ASTM D820-93(2023)
(Test Method)Standard Test Methods for Chemical Analysis of Soaps Containing Synthetic Detergents
Standard Test Methods for Chemical Analysis of Soaps Containing Synthetic Detergents
ABSTRACT
These test methods detail the standard procedures for the chemical analysis of soaps containing synthetic detergents. The analytical procedures include the determination of the following chemical properties and substances: moisture and other matter volatile at a specified temperature; free alkali or free acid; anhydrous, salt-free soda soap; alcohol-soluble matter; matter insoluble in water; total alkalinity of matter insoluble in alcohol (alkaline salts); sodium silicate; phosphates; phosphates by colorimetric method using molybdenum blue); unsaponified and unsaponifiable matter; free fatty matter; chlorides in alcohol-soluble matter; rosin by McNicoll method; synthetic detergent by difference; and neutral inorganic salts.
SCOPE
1.1 These test methods cover procedures for the chemical analysis of soaps containing synthetic detergents.
1.2 The analytical procedures appear in the following order:
Sections
Moisture and Other Matter Volatile at 105°C (Oven Method)
5 and 6
Free Alkali or Free Acid
7 and 8
Anhydrous, Salt-Free, Soda Soap
9 – 12
Alcohol-Soluble Matter
13 and 14
Matter Insoluble in Water
15 and 15
Total Alkalinity of Matter Insoluble in Alcohol (Alkaline Salts)
16 and 17
Sodium Silicate
18 – 20
Phosphates
21 – 28
Phosphate (Colorimetric Method Using Molybdenum Blue)
29 – 34
Unsaponified and Unsaponifiable Matter
35 – 39
Free Fatty Matter
40
Chlorides in Alcohol-Soluble Matter
41 – 43
Rosin (McNicoll Method)
44 – 47
Synthetic Detergent (by Difference)
48
Neutral, Inorganic Salts
49
1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.4 This standard does not purport to address all of the safety problems, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
1.5 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.
General Information
Relations
Standards Content (Sample)
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: D820 − 93 (Reapproved 2023)
Standard Test Methods for
Chemical Analysis of Soaps Containing Synthetic
Detergents
This standard is issued under the fixed designation D820; 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.
1. Scope 2. Referenced Documents
1.1 These test methods cover procedures for the chemical 2.1 ASTM Standards:
analysis of soaps containing synthetic detergents. D216 Method of Test for Distillation of Natural Gasoline
(Withdrawn 1988)
1.2 The analytical procedures appear in the following order:
D459 Terminology Relating to Soaps and Other Detergents
Sections
D875 Method for Calculating of Olefins and Aromatics in
Moisture and Other Matter Volatile at 105°C (Oven Method) 5 and 6 Petroleum Distillates from Bromine Number and Acid
Free Alkali or Free Acid 7 and 8
Absorption (Withdrawn 1984)
Anhydrous, Salt-Free, Soda Soap 9 – 12
D1193 Specification for Reagent Water
Alcohol-Soluble Matter 13 and 14
Matter Insoluble in Water 15 and 15 D1768 Test Method for Sodium Alkylbenzene Sulfonate in
Total Alkalinity of Matter Insoluble in Alcohol (Alkaline Salts) 16 and 17
Synthetic Detergents by Ultraviolet Absorption
Sodium Silicate 18 – 20
D2357 for Qualitative Classification of Surfactants by Infra-
Phosphates 21 – 28
Phosphate (Colorimetric Method Using Molybdenum Blue) 29 – 34
red Absorption
Unsaponified and Unsaponifiable Matter 35 – 39
D2358 Test Method for Separation of Active Ingredient from
Free Fatty Matter 40
Surfactant and Syndet Compositions
Chlorides in Alcohol-Soluble Matter 41 – 43
Rosin (McNicoll Method) 44 – 47 D3049 Test Method for Synthetic Anionic Ingredient by
Synthetic Detergent (by Difference) 48
Cationic Titration
Neutral, Inorganic Salts 49
1.3 The values stated in SI units are to be regarded as
3. Terminology
standard. No other units of measurement are included in this
3.1 Definitions:
standard.
3.2 The term synthetic detergent in these test methods is
1.4 This standard does not purport to address all of the
defined in accordance with Terminology D459, as follows:
safety problems, if any, associated with its use. It is the
3.3 synthetic detergent—a detergent produced by chemical
responsibility of the user of this standard to establish appro-
synthesis and comprising an organic composition other than
priate safety, health, and environmental practices and deter-
soap.
mine the applicability of regulatory limitations prior to use.
1.5 This international standard was developed in accor-
3.4 For definitions of other terms used in these test methods,
dance with internationally recognized principles on standard-
refer to Terminology D459.
ization established in the Decision on Principles for the
Development of International Standards, Guides and Recom- 4. Purity of Reagents and Materials
mendations issued by the World Trade Organization Technical
4.1 Purity of Reagents—Reagent grade chemicals shall be
Barriers to Trade (TBT) Committee.
used in all tests. Unless otherwise indicated, it is intended that
These test methods are under the jurisdiction of ASTM Committee D12 on
Soaps and Other Detergentsand are the direct responsibility of Subcommittee For referenced ASTM standards, visit the ASTM website, www.astm.org, or
D12.12 on Analysis and Specifications of Soaps, Synthetics, Detergents and their contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Components. Standards volume information, refer to the standard’s Document Summary page on
Current edition approved July 1, 2023. Published July 2023. Originally approved the ASTM website.
in 1945. Last previous edition approved in 2016 as D820 – 93 (2016). DOI: The last approved version of this historical standard is referenced on
10.1520/D0820-93R23. www.astm.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D820 − 93 (2023)
surfactant mixtures containing borax are unreliable, due to solubility of
all reagents shall conform to the specifications of the Commit-
borax in hot alcohol.
tee on Analytical Reagents of the American Chemical Society,
where such specifications are available. Other grades may be
ANHYDROUS, SALT-FREE, SODA SOAP
used, provided it is first ascertained that the reagent is of
sufficiently high purity to permit its use without lessening the
9. Apparatus
accuracy of the determination.
9.1 Extraction Cylinder, 250 mL, graduated, glass-
4.2 Unless otherwise indicated, references to water shall be
stoppered, about 39 mm (1 ⁄2 in.) in diameter and about
understood to mean reagent water conforming to Specification 35.5 cm (14 in.) in length.
D1193.
9.2 Stokes Flask, 100 mL, round-bottom (with the bottom
blown out), sealed onto a 150 mL Erlenmeyer flask. A diagram
MOISTURE AND OTHER MATTER VOLATILE AT
of the Stokes flask is shown in Fig. 1.
105 °C (OVEN METHOD)
9.3 Siphon, consisting of a two-hole rubber stopper fitted
5. Apparatus
with small-diameter glass tubing as shown in Fig. 2.
5.1 Dish—A porcelain or glass dish about 6 cm to 8 cm in
10. Reagents
diameter and about 2 cm to 4 cm in depth will be required.
10.1 Ethyl Alcohol, Neutral (95 %) —Freshly boiled, re-
6. Procedure agent grade, ethyl alcohol, 95 % or higher, neutral to
phenolphthalein, and containing only volatile denaturants,
6.1 Weigh 5 g 6 0.01 g of the sample in the dish, and dry to
95 mL, plus 5 mL of water.
constant weight in an air oven at a temperature of 105 °C 6
10.2 Methyl Orange Indicator Solution (1 g/litre)—Dissolve
2 °C. Constant weight is attained when heating for successive
0.1 g of methyl orange in water and dilute to 100 mL.
1 h periods shows a loss (or gain) of not more than 0.1 %.
10.3 Petroleum Ether—The solvent used shall be of the
NOTE 1—Because of its established use in the trade, the term weight is
employed in these methods in place of the technically correct term mass. pentane type, containing a minimum amount of isopentane,
isohexane, and hexane, and boiling in the range 35 °C to
FREE ALKALI OR FREE ACID
60 °C.
A
Distillation test:
7. Reagents
Initial boiling point 35 °C to 38 °C
Dry flask end point 52 °C to 60 °C
7.1 Ethyl Alcohol, Neutral (95 %) —Freshly boiled, reagent
Distilling under 54 °C, min 95 %
grade, ethyl alcohol, 95 % or higher, neutral to
Distilling under 40 °C, max 60 %
phenolphthalein, and containing only volatile denaturants,
Specific gravity at 15.5/15.5 °C (60 ⁄60 °F) 0.630 to 0.660
Color water-white
95 mL, plus 5 mL of water.
Doctor test sweet
Evaporation residue, 100 mL, max 0.0011 g
7.2 Phenolphthalein Indicator Solution (10 g/litre)—
B
Copper-strip corrosion test noncorrosive
Dissolve 1 g of phenolphthalein in 50 mL of neutral ethyl
C
Unsaturated compounds trace only permitted
alcohol (95 %) and mix with 50 mL of water (see 7.1).
Residue in distilling flask neutral to methyl orange
D
Blotter-strip odor test odorless within 12 min
E
Aromatic compounds no nitrobenzene odor
8. Procedure
Saponification value less than 1.0 mg KOH/100 mL
8.1 Weigh 5 g to 10 g 6 0.01 g of the sample into a 300 mL
Erlenmeyer flask. Add 200 mL of neutral ethyl alcohol (95 %).
Equip the flask with an air-cooled reflux condenser, and digest
J. T. Baker Analyzed Reagent 9268, or its equivalent, is suitable for this
purpose.
the sample on a steam bath until the soap is dissolved (see Note
2). Remove the condenser, add 0.5 mL of the phenolphthalein
indicator solution, and titrate immediately with standard acid
or alkali. Calculate as NaOH, if alkaline, or as oleic acid, if
acid.
NOTE 2—In the analysis of soaps known to contain little or no alkaline
salts, it is unnecessary to filter the hot alcoholic soap solution. However,
the filtration should be carried out in all cases where alkaline salts such as
silicates, phosphates, borates, and similar salts are present, since these are
known to affect the free alkali determination. Free alkali figures in soap or
ACS Reagent Chemicals, Specifications and Procedures for Reagents and
Standard-Grade Reference Materials, American Chemical Society, Washington,
DC. For suggestions on the testing of reagents not listed by the American Chemical
Society, see Analar Standards for Laboratory Chemicals, BDH Ltd., Poole, Dorset,
U.K., and the United States Pharmacopeia and National Formulary, U.S. Pharma-
copeial Convention, Inc. (USPC), Rockville, MD.
Fischer Scientific A962, or its equivalent, is suitable for this purpose. FIG. 1 Stokes Flask
D820 − 93 (2023)
Wash the beaker alternately with equal parts of hot water and
hot ethyl alcohol (95 %), adding the washings to the extraction
cylinder or Stokes flask. Keep the total volume for extraction
under 160 mL in the extraction cylinder, or within the
constricted portion of the Stokes flask. Wash the beaker with a
small amount of petroleum ether to remove any traces of fatty
acids and fatty matter and add to the extraction cylinder or
Stokes flask. Cool the cylinder or flask under tap water to a
temperature not to exceed 25 °C. Add 50 mL of petroleum
ether and allow to stand for ⁄2 h without shaking. Remove the
greater part of the fatty acids by drawing off the petroleum
ether layer as closely as possible, by means of a glass siphon,
into a 500 mL separatory funnel. Repeat the extractions five
more times with petroleum ether, using 50 mL portions, and
FIG. 2 Siphon
shaking the cylinder thoroughly each time.
NOTE 3—If an emulsion appears at this point, it may be broken by the
A
The distillation test shall be made in accordance with Method D216. As a check
addition of 10 g of anhydrous Na SO .
2 4
on the evaporation residue, 250 mL of the petroleum ether and 0.25 g of stearin or
other hard fat (previously brought to constant weight by heating) when dried as in
11.3 Combine the petroleum ether extracts and wash with
the actual determination (10.4) shall not show an increase in weight exceeding
0.003 g.
small portions of distilled water until the water washings are no
B
The copper-strip corrosion test shall be made by inserting a small polished
longer acid to methyl orange indicator solution. Dry the
copper strip into the petroleum ether in the distilling flask. There should be no
appreciable darkening of the copper. combined, washed, petroleum ether extracts with anhydrous
C
Unsaturated compounds shall be determined by the method for determining
Na SO , and filter through paper into the original tared 250 mL
2 4
olefins described in Method D875.
D
beaker. Wash the separatory funnel with two small portions of
Odor test: Immerse 1 in. of a strip of white unglazed blotting paper, approxi-
mately 1 in. by 4 in. by 0.166 in. in size, in the petroleum ether for 30 s, remove the
petroleum ether, filtering and adding the washings to the
strip, and allow to dry at room temperature in still air for 12 min.
beaker.
E
Aromatic compounds: Add 5 drops of petroleum ether to 40 drops of sulfuric acid
(H SO , sp gr 1.84) and 10 drops of nitric acid (HNO , sp gr 1.42) in a test tube,
2 4 3
11.4 Evaporate the petroleum ether extract on the steam
warm for 10 min, allow to cool for 30 min, transfer to a shallow dish, and dilute with
water.
bath until about 1 mL remains. Then swirl manually until the
last trace of solvent evaporates and the odor of petroleum ether
10.4 Phenolphthalein Indicator Solution (10 g/litre)—
is no longer perceptible. Cool in a desiccator and weigh as total
Dissolve 1 g of phenolphthalein in 50 mL of neutral ethyl
alcohol (95 %) and then mix with 50 mL of water (see 10.1). fatty matter, which is defined as fatty and rosin acids plus
unsaponified and unsaponifiable fatty matter.
10.5 Sodium Hydroxide, Standard Solution (0.1 N)—
Prepare and standardize a 0.1 N sodium hydroxide (NaOH)
11.5 Dissolve the total fatty matter in 50 mL of neutral ethyl
solution.
alcohol (95 % v) with warming. Add phenolphthalein indicator
and titrate with 0.1 NaOH solution to a pink end point.
10.6 Sodium Sulfate (Na SO ), anhydrous.
2 4
10.7 Sulfuric Acid, Standard (0.5 N)—Prepare and standard-
12. Calculations
ize a 0.5 N sulfuric acid (H SO ) solution.
2 4
12.1 Calculate the percentage of anhydrous, salt-free, soda
10.8 Sulfuric Acid (sp gr 1.84)—Concentrated sulfuric acid
soap as follows:
(H SO ).
2 4
10.9 Sulfur Acid (1+1)—Gradually pour 10 g of concen- A 5 G 2 F (1)
trated sulfuric acid (H SO ) (sp gr 1.84) onto 10 g of cracked
2 4
G 5 VN × 0.022 1E /W × 100
@~~ ! ! #
ice made from distilled water, gently swirling the mixing
vessel; or gradually pour the acid down the sides of the mixing
where:
vessel into an equal weight of water, swirling gently, while
A = weight percent of anhydrous, salt-free, soda soap,
submersing the vessel in an ice bath.
G = weight percent of soda soap plus unsaponified and
unsaponifiable fatty matter,
11. Procedure
F = weight percent of unsaponified and unsaponifiable
11.1 Weigh 2 g 6 0.001 g of the sample into a tared 250 mL
fatty matter (Section 39),
beaker. Add 25 mL of water and 25 mL of neutral ethyl alcohol
V = millilitres of NaOH solution used in titration (11.5),
(95 %), and warm on the steam bath until solution is complete.
N = normality of NaOH solution,
Cool, add 5 drops of methyl orange indicator solution, and
E = grams of extract (11.4), and
W = grams of sample (11.1), and
titrate with 0.5 N H SO to a pink color. Add 5 mL of H SO
2 4 2 4
0.022 = net gain in milliequivalent weight from the conver-
(1+1) in excess.
sion of the fatty acid to the sodium salt by replace-
11.2 Transfer the contents of the beaker to a 250 mL
ment of a proton with a sodium ion.
extraction cylinder or a Stokes flask, equipped with a siphon.
D820 − 93 (2023)
ALCOHOL-SOLUBLE MATTER 16.2 Methyl Orange Indicator Solution (1 g/litre)—Dissolve
0.1 g of methyl orange in water and dilute to 100 mL.
13. Reagents
13.1 Ethyl Alcohol, Neutral (95 %) —Freshly boiled, re- 17. Procedure
agent grade, ethyl alcohol, 95 % or higher, neutral to
17.1 Titrate the water solution obtained in the determination
phenolphthalein, and containing only volatile denaturants,
of matter insoluble in water (Section 15) with the standard 1 N
95 mL plus 5 mL of water.
hydrochloric acid solution of 16.1, using methyl orange as
13.2 Ethyl Alcohol, Neutral (absolute) —Freshly boiled indicator.
absolute ethyl alcohol, neutral to phenolphthalein.
17.2 Calculate the alkalinity as sodium
...
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