ASTM D820-93

Standard Test Methods for Chemical Analysis of Soaps Containing Synthetic Detergents

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[deg]C (Oven Method) 5 and 6 Free Alkali or Free Acid 7 and 8 Anhydrous, Salt-Free, Soda Soap 9 and 12 Alcohol-Soluble Matter 13 and 14 Matter Insoluble in Water 15 Total Alkalinity of Matter Insoluble in Alcohol (Alkaline Salts) 16 and 17 Sodium Silicate 18 to 20 Phosphates 21 to 28 Phosphate (Colorimetric Method Using Molybdenum Blue) 29 to 34 Unsaponified and Unsaponifiable Matter 35 to 39 Free Fatty Matter 40 Chlorides in Alcohol-Soluble Matter 41 to 43 Rosin (McNicoll Method) 44 to 47 Synthetic Detergent (by Difference) 48 Neutral Inorganic Salts 49
1.3 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 and health practices and determine the applicability of regulatory limitations prior to use. >

General Information

• Status: Historical
• Publication Date: 31-Dec-1992
• Technical Committee: D12 - Soaps and Other Detergents
• Drafting Committee: D12.12 - Analysis and Specifications of Soaps, Synthetics, Detergents and their Components

Relations

• Replaced By: ASTM D820-93(2003) - Standard Test Methods for Chemical Analysis of Soaps Containing Synthetic Detergents
• Effective Date: 17-May-1993
• Referred By: ASTM D8179-18 - Standard Guide for Characterizing Detergents for the Cleaning of Clinically-used Medical Devices
• Effective Date: 01-Jan-1993
• Referred By: ASTM D459-16 - Standard Terminology Relating to Soaps and Other Detergents
• Effective Date: 01-Jan-1993

Standards Content (Sample)

NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
Designation: D 820 – 93
Standard Test Methods for
Chemical Analysis of Soaps Containing Synthetic
Detergents
This standard is issued under the fixed designation D 820; 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 (e) indicates an editorial change since the last revision or reapproval.
1. Scope D 2357 Qualitative Classification of Surfactants by Infrared
Absorption
1.1 These test methods cover procedures for the chemical
D 2358 Test Method for Separation of Active Ingredient
analysis of soaps containing synthetic detergents.
from Surfactant and Syndet Compositions
1.2 The analytical procedures appear in the following order:
D 3049 Test Method for Synthetic Anionic Ingredient by
Sections
Cationic Titration
Moisture and Other Matter Volatile at 105°C (Oven Method) 5 and 6
Free Alkali or Free Acid 7 and 8
3. Terminology
Anhydrous, Salt-Free, Soda Soap 9-12
3.1 Definitions:
Alcohol-Soluble Matter 13 and 14
Matter Insoluble in Water 15
3.2 The term synthetic detergent in these test methods is
Total Alkalinity of Matter Insoluble in Alcohol (Alkaline Salts) 16 and 17
defined in accordance with Terminology D 459, as follows:
Sodium Silicate 18-20
3.3 synthetic detergent—a detergent produced by chemical
Phosphates 21-28
Phosphate (Colorimetric Method Using Molybdenum Blue) 29-34
synthesis and comprising an organic composition other than
Unsaponified and Unsaponifiable Matter 35-39
soap.
Free Fatty Matter 40
3.4 For definitions of other terms used in these test methods,
Chlorides in Alcohol-Soluble Matter 41-43
Rosin (McNicoll Method) 44-47
refer to Terminology D 459.
Synthetic Detergent (by Difference) 48
Neutral, Inorganic Salts 49
4. Purity of Reagents and Materials
1.3 This standard does not purport to address all of the
4.1 Purity of Reagents—Reagent grade chemicals shall be
safety problems, if any, associated with its use. It is the
used in all tests. Unless otherwise indicated, it is intended that
responsibility of the user of this standard to establish appro-
all reagents shall conform to the specifications of the Commit-
priate safety and health practices and determine the applica-
tee on Analytical Reagents of the American Chemical Society,
bility of regulatory limitations prior to use.
where such specifications are available. Other grades may be
used, provided it is first ascertained that the reagent is of
2. Referenced Documents
sufficiently high purity to permit its use without lessening the
2.1 ASTM Standards:
accuracy of the determination.
D 216 Method for Distillation of Natural Gasoline
4.2 Unless otherwise indicated, references to water shall be
D 459 Terminology Relating to Soaps and Other Deter-
understood to mean reagent water conforming to Specification
gents
D 1193.
D 875 Method for Calculation of Olefins and Aromatics in
Petroleum Distillates from Bromine Number and Acid MOISTURE AND OTHER MATTER VOLATILE AT
Absorption 105°C (OVEN METHOD)
D 1193 Specification for Reagent Water
5. Apparatus
D 1768 Test Method for Sodium Alkylbenzene Sulfonate in
5.1 Dish—A porcelain or glass dish about 6 to 8 cm in
Synthetic Detergents by Ultraviolet Absorption
diameter and about 2 to 4 cm in depth will be required.
6. Procedure
These test methods are under the jurisdiction of ASTM Committee D-12 on
6.1 Weigh 5 6 0.01 g of the sample in the dish, and dry to
Soaps and Other Detergents and are the direct responsibility of Subcommittee
D12.12 on Analysis of Soaps and Synthetic Detergents.
Current edition approved May 17, 1993. Published July 1993. Originally
Reagent Chemicals, American Chemical Society Specifications, American
published as D 820 – 45. Last previous edition D 820 – 91.
Chemical Society, Washington, DC. For suggestions on the testing of reagents not
Discontinued, see 1987 Annual Book of ASTM Standards, Vol 05.01. listed by the American Chemical Society, see Analar Standards for Laboratory
Annual Book of ASTM Standards, Vol 15.04. Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia
Discontinued, see 1984 Annual Book of ASTM Standards, Vol 05.01. and National Formulary, U.S. Pharmaceutical Convention, Inc. (USPC), Rockville,
Annual Book of ASTM Standards, Vol 11.01. MD.
Copyright © ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, United States.
NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
D 820
constant weight in an air oven at a temperature of 105 6 2°C.
Constant weight is attained when heating for successive 1-h
periods shows a loss (or gain) of not more than 0.1 %.
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.
FREE ALKALI OR FREE ACID
7. Reagents
7.1 Ethyl Alcohol, Neutral (95 %)—Freshly boiled, reagent
grade, ethyl alcohol, 95 % or higher, neutral to phenolphtha-
lein, and containing only volatile denaturants, 95 mL, plus 5
mL of water.
7.2 Phenolphthalein Indicator Solution (10 g/litre)—
Dissolve1gof phenolphthalein in 50 mL of neutral ethyl
FIG. 1 Stokes Flask
alcohol (95 %) and mix with 50 mL of water (see 7.1).
8. Procedure
8.1 Weigh 5 to 10 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
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
surfactant mixtures containing borax are unreliable, due to solubility of
FIG. 2 Siphon
borax in hot alcohol.
ANHYDROUS, SALT-FREE, SODA SOAP
A
Distillation test:
Initial boiling point 35 to 38°C
9. Apparatus
Dry flask end point 52 to 60°C
Distilling under 54°C, min 95 %
9.1 Extraction Cylinder, 250-mL, graduated, glass-
Distilling under 40°C, max 60 %
stoppered, about 39 mm (1|n$ in.) in diameter and about 35.5
Specific gravity at 15.5/15.5°C (60/60°F) 0.630 to 0.660
cm (14 in.) in length. Color water-white
Doctor test sweet
9.2 Stokes Flask, 100-mL, round-bottom (with the bottom
Evaporation residue, 100 mL, max 0.0011 g
blown out), sealed onto a 150-mL Erlenmeyer flask. A diagram B
Copper-strip corrosion test noncorrosive
C
of the Stokes flask is shown in Fig. 1. Unsaturated compounds trace only permitted
Residue in distilling flask neutral to methyl orange
9.3 Siphon, consisting of a two-hole rubber stopper fitted
D
Blotter-strip odor test odorless within 12 min
E
with small-diameter glass tubing as shown in Fig. 2.
Aromatic compounds no nitrobenzene odor
Saponification value less than 1.0 mg KOH/100 mL
10. Reagents
______________
A 5
The distillation test shall be made in accordance with Method D 216. As a
10.1 Ethyl Alcohol, Neutral (95 %)—Freshly boiled, re-
check on the evaporation residue, 250 mL of the petroleum ether and 0.25 g of
agent grade, ethyl alcohol, 95 % or higher, neutral to phenol-
stearin or other hard fat (previously brought to constant weight by heating) when
phthalein, and containing only volatile denaturants, 95 mL,
dried as in the actual determination (10.4) shall not show an increase in weight
exceeding 0.003 g.
plus 5 mL of water.
B
The copper-strip corrosion test shall be made by inserting a small polished
10.2 Methyl Orange Indicator Solution (1 g/litre)—
copper strip into the petroleum ether in the distilling flask. There should be no
Dissolve 0.1 g of methyl orange in water and dilute to 100 mL.
appreciable darkening of the copper.
C
10.3 Petroleum Ether—The solvent used shall be of the
Unsaturated compounds shall be determined by the method for determining
olefins described in Method D 875.
pentane type, containing a minimum amount of isopentane,
D
Odor test: Immerse 1 in. of a strip of white unglazed blotting paper, approxi-
isohexane, and hexane, and boiling in the range 35 to 60°C.
mately 1 by 4 by 0.166 in. in size, in the petroleum ether for 30 s, remove the strip,
and allow to dry at room temperature in still air for 12 min.
E
Aromatic compounds: Add 5 drops of petroleum ether to 40 drops of sulfuric
Fischer Scientific A962, or its equivalent, is suitable for this purpose.
acid (H SO , sp gr 1.84) and 10 drops of nitric acid (HNO , sp gr 1.42) in a test
2 4 3
J. T. Baker Analyzed Reagent 9268, or its equivalent, is suitable for this
tube, warm for 10 min, allow to cool for 30 min, transfer to a shallow dish, and dilute
purpose. with water.
NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
D 820
10.4 Phenolphthalein Indicator Solution (10 g/litre)— 11.5 Dissolve the total fatty matter in 50 mL of neutral ethyl
Dissolve1gof phenolphthalein in 50 mL of neutral ethyl alcohol (95 % v) with warming. Add phenolphthalein indicator
alcohol (95 %) and then mix with 50 mL of water (see 10.1). and titrate with 0.1 NaOH solution to a pink end point.
10.5 Sodium Hydroxide, Standard Solution (0.1 N)
12. Calculations
—Prepare and standardize a 0.1 N sodium hydroxide (NaOH)
12.1 Calculate the percentage of anhydrous, salt-free, soda
solution.
10.6 Sodium Sulfate (Na SO ), anhydrous. soap as follows:
2 4
10.7 Sulfuric Acid, Standard (0.5 N)—Prepare and stan-
A 5 G 2 F (1)
dardize a 0.5 N sulfuric acid (H SO ) solution.
2 4
G 5 @~~VN 3 0.022! 1 E!/W# 3 100
10.8 Sulfuric Acid (sp gr 1.84)—Concentrated sulfuric acid
(H SO ).
2 4 where:
10.9 Sulfur Acid (1+1)—Gradually pour 10 g of concen- A 5 weight percent of anhydrous, salt-free, soda soap,
trated sulfuric acid (H SO ) (sp gr 1.84) onto 10 g of cracked G 5 weight percent of soda soap plus unsaponified and
2 4
ice made from distilled water, gently swirling the mixing unsaponifiable fatty matter,
F 5 weight percent of unsaponified and unsaponifiable
vessel; or gradually pour the acid down the sides of the mixing
fatty matter (Section 39),
vessel into an equal weight of water, swirling gently, while
V 5 millilitres of NaOH solution used in titration
submersing the vessel in an ice bath.
(11.5),
N 5 normality of NaOH solution,
11. Procedure
E 5 grams of extract (11.4), and
11.1 Weigh 2 6 0.001 g of the sample into a tared 250-mL
W 5 grams of sample (11.1), and
beaker. Add 25 mL of water and 25 mL of neutral ethyl alcohol
0.022 5 net gain in milliequivalent weight from the conver-
(95 %), and warm on the steam bath until solution is complete.
sion of the fatty acid to the sodium salt by
Cool, add 5 drops of methyl orange indicator solution, and
replacement of a proton with a sodium ion.
titrate with 0.5 N H SO to a pink color. Add 5 mL of H SO
2 4 2 4
(1+1) in excess.
ALCOHOL-SOLUBLE MATTER
11.2 Transfer the contents of the beaker to a 250-mL
13. Reagents
extraction cylinder or a Stokes flask, equipped with a siphon.
Wash the beaker alternately with equal parts of hot water and
13.1 Ethyl Alcohol, Neutral (95 %)—Freshly boiled, re-
hot ethyl alcohol (95 %), adding the washings to the extraction
agent grade, ethyl alcohol, 95 % or higher, neutral to phenol-
cylinder or Stokes flask. Keep the total volume for extraction phthalein, and containing only volatile denaturants, 95 mL
under 160 mL in the extraction cylinder, or within the
plus 5 mL of water.
constricted portion of the Stokes flask. Wash the beaker with a 13.2 Ethyl Alcohol, Neutral (absolute)—Freshly boiled ab-
small amount of petroleum ether to remove any traces of fatty
solute ethyl alcohol, neutral to phenolphthalein.
acids and fatty matter and add to the extraction cylinder or
14. Procedure
Stokes flask. Cool the cylinder or flask under tap water to a
temperature not to exceed 25°C. Add 50 mL of petroleum ether 14.1 Weigh 2 6 0.001 g of the sample into a 250-mL
and allow to stand for |n$ h without shaking. Remove the beaker. Add 100 mL of neutral ethyl alcohol (95 %), cover the
greater part of the fatty acids by drawing off the petroleum beaker, and heat on the steam bath with frequent stirring and
ether layer as closely as possible, by means of a glass siphon, maceration of the sample until completely disintegrated. Let
into a 500-mL separatory funnel. Repeat the extractions five
settle and filter the supernatant liquid through a tared Gooch
more times with petroleum ether, using 50-mL portions, and crucible with a glass wool pad, with suction into a tared
shaking the cylinder thoroughly each time.
300-mL Erlenmeyer flask, retaining as much of the residue as
possible in the beaker. Repeat this extraction three times with
NOTE 3—If an emulsion appears at this point, it may be broken by the
25-mL portions of hot neutral ethyl alcohol (95 %), each time
addition of 10 g of anhydrous Na SO .
2 4
retaining as much of the residue as possible in the beaker.
11.3 Combine the petroleum ether extracts and wash with
Finally, evaporate any remaining alcohol and dissolve the
small portions of distilled water until the water washings are no
residue in the smallest possible quantity of hot water (5 mL if
longer acid to methyl orange indicator solution. Dry the
sufficient). Reprecipitate the alcohol-insoluble matter by
combined, washed, petroleum ether extracts with anhydrous
slowly adding, while stirring vigorously, 50 mL of neutral ethyl
Na SO , and filter through paper into the original tared 250-mL
2 4
alcohol (absolute).
beaker. Wash the separatory funnel with two small portions of
NOTE 4—Solution and reprecipitation of alcohol-insoluble matter is
petroleum ether, filtering and adding the washings to the
necessary for complete separation from alcohol-soluble matter.
beaker.
11.4 Evaporate the petroleum ether extract on the steam 14.2 Heat the solution to boiling on the steam bath, filter,
bath until about 1 mL remains. Then swirl manually until the and transfer the precipitate quantitatively to the Gooch cru-
last trace of solvent evaporates and the odor of petroleum ether cible, washing several times with neutral ethyl alcohol (95 %).
is no longer perceptible. Cool in a desiccator and weigh as total Evaporate the com
...