absolute.
47.1 Potassium Iodate-Potassium Iodide Solution (approxi-
43.1.3 Reproducibility (Multilaboratory)—The standard de- mately 0.1 meq/mL (N))—Dissolve 4 g of potassium iodate
viation of results (each the average of duplicates), obtained by (KIO3) and 100 g of potassium iodide (KI) in water and dilute
analysts in different laboratories, has been estimated to be to 1 L with water.
0.00034 % mass (m/m) absolute at 6 df. The 95 % limit for the
difference between two such averages is 0.0009 % mass (m/m) 47.2 Sodium Hydroxide Solution (4 g/L)—Dissolve 4 g of
absolute. sodium hydroxide (NaOH) in water and dilute to 1 L.6
47.3 Sodium Thiosulfate, Standard Solution (0.1 meq/mL
NOTE 18—These precision estimates are based on an interlaboratory (N))—See Practice E200.
study of analyses performed in 1963 to 1964 on three samples containing
approximately 0.004 %, 0.005 %, and 0.008 % mass (m/m) iron. One 47.4 Sodium Thiosulfate, Standard Solution (0.01 meq/mL
analyst in each of nine laboratories performed duplicate determinations (N))—Pipet 100 mL of 0.1 meq/mL (N) sodium thiosulfate
and repeated one day later, for a total of 108 determinations.7 Practice
(Na2S2O3) solution into a 1 L volumetric flask, dilute to
E180 was used in developing these precision estimates.
One sample, containing approximately 0.0003 % mass (m/m) iron and volume with water, and mix. The normality is exactly one tenth
analyzed by one analyst in each of eight laboratories for a total of 32 that of the 0.1 N solution.
determinations, gave the following precision data:
47.5 Starch Indicator Solution (10 g/L)—Mix 1 g of soluble
Repeatability (Single Analyst)—The standard deviation for a single
determination has been estimated to be 0.000041 % mass (m/m) absolute starch with 5 mg of red mercuric iodide (HgI2) and enough
at 16 df. The 95 % limit for the difference between two such runs is cold water to make a thin paste, and pour slowly, with constant
0.0001 % mass (m/m) absolute. stirring, into 100 mL of boiling water. Boil the mixture while
Laboratory Precision (Within-Laboratory, Between-Days stirring until a thin, translucent fluid is obtained. Cool before
Variability)—The standard deviation of results (each the average of
use.6
duplicates), obtained by the same analyst on different days, has been
estimated to be 0.000051 % mass (m/m) absolute at 8 df. The 95 % limit 47.6 Sulfuric Acid (1 + 5) —Mix carefully while stirring, 1
for the difference between two such averages is 0.0001 % mass (m/m) volume of concentrated sulfuric acid (H2SO4, sp gr 1.84) with
absolute.
5 volumes of water.
Reproducibility (Multilaboratory)—The standard deviation of results
(each the average of duplicates), obtained by analysts in different
laboratories, has been estimated to be 0.00014 % mass (m/m) absolute at
48. Procedure
7 df. The 95 % limit for the difference between two such averages is 48.1 Flush out the safety bottle with nitrogen.
0.0004 % mass (m/m) absolute.
48.2 From a graduated cylinder, transfer about 50 mL of the
43.1.4 Above 0.01 % mass (m/m) iron, the precision is poor sample into the 125 mL gas-washing bottle and connect to the
because of difficulty in sampling. safety bottle. Note the millilitres of sample used, W.
43.2 Since there is no accepted reference material for 48.3 Place about 100 mL of the NaOH solution in 250 mL
determining the bias for measuring the iron content of sulfuric gas-washing bottle and connect to the 125 mL gas-washing
acid, the bias of this test method has not been determined. bottle.

&RS\ULJKWE\$670,QW O DOOULJKWVUHVHUYHG 7XH-XQ87& 7

'RZQORDGHGSULQWHGE\
OXLVULYDVJDUILDV ,QWHUWHN7HVWLQJ6HUYLFHV1$ SXUVXDQWWR/LFHQVH$JUHHPHQW1RIXUWKHUUHSURGXFWLRQVDXWKRUL]HG
 E223 − 25
48.4 Pass nitrogen gas through the apparatus at about 20 L/h NOTE 20—These precision estimates are based on an interlaboratory
for 3 h. study of analyses performed in 1967 on three samples containing
approximately 0.004, 0.008, and 0.016 % mass (m/m) sulfur dioxide. One
48.5 Disconnect the bottle containing the NaOH solution analyst in each of seven laboratories performed duplicate determinations
and turn off the nitrogen flow. Rinse the bubbler tube with and repeated one day later, for a total of 84 determinations.7 Practice E180
water into the bottle, pipet 5 mL of the KIO3-KI solution into was used in developing these precision estimates.
the bottle, and mix. 51.2 Since there is no accepted reference material for
48.6 Add 5 mL of H2SO4 (1 + 5) and 2 mL of the starch determining the bias for measuring the sulfur dioxide content
indicator solution and titrate with the 0.01 meq/mL (N) of sulfuric acid, the bias of this test method has not been
Na2S2O3 solution until the blue color is discharged. Record the determined.
volume of Na2S2O3 solution used, A. (If no blue color is ARSENIC
evident, repeat the procedure with 25 mL of sample.)
48.7 Repeat the entire procedure, substituting 50 mL of 52. Scope
water for the sample in the 125 mL gas-washing bottle. Record 52.1 This test method describes the colorimetric determina-
the volume of Na2S2O3 solution used, B. tion of arsenic in sulfuric acid. The lower limit of determina-
48.8 If the back titration of the sample solution requires tion is 0.01 µg/g (ppm) of arsenic.
more than 30 mL of the Na2S2O3 solution repeat both the blank 53. Summary of Test Method
and sample determinations, using only 2 mL of the KIO3-KI
solution. 53.1 The arsenic is reduced to arsine gas, which is absorbed

49. Calculation
49.1 Calculate the % mass (m/m) of sulfur dioxide as
follows (Note 19):
~ B 2 A ! × N × 0.032 × 100
Sulfur dioxide, % mass ~ m/m ! 5 (8)
W × sp gr

where:
B = Na2S2O3 solution required for the titration of the blank
solution, mL,
A = Na2S2O3 solution required for the titration of the
sample solution, mL,
N = normality meq/mL (N) of the Na2S2O3 solution, and
W = sample used, mL.
NOTE 19—If this value is less than 0.002 % mass (m/m), report as less
than 0.002 % mass (m/m)%.

50. Report
50.1 Report the % mass (m/m) of sulfur dioxide to the
nearest 0.001 % mass (m/m).
51. Precision and Bias
51.1 The following criteria should be used for judging the
acceptability of results (see Note 20):
51.1.1 Repeatability (Single Analyst)—The coefficient of
variation for a single determination has been estimated to be
10.1 % relative at 42 df. The 95 % limit for the difference
between two such runs is 28 % mass (m/m) relative.
51.1.2 Laboratory Precision (Within-Laboratory, Between-
Days Variability)—The coefficient of variation of results (each
the average of duplicates), obtained by the same analyst on
different days, has been estimated to be 7.45 % mass (m/m)
relative at 21 df. The 95 % limit for the difference between two
such averages is 21 % mass (m/m) relative.
51.1.3 Reproducibility (Multilaboratory)—The coefficient A—Generator, 125 mL Erlenmeyer
B—Standard-taper joint, 24/40
of variation of results (each the average of duplicates), ob- C—Scrubber
tained by analysts in different laboratories, has been estimated D—Ball joint, 12/2
E—Absorber, 12 mL heavy-wall, centrifuge tube with extended arm capillary
to be 15.7 % mass (m/m) relative at 6 df. The 95 % limit for the connection, 2 mm inside diameter
difference between two such averages is 44 % mass (m/m)
relative. FIG. 3 Arsine Generator

&RS\ULJKWE\$670,QW O DOOULJKWVUHVHUYHG 7XH-XQ87& 8

'RZQORDGHGSULQWHGE\
OXLVULYDVJDUILDV ,QWHUWHN7HVWLQJ6HUYLFHV1$ SXUVXDQWWR/LFHQVH$JUHHPHQW1RIXUWKHUUHSURGXFWLRQVDXWKRUL]HG
 E223 − 25
in a pyridine solution of silver diethyldithiocarbamate, forming 56.11 Stannous Chloride Solution (400 g/L)—Dissolve 40 g
a red-colored complex, the intensity of which is measured on a of stannous chloride dihydrate (SnCl2·2H2O) in a mixture of
photometer. 25 mL of water and 75 mL of HCl (sp gr 1.19).
56.12 Zinc, 20 mesh.
54. Interference
54.1 Antimony is reduced to stibine which reacts with the 57. Calibration
reagent. The color produced is slightly different from that
57.1 Into a series of the 125 mL generator flasks pipet 0 mL,
produced by arsine.
1 mL, 3 mL, 5 mL, 10 mL, and 15 mL of standard arsenic
solution (Note 23). Dilute each flask to 35 mL with water. Add
55. Apparatus 5 mL of HCl, 2 mL of KI solution, and 8 drops of SnCl2
55.1 Absorption Cells, 2 cm light path. solution (Note 24). Mix the solutions and allow them to stand
NOTE 21—This procedure has been written for a cell having a 2 cm light for 15 min to ensure complete reduction of the arsenic to the
path. Cells having other dimensions may be used, provided suitable trivalent form.
adjustments can be made in the amounts of sample and reagents used.
57.2 Pack the scrubber tube for each flask with the lead
55.2 Arsine Generator (Fig. 3).10 acetate impregnated glass wool and moisten with 1 drop of lead
55.3 Flasks, volumetric, ground-glass stoppered, 10 mL. acetate solution. Lubricate the standard taper and ball-and-
socket joints with lubricant and assemble the scrubber-absorber
55.4 Photometer—Any photoelectric spectrophotometer or
unit. Do not attach scrubber-absorber unit to the generator
filter photometer that will measure the absorbance of the
flask. Pipet 3 mL of the silver diethyldithiocarbamate solution
solutions in the range from 500 nm to 575 nm.
into each absorber section. By means of a powder funnel,
56. Reagents (Note 22) quickly add 3.0 g of zinc to each flask. Immediately attach the
NOTE 22—All reagents and water used in the determination of arsenic scrubber-absorber unit to the generator flask and let stand for
by this test method should be very low in arsenic, particularly the zinc. If 30 min.
the NaNO3 is high in arsenic, substitute 5 drops of HNO3 (sp gr 1.42) for
the 0.1 g of NaNO3. 57.3 Transfer the solutions from the absorber sections to
9 separate, dry 10 mL volumetric flasks. Rinse out each absorber
56.1 Arsenic, Standard Solution (1 mL = 0.001 mg As) —
section with pyridine and transfer the washings to the same
See Practice E200.
flask. Make to volume with pyridine and mix.
56.2 Hydrochloric Acid (sp gr 1.189)—Concentrated hydro-
chloric acid (HCl). 57.4 Measure the absorbances of the solutions using a
photometer with a wavelength setting of 560 nm or a filter
56.3 Lead Acetate Impregnated Glass Wool—Dissolve photometer equipped with a filter in the range from 500 nm to
100 g of lead acetate trihydrate (Pb(C2H3O2)2·3H2O) in 575 nm, adjusting the photometer to read zero absorbance for
200 mL of water. Saturate glass wool with the solution, remove the reagent blank.
excess solution, and vacuum dry at room temperature. Store the
impregnated wool in a capped bottle. 57.5 Plot on coordinate paper the absorbances of the cali-
bration solutions against milligrams of arsenic present per
56.4 Methyl Red Indicator Solution (5 g/L)—Dissolve 5 g of 10 mL.
methyl red in 1 L of ethanol (95 %).6
NOTE 23—All new glassware must be cleaned with hot concentrated
56.5 Potassium Iodide Solution (100 g/L)—Dissolve 100 g H2SO4, rinsed with water, rinsed with acetone, and dried. If the glassware
of potassium iodide (KI) in about 750 mL of water, filter, and is reserved for arsenic determinations exclusively, the H2SO4 may be
dilute to 1 L.6 omitted in subsequent washings.
NOTE 24—Too great an excess of SnCl2 causes loss of arsenic by
56.6 Pyridine (C5H5N)—This reagent must be water white. reducing it to elemental arsenic.
56.7 Silver Diethyldithiocarbamate—[(C2H5)2·NSCSAg]
Solution (5 g/L of Pyridine)—Dissolve 1 g in 200 mL of 58. Procedure
pyridine. Store in an amber bottle. Prepare fresh monthly. 58.1 From a graduated cylinder, transfer about 50 mL of the
56.8 Sodium Chloride (NaCl). sample to a 100 mL beaker. Record the number of millilitres
56.9 Sodium Hydroxide Solution (100 g/L)—Dissolve 100 g taken, W. Add about 0.1 g of NaNO3 and 0.1 g of NaCl and
of sodium hydroxide (NaOH) in water and dilute to 1 L with evaporate on a hot plate in the hood to almost dryness.
water. 58.2 Wash the sample into a generator flask with small
56.10 Sodium Nitrate (NaNO3). portions of water. Do not exceed 30 mL total volume.
58.3 Add 1 drop of methyl red indicator solution and add
NaOH solution dropwise until the solution is just alkaline
10
The sole source of supply of the apparatus known to the committee at this time (yellow). Dilute to 35 mL with water.
is Fisher Scientific Co. No. 01-405. If you are aware of alternative suppliers, please
58.4 Add 5 mL of HCl, 2 mL of KI solution, and 8 drops of
provide this information to ASTM International Headquarters. Your comments will
receive careful consideration at a meeting of the responsible technical committee,1 SnCl2 solution. Mix the solution and allow it to stand for
which you may attend. 15 min.

&RS\ULJKWE\$670,QW O DOOULJKWVUHVHUYHG 7XH-XQ87& 9

'RZQORDGHGSULQWHGE\
OXLVULYDVJDUILDV ,QWHUWHN7HVWLQJ6HUYLFHV1$ SXUVXDQWWR/LFHQVH$JUHHPHQW1RIXUWKHUUHSURGXFWLRQVDXWKRUL]HG
 E223 − 25
58.5 Pack the scrubber tube for the flask with the lead different days, has been estimated to be the value in Table 3 at
acetate impregnated glass wool and moisten with 1 drop of lead the indicated degrees of freedom. The 95 % limit for the
acetate solution. Lubricate the standard taper and ball-and- difference between two such averages is given in Table 3.
socket joints with lubricant and assemble the scrubber-absorber 61.1.3 Reproducibility (Multilaboratory)—The standard de-
unit. Do not attach scrubber-absorber unit to the generator viation of results (each the average of duplicates), obtained by
flask. Pipet 3 mL of the silver diethyldithiocarbamate solution analysts in different laboratories, has been estimated to be the
into the absorber section. By means of a powder funnel, value in Table 3 at the indicated degrees of freedom. The 95 %
quickly add 3.0 g of zinc to the flask. Immediately attach the limit for the difference between two such averages is given in
scrubber-absorber unit to the generator flask and let stand for Table 3.
30 min.
NOTE 27—These precision estimates are based on an interlaboratory
58.6 Transfer the solution from the absorber section to a dry study of analyses performed in 1967 on two samples containing approxi-
10 mL volumetric flask. Rinse out the absorber section with mately 0.06 µg/g and 0.6 µg/g (ppm) arsenic. One analyst in each of eight
laboratories performed duplicate determinations and repeated one day
pyridine and transfer the washings to the same flask. Make to later, for a total of 32 determinations.7 Practice E180 was used in
volume with pyridine and mix. developing these precision estimates.
58.7 Prepare a blank solution using all reagents but omitting One sample, containing approximately 0.01 µg/g (ppm) arsenic, was
analyzed by one analyst in each of eight laboratories for a total of 32
the sample. determinations. Data produced at this level were erratic because the
58.8 Determine the absorbance of the sample at the same arsenic content was at the limit of sensitivity of this test method.
wavelength used for the calibration curve, blanking the instru- 61.2 Since there is no accepted reference material for
ment at zero percent absorbance with the blank solution. determining the bias for measuring the arsenic content of
Determine from the calibration curve the milligrams of arsenic sulfuric acid, the bias of this test method has not been
that correspond to the observed absorbance. determined.
NOTE 25—If the color obtained is too intense to fall within the range of
the calibration curve, repeat with a smaller sample.
62. Quality Guidelines
62.1 Laboratories shall have a quality control system in
59. Calculation place.
59.1 Calculate the µg/g (ppm) of arsenic as follows (Note 62.1.1 Confirm the performance of the test instrument or
26): test method by analyzing a quality control sample following
M × 1000 the guidelines of standard statistical quality control practices.
Arsenic, µg/g ~ ppm! 5 (9) 62.1.2 A quality control sample is a stable material isolated
W × sp gr
from the production process and representative of the sample
where: being analyzed.
M = arsenic found from calibration curve, mg, and 62.1.3 When QA/QC protocols are already established in
W = sample, mg. the testing facility, these protocols are acceptable when they
NOTE 26—If this value is less than 0.01 µg/g (ppm), report as less than confirm the validity of test results.
0.01 µg/g (ppm). 62.1.4 When there are no QA/QC protocols established in
60. Report the testing facility, use the guidelines described in Guide
D6809 or similar statistical quality control practices.
60.1 Report the µg/g (ppm) of arsenic to the nearest
0.01 µg ⁄g (ppm). 62.2 When a quality program is not possible, use one of the
following statements.
61. Precision and Bias 62.2.1 In the case of pass/fail data, no generally acceptable
61.1 The following criteria should be used for judging the method for determining that this test is under statistical control
acceptability of results (see Note 27): is currently available.
61.1.1 Repeatability (Single Analyst)—The standard devia- 62.2.2 There is no known suitable material available for
tion for a single determination has been estimated to be the determining that this test is under statistical control.
value in Table 3 at the indicated degrees of freedom. The 95 % 62.3 Interlaboratory Testing:
limit for the difference between two such runs is given in Table 62.3.1 A program that includes multiple laboratories ana-
3. lyzing the same samples is strongly encouraged. This program
61.1.2 Laboratory Precision (Within-Laboratory, Between- should allow labs to compare their results with other labora-
Days Variability)—The standard deviation of results (each the tories. This is particularly important when a plant is selling the
average of duplicates), obtained by the same analyst on product to customers or the laboratory is analyzing the product

TABLE 3 Arsenic Precision Values

Repeatability Laboratory Precision Reproducibility
Level, µg/g
Standard Degrees of Standard Degrees of Standard Degrees of
(ppm) 95 % Limit 95 % Limit 95 % Limit
Deviation Freedom Deviation Freedom Deviation Freedom
0.06 0.0069 16 0.02 0.0052 8 0.01 0.018 7 0.05
0.60 0.040 14 0.11 0.028 7 0.08 0.134 6 0.37

&RS\ULJKWE\$670,QW O DOOULJKWVUHVHUYHG 7XH-XQ87& 10

'RZQORDGHGSULQWHGE\
OXLVULYDVJDUILDV ,QWHUWHN7HVWLQJ6HUYLFHV1$ SXUVXDQWWR/LFHQVH$JUHHPHQW1RIXUWKHUUHSURGXFWLRQVDXWKRUL]HG
 E223 − 25
for acceptance. Producers and customers need to have confi-
dence that results from different producers are comparable.
63. Keywords
63.1 acidity; analysis; arsenic; Baumé gravity; iron; non-
volatile matter; sulfur dioxide; sulfuric acid; total

SUMMARY OF CHANGES

Subcommittee D16.10 has identified the location of selected changes to this standard since the last issue
(E223 – 23ɛ1) that may impact the use of this standard. (Approved Feb.1, 2025.)

(1) Revised Eq 6 to correct non-volatile matter calculation.

ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentioned
in this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the risk
of infringement of such rights, are entirely their own responsibility.

This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years and
if not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standards
and should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of the
responsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you should
make your views known to the ASTM Committee on Standards, at the address shown below.

This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,
United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the above
address or at 610-832-9585 (phone), or through the ASTM website (www.astm.org/contact). Permission rights to photocopy the
standard may also be secured from the Copyright Clearance Center, 222 Rosewood Drive, Danvers, MA 01923, Tel: (978) 646-2600;
http://www.copyright.com/

&RS\ULJKWE\$670,QW O DOOULJKWVUHVHUYHG 7XH-XQ87& 11

'RZQORDGHGSULQWHGE\
OXLVULYDVJDUILDV ,QWHUWHN7HVWLQJ6HUYLFHV1$ SXUVXDQWWR/LFHQVH$JUHHPHQW1RIXUWKHUUHSURGXFWLRQVDXWKRUL]HG