1、Designation: D 820 93 (Reapproved 2003)Standard Test Methods forChemical Analysis of Soaps Containing SyntheticDetergents1This standard is issued under the fixed designation D 820; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, th
2、e year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 These test methods cover procedures for the chemicalanalysis of soaps containing synthetic detergents.1.2 T
3、he analytical procedures appear in the following order:SectionsMoisture and Other Matter Volatile at 105C (Oven Method) 5 and 6Free Alkali or Free Acid 7 and 8Anhydrous, Salt-Free, Soda Soap 9-12Alcohol-Soluble Matter 13 and 14Matter Insoluble in Water 15Total Alkalinity of Matter Insoluble in Alcoh
4、ol (Alkaline Salts) 16 and 17Sodium Silicate 18-20Phosphates 21-28Phosphate (Colorimetric Method Using Molybdenum Blue) 29-34Unsaponified and Unsaponifiable Matter 35-39Free Fatty Matter 40Chlorides in Alcohol-Soluble Matter 41-43Rosin (McNicoll Method) 44-47Synthetic Detergent (by Difference) 48Neu
5、tral, Inorganic Salts 491.3 This standard does not purport to address all of thesafety problems, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prio
6、r to use.2. Referenced Documents2.1 ASTM Standards:D 216 Method for Distillation of Natural Gasoline2D 459 Terminology Relating to Soaps and Other Deter-gents3D 875 Method for Calculation of Olefins and Aromatics inPetroleum Distillates from Bromine Number and AcidAbsorption4D 1193 Specification for
7、 Reagent Water5D 1768 Test Method for Sodium Alkylbenzene Sulfonate inSynthetic Detergents by Ultraviolet Absorption3D 2357 Qualitative Classification of Surfactants by InfraredAbsorption3D 2358 Test Method for Separation of Active Ingredientfrom Surfactant and Syndet Compositions3D 3049 Test Method
8、 for Synthetic Anionic Ingredient byCationic Titration33. Terminology3.1 Definitions:3.2 The term synthetic detergent in these test methods isdefined in accordance with Terminology D 459, as follows:3.3 synthetic detergenta detergent produced by chemicalsynthesis and comprising an organic compositio
9、n other thansoap.3.4 For definitions of other terms used in these test methods,refer to Terminology D 459.4. Purity of Reagents and Materials4.1 Purity of ReagentsReagent grade chemicals shall beused in all tests. Unless otherwise indicated, it is intended thatall reagents shall conform to the speci
10、fications of the Commit-tee on Analytical Reagents of the American Chemical Society,where such specifications are available.6Other grades may beused, provided it is first ascertained that the reagent is ofsufficiently high purity to permit its use without lessening theaccuracy of the determination.4
11、.2 Unless otherwise indicated, references to water shall beunderstood to mean reagent water conforming to SpecificationD 1193.MOISTURE AND OTHER MATTER VOLATILE AT105C (OVEN METHOD)5. Apparatus5.1 DishA porcelain or glass dish about 6 to 8 cm indiameter and about 2 to 4 cm in depth will be required.
12、1These test methods are under the jurisdiction of ASTM Committee D12 onSoaps and Other Detergents and are the direct responsibility of SubcommitteeD12.12 on Analysis of Soaps and Synthetic Detergents.Current edition approved May 17, 1993. Published July 1993. Originallypublished as D 820 45. Last pr
13、evious edition D 820 91.2Discontinued, see 1987 Annual Book of ASTM Standards, Vol 05.01.3Annual Book of ASTM Standards, Vol 15.04.4Discontinued, see 1984 Annual Book of ASTM Standards, Vol 05.01.5Annual Book of ASTM Standards, Vol 11.01.6Reagent Chemicals, American Chemical Society Specifications,
14、AmericanChemical Society, Washington, DC. For suggestions on the testing of reagents notlisted by the American Chemical Society, see Analar Standards for LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmaceutical Convention, Inc.
15、 (USPC), Rockville,MD.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.6. Procedure6.1 Weigh 5 6 0.01 g of the sample in the dish, and dry toconstant weight in an air oven at a temperature of 105 6 2C.Constant weight is attained when
16、heating for successive 1-hperiods shows a loss (or gain) of not more than 0.1 %.NOTE 1Because of its established use in the trade, the term weight isemployed in these methods in place of the technically correct term mass.FREE ALKALI OR FREE ACID7. Reagents7.1 Ethyl Alcohol, Neutral (95 %)Freshly boi
17、led, reagentgrade, ethyl alcohol, 95 % or higher, neutral to phenolphtha-lein, and containing only volatile denaturants, 95 mL,7plus 5mL of water.7.2 Phenolphthalein Indicator Solution (10 g/litre)Dissolve1gofphenolphthalein in 50 mL of neutral ethylalcohol (95 %) and mix with 50 mL of water (see 7.
18、1).8. Procedure8.1 Weigh 5 to 10 6 0.01 g of the sample into a 300-mLErlenmeyer flask. Add 200 mL of neutral ethyl alcohol (95 %).Equip the flask with an air-cooled reflux condenser, and digestthe sample on a steam bath until the soap is dissolved (see Note2). Remove the condenser, add 0.5 mL of the
19、 phenolphthaleinindicator solution, and titrate immediately with standard acidor alkali. Calculate as NaOH, if alkaline, or as oleic acid, ifacid.NOTE 2In the analysis of soaps known to contain little or no alkalinesalts, it is unnecessary to filter the hot alcoholic soap solution. However,the filtr
20、ation should be carried out in all cases where alkaline salts such assilicates, phosphates, borates, and similar salts are present, since these areknown to affect the free alkali determination. Free alkali figures in soap orsurfactant mixtures containing borax are unreliable, due to solubility ofbor
21、ax in hot alcohol.ANHYDROUS, SALT-FREE, SODA SOAP9. Apparatus9.1 Extraction Cylinder, 250-mL, graduated, glass-stoppered, about 39 mm (112 in.) in diameter and about 35.5cm (14 in.) in length.9.2 Stokes Flask, 100-mL, round-bottom (with the bottomblown out), sealed onto a 150-mL Erlenmeyer flask. A
22、diagramof the Stokes flask is shown in Fig. 1.9.3 Siphon, consisting of a two-hole rubber stopper fittedwith small-diameter glass tubing as shown in Fig. 2.10. Reagents10.1 Ethyl Alcohol, Neutral (95 %)Freshly boiled, re-agent grade, ethyl alcohol, 95 % or higher, neutral to phenol-phthalein, and co
23、ntaining only volatile denaturants, 95 mL,7plus 5 mL of water.10.2 Methyl Orange Indicator Solution (1 g/litre)Dissolve 0.1 g of methyl orange in water and dilute to 100 mL.10.3 Petroleum EtherThe solvent used shall be of thepentane type, containing a minimum amount of isopentane,isohexane, and hexa
24、ne, and boiling in the range 35 to 60C.8Distillation test:AInitial boiling point 35 to 38CDry flask end point 52 to 60CDistilling under 54C, min 95 %Distilling under 40C, max 60 %Specific gravity at 15.5/15.5C (60/60F) 0.630 to 0.660Color water-whiteDoctor test sweetEvaporation residue, 100 mL, max
25、0.0011 gCopper-strip corrosion testBnoncorrosiveUnsaturated compoundsCtrace only permittedResidue in distilling flask neutral to methyl orangeBlotter-strip odor testDodorless within 12 minAromatic compoundsEno nitrobenzene odorSaponification value less than 1.0 mg KOH/100 mL_AThe distillation test s
26、hall be made in accordance with Method D 216. As acheck on the evaporation residue, 250 mL of the petroleum ether and 0.25 g ofstearin or other hard fat (previously brought to constant weight by heating) whendried as in the actual determination (10.4) shall not show an increase in weightexceeding 0.
27、003 g.BThe copper-strip corrosion test shall be made by inserting a small polishedcopper strip into the petroleum ether in the distilling flask. There should be noappreciable darkening of the copper.7Fischer Scientific A962, or its equivalent, is suitable for this purpose.8J. T. Baker Analyzed Reage
28、nt 9268, or its equivalent, is suitable for thispurpose.FIG. 1 Stokes FlaskFIG. 2 SiphonD 820 93 (2003)2CUnsaturated compounds shall be determined by the method for determiningolefins described in Method D 875.DOdor test: Immerse 1 in. of a strip of white unglazed blotting paper, approxi-mately 1 by
29、 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.EAromatic compounds: Add 5 drops of petroleum ether to 40 drops of sulfuricacid (H2SO4, sp gr 1.84) and 10 drops of nitric acid (HNO3, sp gr 1.42) in a testtube, wa
30、rm for 10 min, allow to cool for 30 min, transfer to a shallow dish, and dilutewith water.10.4 Phenolphthalein Indicator Solution (10 g/litre)Dissolve1gofphenolphthalein in 50 mL of neutral ethylalcohol (95 %) and then mix with 50 mL of water (see 10.1).10.5 Sodium Hydroxide, Standard Solution (0.1
31、N)Prepare and standardize a 0.1 N sodium hydroxide (NaOH)solution.10.6 Sodium Sulfate (Na2SO4), anhydrous.10.7 Sulfuric Acid, Standard (0.5 N)Prepare and stan-dardize a 0.5 N sulfuric acid (H2SO4) solution.10.8 Sulfuric Acid (sp gr 1.84)Concentrated sulfuric acid(H2SO4).10.9 Sulfur Acid (1+1)Gradual
32、ly pour 10 g of concen-trated sulfuric acid (H2SO4) (sp gr 1.84) onto 10 g of crackedice made from distilled water, gently swirling the mixingvessel; or gradually pour the acid down the sides of the mixingvessel into an equal weight of water, swirling gently, whilesubmersing the vessel in an ice bat
33、h.11. Procedure11.1 Weigh 2 6 0.001 g of the sample into a tared 250-mLbeaker. Add 25 mL of water and 25 mL of neutral ethyl alcohol(95 %), and warm on the steam bath until solution is complete.Cool, add 5 drops of methyl orange indicator solution, andtitrate with 0.5 N H2SO4to a pink color. Add 5 m
34、L of H2SO4(1+1) in excess.11.2 Transfer the contents of the beaker to a 250-mLextraction cylinder or a Stokes flask, equipped with a siphon.Wash the beaker alternately with equal parts of hot water andhot ethyl alcohol (95 %), adding the washings to the extractioncylinder or Stokes flask. Keep the t
35、otal volume for extractionunder 160 mL in the extraction cylinder, or within theconstricted portion of the Stokes flask. Wash the beaker with asmall amount of petroleum ether to remove any traces of fattyacids and fatty matter and add to the extraction cylinder orStokes flask. Cool the cylinder or f
36、lask under tap water to atemperature not to exceed 25C. Add 50 mL of petroleum etherand allow to stand for12 h without shaking. Remove thegreater part of the fatty acids by drawing off the petroleumether layer as closely as possible, by means of a glass siphon,into a 500-mL separatory funnel. Repeat
37、 the extractions fivemore times with petroleum ether, using 50-mL portions, andshaking the cylinder thoroughly each time.NOTE 3If an emulsion appears at this point, it may be broken by theaddition of 10 g of anhydrous Na2SO4.11.3 Combine the petroleum ether extracts and wash withsmall portions of di
38、stilled water until the water washings are nolonger acid to methyl orange indicator solution. Dry thecombined, washed, petroleum ether extracts with anhydrousNa2SO4, and filter through paper into the original tared 250-mLbeaker. Wash the separatory funnel with two small portions ofpetroleum ether, f
39、iltering and adding the washings to thebeaker.11.4 Evaporate the petroleum ether extract on the steambath until about 1 mL remains. Then swirl manually until thelast trace of solvent evaporates and the odor of petroleum etheris no longer perceptible. Cool in a desiccator and weigh as totalfatty matt
40、er, which is defined as fatty and rosin acids plusunsaponified and unsaponifiable fatty matter.11.5 Dissolve the total fatty matter in 50 mL of neutral ethylalcohol (95 % v) with warming. Add phenolphthalein indicatorand titrate with 0.1 NaOH solution to a pink end point.12. Calculations12.1 Calcula
41、te the percentage of anhydrous, salt-free, sodasoap as follows:A 5 G 2 F (1)G 5 VN 3 0.022! 1 E!/W# 3 100where:A = weight percent of anhydrous, salt-free, soda soap,G = weight percent of soda soap plus unsaponified andunsaponifiable fatty matter,F = weight percent of unsaponified and unsaponifiablef
42、atty matter (Section 39),V = millilitres of NaOH solution used in titration(11.5),N = normality of NaOH solution,E = grams of extract (11.4), andW = grams of sample (11.1), and0.022 = net gain in milliequivalent weight from the conver-sion of the fatty acid to the sodium salt byreplacement of a prot
43、on with a sodium ion.ALCOHOL-SOLUBLE MATTER13. Reagents13.1 Ethyl Alcohol, Neutral (95 %)Freshly boiled, re-agent grade, ethyl alcohol, 95 % or higher, neutral to phenol-phthalein, and containing only volatile denaturants, 95 mL7plus 5 mL of water.13.2 Ethyl Alcohol, Neutral (absolute)Freshly boiled
44、 ab-solute ethyl alcohol, neutral to phenolphthalein.714. Procedure14.1 Weigh 2 6 0.001 g of the sample into a 250-mLbeaker. Add 100 mL of neutral ethyl alcohol (95 %), cover thebeaker, and heat on the steam bath with frequent stirring andmaceration of the sample until completely disintegrated. Lets
45、ettle and filter the supernatant liquid through a tared Goochcrucible with a glass wool pad, with suction into a tared300-mL Erlenmeyer flask, retaining as much of the residue aspossible in the beaker. Repeat this extraction three times with25-mL portions of hot neutral ethyl alcohol (95 %), each ti
46、meretaining as much of the residue as possible in the beaker.Finally, evaporate any remaining alcohol and dissolve theresidue in the smallest possible quantity of hot water (5 mL ifsufficient). Reprecipitate the alcohol-insoluble matter byslowly adding, while stirring vigorously, 50 mL of neutral et
47、hylalcohol (absolute).NOTE 4Solution and reprecipitation of alcohol-insoluble matter isnecessary for complete separation from alcohol-soluble matter.D 820 93 (2003)314.2 Heat the solution to boiling on the steam bath, filter,and transfer the precipitate quantitatively to the Gooch cru-cible, washing
48、 several times with neutral ethyl alcohol (95 %).Evaporate the combined filtrate and washings in the Erlenm-eyer flask on the steam bath, and then dry to constant weight at105 6 2C. Calculate total alcohol-soluble matter.14.3 Reserve the flask and contents for the determination offree fatty matter (
49、Section 37). Reserve the Gooch crucible andcontents, without drying, for the determination of matterinsoluble in water (Section 15) and total alkalinity of matterinsoluble in alcohol (alkaline salts) (Section 17).MATTER INSOLUBLE IN WATER15. Procedure15.1 Wash the alcohol-insoluble matter retained in theGooch crucible (Section 14) thoroughly with hot water untilthe washings are no longer alkaline to phenolphthalein. Re-serve the filtrate for determination of total alkalinity of matterinsoluble in alcohol (Section 17). Dry the crucibl
