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 2016)
Standard Test Methods for
Chemical Analysis of Soaps Containing Synthetic Detergents 1 This standard is issued under the fixed designation D820; the number immediately following the designation indicates the year of original origin al adoption or, in the case of revis revision, ion, the year of last revision. revision. A number in paren parenthese thesess indicates the year of last reappr reapproval. oval. A superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Sco Scope pe 1.1 These test methods cover procedures procedures for the chemica chemicall analysis of soaps containing synthetic detergents. 1.2 The analytical analytical procedures procedures appear in the follow following ing order: Sections Moisture and Other Matter Volatile at 105°C (Oven Method) 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 Phosphate (Colorimetric Method Using Molybdenum Blue) Unsaponified and Unsaponifiable Matter Free Fatty Matter Chlorides in Alcohol-Soluble Matter Rosin (McNicoll Method) Synthetic Detergent (by Difference) Neutral, Inorganic Salts
5 and 6 7 and 8 9 – 12 13 and 14 15 and 15 16 and 17 18 – 20 21 – 28 29 – 34 35 – 39 40 41 – 43 44 – 47 48 49
1.3 Th 1.3 Thee va valu lues es sta stated ted in SI un units its are to be re rega gard rded ed as standard. No other units of measurement are included in this standard. standard d doe doess not purport purport to add addre ress ss all of the 1.4 This standar safet sa fetyy pr prob oble lems ms,, if an anyy, as asso soci ciat ated ed wi with th its us use. e. It is th thee responsibility of the user of this standard to establish appro priate safety and health practices and determine the applicability of regulatory limitations prior to use.
2. Referenc Referenced ed Documents Documents 2.1 ASTM Standards:2
1 These test methods are under the jurisdiction of ASTM Committee D12 on Soaps and Other Detergentsan Detergentsand d are the direct responsibilit responsibility y of Subco Subcommitte mmitteee D12.12 on D12.12 on Analy Analysis sis and Speci Specificat fications ions of Soaps Soaps,, Synth Synthetics etics,, Deter Detergents gents and their Components. Current Curre nt editio edition n approv approved ed July 1, 2016. Published Published Augus Augustt 2016. Originally Originally approved approv ed in 1945. Last previous edition approved in 2009 as D820 – 93(2009 93(2009). ). DOI: 10.1520/D0820-93R16. 2 For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at
[email protected]. For Annual Book of ASTM Standards volume information, refer to the standard’s Document Summary page on the ASTM website.
D216 Metho D216 M ethod d of Test for Dis Distill tillatio ation n of Nat Natura urall Gas Gasoli oline ne (Withdrawn 1988) 3 D459 Terminology D459 Terminology Relating to Soaps and Other Detergents D875 Method for Calculating of Olefins and Aromatics in D875 Petrole Petr oleum um Dis Distill tillates ates fro from m Bro Bromin minee Num Number ber and Acid 3 Absorption (Withdrawn Absorption (Withdrawn 1984) D1193 Specification D1193 Specification for Reagent Water D1768 Test D1768 Test Method for Sodium Alkylbenzene Sulfonate in Synthetic Detergents by Ultraviolet Absorption D2357 for D2357 for Qualitative Classification of Surfactants by Infrared Absorption D2358 T D2358 Test est Method for Separation of Active Ingredient from Surfactant Surfa ctant and Synd Syndet et Compo Composition sitionss D3049 Test Met Method hod for Syn Synthet thetic ic Ani Anioni onicc Ing Ingred redien ientt by Cationic Titration 3. Terminology 3.1 Definitions: 3.2 The ter term m synthetic detergent in these test methods is defined in accordance with Terminology D459 D459,, as follows: 3.3 synthetic detergent— a detergent produced by chemical synthesis and comprising an organic composition other than soap. 3.4 For definitions definitions of other terms used in these test methods, methods, refer to Terminology D459 D459.. 4. Puri Purity ty of Reag Reagents ents and Materials Materials 4.1 Purity of Reagents— Reagent Reagent grade chemicals shall be used in all tests. Unless otherwise indicated, it is intended that all reagents shall conform to the specifications of the Committee on Analytical Analytical Reagent Reagentss of the Americ American an Chemica Chemicall Society Society,, where such specific specifications ations are availab available. le.4 Other grades may be used us ed,, pr prov ovid ided ed it is fir first st asc ascer erta tain ined ed th that at th thee re reag agen entt is of
3
The last app approv roved ed ver versio sion n of this historica historicall sta standa ndard rd is ref refere erence nced d on www.astm.org. 4 Reagent Chemicals, American Chemical Society Specifications, Americ American an Chemical Society, Washington, DC. For suggestions on the testing of reagents not Standards rds for Labor Laboratory atory listed liste d by the American Chemical Chemical Soci Society ety,, see Analar Standa Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia and National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville, MD.
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D820 − 93 (2016) sufficiently high purity to permit its use without lessening the accuracy of the determination. 4.2 Unles Unlesss otherwise indicated, indicated, references references to water shall be understood to mean reagent water conforming to Specification D1193.. D1193 MOISTURE AND OTHER MATTER VOLATILE AT 105°C (OVEN METHO METHOD) D) 5. Appar Apparatus atus 5.1 Dish— A porcelain or glass dish about 6 to 8 cm in diameter and about 2 to 4 cm in depth will be required. 6. Pro Procedu cedure re 6.1 Weigh 5 6 0.01 g of the sample in the dish, and dry to 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 is employed in these methods in place of the technically correct term mass.
FREE ALKALI OR FREE ACID 7. Reag Reagents ents 7.1 Ethyl Alcohol, Neutral (95 %) — Freshly Freshly boiled, reagent gra de de , et hy hyl al co cohol , 95 % or hi gh ghe r, r, ne ut utra l t o phenolphthalein, and containing only volatile denaturants, 95 mL,5 plus 5 mL of water. Phenolphtha hthalein lein Indic Indicator ator Solu Solution tion (10 g/l 7.2 Phenolp g/litr itre) e) — Dissolv Diss olvee 1 g of phenolph phenolphtha thalein lein in 50 mL of neutral neutral eth ethyl yl alcohol (95 %) and mix with 50 mL of water (see 7.1 7.1)).
8. Pro Procedu cedure re 8.1 Weig eigh h 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.
9.2 Stokes Flask, 100-mL, round-bottom (with the bottom blown out), out), sealed onto a 150-mL Erlenmeyer Erlenmeyer flask. flask. A diagra diagram m of the Stokes flask is shown in Fig. 1. 1. 9.3 Siphon, consisting of a two-hole rubber stopper fitted with small-diameter glass tubing as shown in Fig. 2. 2. 10. Reag Reagents ents Neutrall (95 %) — Freshl 10.1 Ethyl Alcohol, Neutra Freshly y boi boiled, led, reagen ag entt gr grad ade, e, et ethy hyll al alco coho hol, l, 95 % or hi high gher er,, ne neut utra rall to phenolphthalein, and containing only volatile denaturants, 95 mL,5 plus 5 mL of water.
10.2 Methyl Orange Indicator Solution (1 g/litre) — Dissolve Dissolve 0.1 g of methyl orange in water and dilute to 100 mL. 10.3 Petroleum Thee so solv lven entt us used ed sh shal alll be of th thee Petroleum Ether— Th pentan pen tanee typ type, e, con contain taining ing a min minimu imum m amo amount unt of iso isopen pentan tane, e, isohexane, and hexane, and boiling in the range 35 to 60°C. 6 Distillation test:A In i ti a l b o i l i n g p o i n t Dry flask end point Distilling under 54°C, min Distilling under 40°C, max Specifi Spe cific c gravi gravity ty at at 15.5/ 15.5/15. 15.5°C 5°C (60 (60/60 /60°F) °F) Color Doctor test Evap Ev apor orat atio ion n re resi sidu due, e, 10 100 0 mL mL,, ma max x Copper-strip corrosion testB Unsaturated compoundsC Residue in distilling flask Blotter-strip odor testD Aromatic compoundsE S ap o ni fi c at i on v a l u e
35 to 38°C 52 to 60°C 95 % 60 % 0.630 0.6 30 to to 0.660 0.660 water-white sweet 0.00 0. 001 11 g noncorrosive trace only permitted neutral to methyl orange odorless within 12 min no nitrobenzene odor less than 1.0 mg KOH/100 mL
A
The distillation test shall be made in accordance with Method D216 Method D216.. As a check on the evaporation evaporation residue, 250 mL of the petroleum ether ether and 0.25 g of stearin or other hard fat (previously brought brought to consta constant nt weight by heatin heating) g) when dried as in the actual determination determination (10.4 10.4)) shall not show an increase in weight exceeding 0.003 g. B The copper-strip copper-strip corrosion test shall be made by insert inserting ing a small polished polished copper strip into the petroleum ether in the distilling flask. There should be no appreciable darkening of the copper. C Unsaturated Unsatu rated compounds compounds shall be determ determined ined by the method for determining determining olefins described described in Method Method D875 D875..
6
J. T. Bak Baker er Analyzed Analyzed Reagent Reagent 926 9268, 8, or its equivalen equivalent, t, is sui suitab table le for thi thiss purpose.
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 borax in hot alcohol.
ANHYDROUS, SALT-FREE, SODA SOAP 9. Appar Apparatus atus 9.1 Extraction Cylinder 250-mL,, grad graduate uated, d, glas glasssCylinder,, 250-mL 1 stoppered, about 39 mm (1 ⁄ 2 in.) in diameter and about 35.5 cm (14 in.) in length.
5
Fischer Fisch er Scientific A962, A962, or its equiv equivalent alent,, is suita suitable ble for this purpose. Copyright by ASTM Int'l (all rights reserved); reserved); Tue Mar 7 12:22:54 EST 2017 2 Downloaded/printed by Univ des los Andes (Univ des los Andes) pursuant to License Agreement. No further reproductions authorized.
FIG.. 1 Sto FIG Stokes kes Flask Flask
D820 − 93 (2016) Stokes flask. Cool the cylinder or flask under tap water to a temperature temper ature not to exceed 25°C. Add 50 mL of petro petroleum leum ether 1 and an d all allow ow to st stan and d fo forr ⁄ 2 h with without out sha shakin king. g. Remo Remove ve 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 shaking the cylinder thoroughly each time. NOTE 3—If an emulsion appears at this point, it may be broken by the addition of 10 g of anhydrous Na 2SO4.
FIG.. 2 Sip FIG Siphon hon
D
Odor test: Immerse 1 in. of a strip of white unglazed blotting paper, approximately 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 acid (H2SO4, sp gr 1.84) and 10 drops of nitric acid (HNO3, sp gr 1.42) in a test tube, warm for 10 min, allow to cool for 30 min, transfer to a shallow dish, and dilute with water.
Phenolphtha phthalein lein Indic Indicator ator Solut Solution ion (10 g/li — 10.4 Phenol g/litre) tre) — Dissol Dis solve ve 1 g of phenolph phenolphtha thalein lein in 50 mL of neutral neutral eth ethyl yl alcohol (95 %) and then mix with 50 mL of water (see 10.1 10.1). ). Sodium um Hydr Hydroxid oxide, e, Stan Standar dard d Sol Solutio ution n (0.1 10.5 Sodi (0.1 N) Prepare and standardize a 0.1 N sodium hydroxide (NaOH) — Prepare solution.
10.6 Sodium Sulfate (Na2SO4), anhydrous.
11.3 Combin 11.3 Combinee the petrol petroleum eum ether extracts and wash with small portions of distilled water until the water washings are no long lo nger er aci acid d to me meth thyl yl or oran ange ge in indi dicat cator or so solu lutio tion. n. Dr Dry y th thee combined, combin ed, washed washed,, petro petroleum leum ether extracts with anhydrous anhydrous Na2SO4, and filter through paper into the original tared 250-mL beaker. Wash the separatory funnel with two small portions of petrol pet roleum eum ethe ether, r, filt filterin ering g and add adding ing the was washin hings gs to the beaker. 11.4 Eva 11.4 Evapor porate ate the pet petrol roleum eum eth ether er extr extract act on the stea steam m bath until about 1 mL remains. Then swirl manually until the last trace of solvent evaporates and the odor of petroleum ether is no longer perceptible. Cool in a desiccator and weigh as total fatty fat ty mat matter ter,, whi which ch is defi defined ned as fat fatty ty and rosin acids plus unsaponified and unsaponifiable fatty matter. 11.5 Disso 11.5 Dissolve lve the total fatty matter in 50 mL of neutral ethyl ethyl alcoholl (95 % v) with warmin alcoho warming. g. Add phenolphthal phenolphthalein ein indicator and titrate with 0.1 NaOH solution to a pink end point. 12. Calc Calculat ulations ions
10.7 Sulfuric Acid, Standard (0.5 (0.5 N) — Prepare Prepare and standardize a 0.5 N sulfuric sulfuric acid (H2SO4) solution.
12.1 Calcula Calculate te the percen percentage tage of anhyd anhydrous rous,, salt-fr salt-free, ee, soda soap as follows:
10.8 Sulfuric Acid (sp (sp gr 1.84) — Concentrated Concentrated sulfuric acid (H2SO4).
A 5 G 2 F
10.9 Sulfur Acid (1+1) — Gradua Gradually lly pou pourr 10 g of con concencentrated sulfuric acid (H2SO4) (sp gr 1.84) onto 10 g of cracked ice mad madee fro from m dis distill tilled ed wat water er,, gen gently tly swir swirling ling the mix mixing ing vessel; or gradually pour pour the acid down the sides of the mixing vessel ves sel into an equ equal al wei weight ght of wate waterr, swi swirlin rling g gen gently tly,, whi while le submersing the vessel in an ice bath. 11. Procedur Proceduree 11.1 Weigh 2 6 0.001 g of the sample into a tared 250-mL 11.1 beaker.. Add 25 mL of water and 25 mL of neutral ethyl alcohol beaker (95 %), and warm on the steam bath until solution is complete. Cool, Coo l, add 5 dro drops ps of meth methyl yl ora orange nge indicator indicator sol soluti ution, on, and titrate with 0.5 N H 2SO4 to a pink color. Add 5 mL of H 2SO4 (1+1) in excess. 11. 1.2 2 Trans Transfe ferr th thee co cont nten ents ts of th thee be beak aker er to a 25 2500-mL mL extraction cylinder or a Stokes flask, equipped with a siphon. Wash the beaker alternately with equal parts of hot water and hot ethyl alcohol (95 %), addin adding g the washin washings gs to the extraction cylinder or Stokes flask. Keep the total volume for extraction unde un derr 16 160 0 mL in th thee ex extr trac acti tion on cy cyli lind nder er,, or wi with thin in th thee 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
(1 )
G 5 @ ~~ VN 3 0.022! 1 E ! / W W # 3 100
where: = weight percen percentt of anhyd anhydrous, rous, salt-f salt-free, ree, soda soap, A G = weight percen percentt of of soda soda soap plus unsap unsaponifie onified d and and unsaponifiable fatty matter, F = weight percen percentt of unsap unsaponifie onified d and unsap unsaponifiab onifiable le fatty matter (Section 39 39)), = millilitr millilitres es of NaOH soluti solution on used in titratio titration n ( (11.5 11.5), ), V N = normalit normality y of NaO NaOH H so solution, lution, E = gra grams ms of extr extract act (11.4 11.4), ), and W = gr gram amss of sam sampl plee (11.1 11.1), ), and 0.022 0.0 22 = net gain gain in milliequ milliequiva ivalent lent weigh weightt from the the conver conver-sion of the fatty acid to the sodium salt by replacement of a proton with a sodium ion. ALCOHOL-SOLUBLE MA MATTER TTER 13. Reag Reagents ents Neutrall (95 %) — Freshl 13.1 Ethyl Alcohol, Neutra Freshly y boi boiled, led, reagen ag entt gr grad ade, e, et ethy hyll al alco coho hol, l, 95 % or hi high gher er,, ne neut utra rall to phenolphthalein, and containing only volatile denaturants, 95 mL5 plus 5 mL of water.
13.2 Ethyl Freshly boiled Ethyl Alco Alcohol hol,, Neu Neutra trall (absolute) — Freshly absolute ethyl alcohol, neutral to phenolphthalein. 5
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D820 − 93 (2016) 14. Procedur Proceduree
Na2 CO3 , % weight 5 106 VN/20 W
14.1 Weig 14.1 eigh h 2 6 0.00 0.001 1 g of the sam sampl plee in into to a 25 2500-mL mL beaker. Add 100 mL of neutral ethyl alcohol (95 %), cover the beaker, and heat on the steam bath with frequent stirring and maceration of the sample until completely disintegrated. Let settle and filter the supernatant liquid through a tared Gooch cruc cr ucib ible le wi with th a gl glas asss wo wool ol pa pad, d, wi with th su sucti ction on in into to a tar tared ed 300-mL Erlenmeyer flask, retaining as much of the residue as possible in the beaker. Repeat this extraction three times with 25-mL portions of hot neutral ethyl alcohol (95 %), each time retaini reta ining ng as muc much h of the residue residue as pos possib sible le in the beaker. beaker. Finally Fin ally,, eva evapor porate ate any rem remain aining ing alco alcohol hol and dis dissol solve ve the residue in the smallest possible quantity of hot water (5 mL if suffficient suf icient). ). Repre Reprecipita cipitate te the alcoh alcohol-in ol-insolub soluble le matter by slowly adding, while stirring vigorously, vigorously, 50 mL of neutral ethyl alcohol (absolute).
where: V = mill millilit ilitres res of stan standar dard d acid acid use used, d, N = no norm rmal ality ity of stan standa dard rd acid acid,, and and W = we weig ight ht of sa samp mple le (14.1 14.1), ), g
NOTE 4—Solution 4—Solution and repre reprecipitat cipitation ion of alcoho alcohol-ins l-insoluble oluble matter is necessary for complete separation from alcohol-soluble matter.
19. Procedur Proceduree
14.2 Hea 14.2 Heatt the solution solution to boi boiling ling on the steam bath, filter, filter, and tra trans nsfer fer the pre precip cipita itate te qu quant antita itativ tively ely to the Goo Gooch ch crucib cru cible, le, was washin hing g sev severa erall time timess with neu neutra trall eth ethyl yl alco alcohol hol (95 %). Evaporate the combined filtrate and washings in the Erlenmeyer flask on the steam bath, and then dry to constant weight at 105 6 2°C. Calculate total alcohol-soluble matter. 14.3 Reserv Reservee the flask and conten contents ts for the determination determination of free fatty matter (Section 37 (Section 37). ). Reserve the Gooch crucible and conten con tents, ts, wit withou houtt dry drying ing,, for the det determ ermina inatio tion n of matt matter er insoluble in water (Section 15 15)) and total alkalinity of matter insoluble in alcohol (alkaline salts) (Section 17 (Section 17). ). MATTER INSOLUBLE IN WATER 15. Procedur Proceduree 15.1 Wash 15.1 Wash the alco alcohol hol-in -insol solubl ublee matt matter er ret retain ained ed in the Gooch crucible (Section 14 14)) thoroughly with hot water until the washings are no longer alkaline to phenolphthalein. Reserve the filtrate for determination of total alkalinity of matter insoluble in alcohol (Section 17 (Section 17)). Dry the crucible and residue to constant weight at 105 6 2°C and calculate the percentage of matter insoluble in water. TOTAL ALKALINITY OF MATTER INSOLUBLE IN ALCOHOL (ALKALINE SALTS) 16. Reag Reagents ents 16.1 Hydrochlori P repar aree an and d sta stand ndar ardi dize ze a 1 N Hydrochloricc Acid— Prep hydrochloric acid solution. 16.2 Methyl Orange Indicator Solution (1 g/litre) — Dissolve Dissolve 0.1 g of methyl orange in water and dilute to 100 mL. 17. Procedur Proceduree 17.1 Titr Titrate ate the water solution obtained obtained in the determination determination of matter insoluble in water (Section 15 (Section 15)) with the standard 1 N hydrochlori hydro chloricc acid solution of of 16.1, 16.1, using using meth methyl yl ora orange nge as indicator. 17.2 Calculat Calculatee the alkalinity as sodium carbonate carbonate (Na2CO3) as follows:
(2)
SODIUM SILICATE 18. Reag Reagents ents 18.1 Hydrochloric Acid (sp (sp gr 1.19) — Concentrated Concentrated hydrochloric acid (HCl). 18.2 Hydrofluoric Acid (sp (sp gr 1.15) — Prepare Prepare a solution of hydrofluoric acid (HF) having a specific gravity of 1.15. 18.3 Sulfuric Acid (sp (sp gr 1.84) — Concentrated Concentrated sulfuric acid (H2SO4).
19.1 Whe 19.1 When n the material material contains contains no min mineral eral matter matter tha thatt is insoluble in water, ignite a portion of the sample containing not to exceed 0.2 g of silica (SiO 2) in a platinum dish (Note ( Note 5) 5) at a low temperature. When charred, extract the soluble salts with water, return the paper and charred residue to the dish, and complete the ignition. Unite the residue in the dish and the water extract, carefully acidify with HCl, and finally add the equivalent of from 5 to 10 mL of HCl in excess. The dish or casser cas serole ole con contain taining ing the sol solutio ution n sho should uld be cov covere ered d with a watch glass while adding acid, so as to avoid loss by spray. NOTE 5—When phosphates are present, a platinum dish should not be used.
19.2 When the material material contains mineral mineral matter insoluble insoluble in water, or a determ water, determination ination of highe highest st accura accuracy cy is not necessary, necessary, take a portio portion n of the solution after titrating the matter insoluble in alcoho alcoholl (Sectio (Section n 17 17)) containing not more than 0.2 g of SiO 2 and add 5 to 10 mL of HCl. 19.3 Evaporate the acidified solution obtained in accordance with 19.1 with 19.1 or or 19.2 19.2 (washing (washing off and removing the cover glass if used) to dryness on a steam bath or hot plate at a temperature not exceeding 120°C. Cool, moisten with HCl and let stand 5 to 10 min, breaking breaking up all lumps with a stirring rod. Add about 25 mL of hot water. Heat a few minutes and filter through a small ashless paper. Wash thoroughly with hot water. 19.4 Eva 19.4 Evapor porate ate the filtrate filtrate to dry drynes nesss and proceed proceed as described in 19.3 in 19.3,, filtering on a second paper. Carefully ignite the two papers and contents in a weighed platinum crucible, first at a low temperature until the paper is consumed, then over a blas bl astt lam lamp. p. Co Cool ol in a de desic sicca cato torr, we weig igh, h, an and d re repe peat at un until til constant weight is obtained. 19.5 19. 5 If ext extrem remee accu accurac racy y is des desire ired, d, moi moiste sten n the wei weighe ghed d contents of the crucible with water, add 10 mL of HF and 4 drops of concentrated H 2SO4, and evaporate to dryness over a low flame. Ignite at the temperature of the blast lamp for about 2 min, cool in a desiccator, and weigh. 20. Calc Calculat ulation ion 20.1 Calcu 20.1 Calcula late te th thee so sodi dium um si sili lica cate te ha havi ving ng th thee ra rati tio o 1 Na2O:3.25 SiO2 as follows:
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D820 − 93 (2016) Sodium silicate, % w 5 ~ A 2 B ! 3 1.308
(3)
where: A = gram gramss of ig igni nited ted residu residuee be befo fore re tr treat eatmen mentt wi with th HF (19.4 19.4)), and ignited residu residuee after after treatment treatment with HF (19.5 (19.5). ). B = grams of ignited PHOSPHATES 21. Appli Applicati cation on 21.1 This test method is applicable applicable to any species of alkali metal phosphates free of interfering ions. This test method can be us used ed fo forr th thee an analy alysis sis of so soap ap an and d sy synt nthe hetic tic de dete terg rgen entt builders if the sample is properly prepared (see Section 26 26). ). This test method does not apply when the level of phosphate present is equivalent to or less than 2 % P 2O5. 22. Summa Summary ry of Test Method 22.1 22 .1 Al Alll of th thee ph phos osph phate ate pr pres esen entt is co conv nver erted ted,, by ac acid id hydrolysis, to the ortho form and titrated between pH 4.3 and 8.8 with NaOH solution. 23. Interfere Interferences nces 23.1 Heavy 23.1 Heavy me meta tals ls su such ch as ir iron on,, al alum umin inum um,, ca calc lciu ium, m, magnes mag nesium ium,, etc. etc.,, tha thatt wil willl pre precip cipitat itate, e, eith either er as ins insolu oluble ble phos ph osph phate atess or hy hydr drox oxid ides es,, be befo fore re th thee up uppe perr en end d po poin intt is reached reac hed,, wil willl inte interfe rfere. re. Int Interf erfere erence nce als also o occ occurs urs if bor borates ates,, sulfites,, carbon sulfites carbonates, ates, or other buffering buffering materials are prese present. nt. Thee las Th lastt tw two o co comp mpou ound ndss an and d so some me of th thee bo bora rate te wi will ll be expelled during the acid hydrolysis boil. Borate is removed by conver con versio sion n to met methyl hyl bor borate ate and sub subseq sequen uentt vol volatil atilizat ization ion.. Ammonia or other weak bases also will interfere. The most common com mon inte interfe rferen rence ce is fro from m sil silicic icic acid acid.. Exp Experi erimen mentt and experience in analysis of spray-dried synthetics have shown that unless the ratio of the percen percentage tage of SiO2 to the percentage of P 2O5 approaches or exceeds 0.2, the interference by silicates will be so slight that it may be neglected. Larger amounts must be de dehy hydr drat ated ed as di dire rect cted ed,, bu butt ne need ed no nott be re remo move ved d by filtration during preparation of the sample. 24. Appar Apparatus atus
25.2.1 Methyl Orange Solution (0.5 g/litre) — Dissolve Dissolve 0.05 g of methyl orange in water and dilute to 100 mL. Phenolphthalei hthalein, n, Alcoho Alcoholl Solutio Solution n (5.0 g/li 25.2.2 Phenolp g/litre tre)) — Dissolve 0.50 g of phenolphthalein in alcohol (50 %) and dilute to 100 mL with alcohol. 25.2.3 Thymol Blue Solution (0.4 g/litre) — Dissolve Dissolve 0.04 g of thymol blue in water and dilute to 100 mL. 25.2.4 Methylene Blue Solution (1.0 g/litre) — Dissolve Dissolve 0.10 g of methylene blue in water and dilute to 100 mL. 25.2.5 Alcohol (90 %) — Alcohol Alcohol (90 %) prepared from alcohol conforming to Formula No. 3A or No. 30 of the U.S. Bureau of Internal Revenue. Mix the solutions in the following proportions: Methyl orange solution P h e n o l p h th a l e i n s o l u ti o n Thymol blue solution M e t h y l e n e b l u e s o l u ti o n Al c oh ol
32 32 8 4 24
mL mL mL mL mL
The ind indivi ividua duall com compon ponents ents are sta stable ble ind indefin efinitel itely y. The mixed indicator should be prepared at least weekly. In practice, 3 mL of this mixed indicator are used in a final volume of approximately 250 mL of solution to be titrated. The lower end point is taken as the first change from gray to a definite green; the upper end point is the change from pink to a bright purple. Sodium m Hydr Hydroxide, oxide, Stand Standar ard d Soluti Solution on (0.5 25.3 Sodiu (0.5 or 1. 1.0 0 N) — Prepare Prepare a 0.5 or 1.0 N carbonate-free solution of sodium hydroxide (NaOH) and standardize accurately.
25.4 Sodium Hydroxide Solution (1+1) — Dissolve Dissolve sodium hydroxide (NaOH) in an equal weight of water. When using, decant the solution from the settled carbonate. A more dilute solution may be used. NaOH solutions must be protected from carbon dioxide (CO2) contamination. 26. Pre Prepara paration tion of Sampl Samplee Solut Solutions ions 26.1 Commer Commercial cial sodium or potassium phosphates phosphates need no special preparation except solution in water. Weigh a portion of the well-mixed sample to the nearest 0.001 g, transfer directly to a 400-mL beaker, and dissolve in about 100 mL of water. Neutralize to litmus paper with HCl (sp gr 1.19) and add 10 mL excess. The optimum size of sample is given by the formula: Grams of sample 5 ~ N 3 280! / P
(4 )
24.1 Electrometric Titration Apparatus, equipped with glass and calo calomel mel elec electro trodes des.. Any standard standard pH met meter er,, cap capabl ablee of perfor per formin ming g titr titratio ations ns accu accurat ratee to 60. 0.1 1 pH an and d ac accu cura rate tely ly standardized at pH 4.0 and 8.0 is suitable.
where: N = norm normali ality ty of the NaOH solu solutio tion n to be used used in th thee titration, titratio n, and = per percen centag tagee of P2O5 expected in the sample. P
Burners, rs, suitable for heating the sample to ap24.2 Gas Burne proximately 550°C.
26.2 Soa 26.2 Soap p pro produc ducts ts may be ana analyze lyzed d by using the filtr filtrate ate from the silicon dioxide (SiO 2) determination. Use care not to exceed the sample weight prescribed in 26.1 in 26.1.. Alternatively the sample may be prepared as described in 26.3 26.3..
24.3 Muffle Furnace, with suitable pyrometer and controls for maintaining temperatures up to 550°C. 24.4 Motor Stirrer, air or electric. 25. Reag Reagents ents 25.1 Hydrochloric Acid (sp gr 1.19) — Concentrated Concentrated hydrochloric acid (HCl). 25.2 Mixed Indicator (optional) (optional) — Prepare Prepare the following solutions:
26.3 Built synthetic synthetic detergent detergent samples are treated by ashing. ashing. Weigh a sample of suitable size (but not to exceed 10 g) to the nearest 0.001 g. When the expected percentage of P 2O5 in the sample is known, the equation in 26.1 26.1 may may be used to calculate a su suit itab able le sa samp mple le we weig ight ht.. Pl Place ace th thee sa samp mple le in a 40 4000- mL high-s hig h-silic ilicaa gla glass ss bea beaker ker,, or a new new,, wel well-g l-glaze lazed d por porcela celain in or silica evaporating dish or large crucible and ignite gently over a low gas burner until most of the volatile combustible matter
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D820 − 93 (2016) is burned off. Use care so that the sample is not heated to above 550°C with the gas burner. Transfer to a muffle, operated at not over 550°C, for 10 to 15 min. The ignited residue need not be free from carbon and usually is of a grayish color. Cool and add cautiously cautiou sly 10 mL of HCl. Evapo Evaporate rate to dryn dryness ess on open steam. If the ratio of the percentage of SiO 2 to the percentage of P2O5 appr ap proa oach ches es or ex excee ceeds ds 0. 0.2 2 or is un unkn know own, n, de dehy hydr drat atee th thee silicates completely by cooling the sample and repeating the HCl addition and evaporation two additional times. After the third evaporation, continue to heat the residue for an additional 15 to 20 min af afte terr dr dryn yness ess is at attai taine ned d to en ensu sure re co comp mplet letee dehydration of SiO 2. After the sample appears dry, last traces of water or HCl may be removed in a 110 to 120°C oven, if desir de sired ed,, in th this is st step ep.. Co Cool ol th thee sa samp mple le an and d tr tran ansf sfer er in into to a 400-mL beaker using distilled water and proceed as in 26.3.1 or 26.3.2 or 26.3.2.. 26.3.1 26.3. 1 If the sample contains contains perborate perborate or borate borate,, evaporate to dryness on a steam bath, add about 200 mL of methanol, 10 mL of HCl and two or three hollow glass beads. Partially cover the beaker with a watch glass and boil down to a volume of abou ab outt 20 mL mL.. (T (The he bo boili iling ng ti time me mu must st be at lea least st 30 min.) Evaporate down to less than 10 mL on a steam bath under a stream of nitrogen or clean, dry air. Proceed as described in Section 27 Section 27.. 26.3.2 26.3. 2 If the sample is known to be free from perborate perborate and borate,, add distilled water to make a total of about 90 mL. Add borate 10 mL of HCl and proceed as in Section 27 27.. 27. Procedur Proceduree 27.1 Each solution 27.1 solution in a 400 400-mL -mL beaker beaker,, pre prepar pared ed as described in 26.1 26.1,, should have a volume of about 100 mL and contain an excess of at least 10 mL of HCl (sp gr 1.19). Cover with a watch glass and boil gently for a minimum of 30 min. Up to 60 min may be necessary for phosphates of the glass type. All phosphate must be in the ortho form. Cool to room temperature (20 to 30°C). 27.2 Dilu 27.2 Dilute te to 200 mL, place on an ele electro ctrometr metric ic titr titratio ation n stand (Note 6), 6), and neutralize to a pH of 4.3. Most of the neutralization may be made with NaOH solution (1+1), but finall adj fina adjust ustmen mentt sho should uld be mad madee wit with h the stan standar dard d NaO NaOH H solution (0.5 or 1.0 N ) to be used in the titration. Cool again, if necessary, to maintain the temperature below 30°C. Titrate carefully to the upper end point (pH 8.8) recording the titration between end points (T ). ). NOTE 6—The mixed indicator may be used for this titration but with some small sacrifice of accuracy. If the samples have been prepared by the ignition method, they must be filtered and the paper washed thoroughly, after the acid hydrolysis, as particles of carbon obscure the visual end point. The color changes can be checked by comparison with pH meter readings to acquire familiarity with the exact shade required. For greatest accuracy, titration with a pH meter is recommended.
28. Calc Calculati ulation on 28.1 Calculat Calculatee the percentage of total P2O5 as follows: W Total P 2 O 5 , % weight 5 ~ TN 3 7.098! / W
N = norma normality lity of of the NaOH soluti solution, on, and and W = grams grams of sample sample in the the sample sample solutio solution. n.
PHOSPHORUS (COLORIMETRIC METHOD USING MOLYBDENUM MOL YBDENUM BLUE) 29. Summ Summary ary of Test Test Method 29.1 29. 1 The sample sample is dis dissol solved ved in wat water er and the pho phosph sphates ates hydrolyze hydrol yzed d to ort orthop hophos hospha phate te wit with h min minera erall acid acid.. A dil dilute uted d aliquot aliq uot of the hydrolyz hydrolyzed ed sam sample ple is reac reacted ted with a sin single gle-soluti sol ution on mol molybd ybdate ate rea reagen gentt to for form m the mol molybd ybdenu enum m blu bluee complex comple x with the ortho ortho-pho -phosphate sphate present. After extrac extraction tion into in to iso isobu butan tanol ol to re remo move ve an any y in inter terfe fere renc ncee fr from om pr prod oduc uctt colorants or turbidity, the molybdenum blue complex is measured colorimetrically. 30. Scop Scopee 30.1 This procedure procedure must be used to determine the level of phosphate present in detergents when the level present is equal to or less than that equivalent to 2 % P2O5. Results are reported as percent weight P. 31. Reag Reagents ents 31.1 31. 1 The sin singlegle-sol solutio ution n mol molybd ybdate ate rea reagen gentt is pre prepar pared ed from solutions of sulfuric acid, ammonium molybdate, potassium antimonyltartrate, and ascorbic acid as follows: 31.1.1 Solu Cautiously sly add add,, with Solutio tion n A, Su Sulfu lfuri ricc Ac Acid id— — Cautiou cooling, 140 mL of concentrated sulfuric acid (H 2SO4, sp gr 1.82) to 900 mL of water. Cool to room temperature. 31.1.2 Solution B, Ammonium Molybdate— Dissolve Dissolve 15.0 g of ammonium ammonium molybdate in 500 mL of water. water. Store in the dark. 31.1.3 Solution C, Ascorbic Acid— Dissolve Dissolve 13.5 g of ascorbic acid in 250 mL of water. water. Store at 4°C. Discard after 1 week. Potassium ium Antimo Antimonyltar nyltartrate— trate— Dissolve 31.1.4 Solution D, Potass 0.35 g of potassium antimonyltartrate (C 4H4KO7Sb) in 500 mL of distilled water. Store at 4°C in the dark. 31.2 31 .2 Mi Mix x th thor orou ough ghly ly 12 125 5 mL of So Solu lutio tion n A, 50 mL of Solution B, 50 mL of Solution Solution Solution C, and 25 mL of Solution Solution D. The resulting single-solution molybdate reagent should be yellow in col color or.. Allow to rea reach ch roo room m temp tempera eratur turee pri prior or to use use.. A greenish or blue color indicates phosphate contamination, in which wh ich cas casee th thee so solu lutio tion n sh shou ould ld be di disca scard rded ed.. Th Thee sin singl gleesolution molybdate reagent must be prepared fresh daily. The individual solutions are stable as stated above. Add solutions in the order specified “A” “A” 1st, “B” 2nd, “C” 3rd, and “D” 4th. 31.3 Potassium dihydrogen phosphate (anhydrous), reagent grade. 32. Cali Calibrat bration ion 32.1 A pho 32.1 phosph sphate ate sto stock ck sol solutio ution n for cali calibra bratio tion n may be prepared by dissolving in a 1000-mL volumetric flask 0.4394 6 0.0002 g of potassium dihydrogen phosphate (anhydrous) (KH PO4) which has been previously dried at 105°C for 1 h. This stock solution contains ortho-phosphate equivalent to 100 µg P/mL. 2
(5 )
where: millilitres es of NaOH solutio solution n required required for titratio titration n of the T = millilitr sample,
32.2 Make a dilute stock solution solution containing containing 1.00 µg P/ mL by pipeting 10 mL of the original stock solution into a 1-L volumetric flask and diluting to volume with water.
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D820 − 93 (2016) 32.3 Tra Transfer nsfer by pipet 10, 20, 30, 40, and 50-mL aliquots aliquots of the dilute stock solution to separate 250-mL separatory funnels containing contain ing about 50 mL of water. Add additional additional water to each separatory funnel to bring the total volume to 100 mL. Use as a blank 100 mL of water added to an additional separatory funnel. 32.4 To each calibration calibration point and the blank add 20 mL of mixed reagent from a dispensing flask or graduated cylinder; stopper and shake the separatory funnel vigorously to mix well. Let stand for 10 min but no longer than 15 min. (The formation of the molybdenum blue complex is not instantaneous; however color formation is essentially complete in the first 2 to 3 min.) Add 40 mL of isobutanol using a graduated cylinder and shake for 60 6 10 s. Let stand 5 min but no longer than 10 min to al allo low w th thee la laye yers rs to sep separ arate ate.. Dr Drain ain of offf an and d di disc scar ard d th thee aqueous layer; drain the isobutanol layer into a 50-mL volumetric flask, washing down the walls of the separatory funnel with 5 mL of ethanol. ethanol. Dilute the extract to volume with ethanol and mix well. Determine the absorbance of the extract at 690 nm in a 1-cm spectrophotometric cell versus distilled water as a refer reference. ence. Absor Absorbance bance measurement measurement should be made within 1 h of color development. 32.5 Plo 32.5 Plott a cali calibra bratio tion n cur curve ve of abs absorb orbanc ancee valu values es det deterermined versus micrograms of P present where the water blank represents 0 and the 10, 20, 30, 40, and 50-mL aliquots of dilute stock solution represent 10, 20, 30, 40, and 50 µg of P, respec res pective tively ly.. The cur curve ve sho should uld be line linear ar with an inte interce rcept pt of + 0.01 − 0.03 absorbance units. 33. Procedur Proceduree for Detergent Samples Samples 33.1 Usi 33.1 Using ng the fol follow lowing ing tab table, le, weig weigh h out accu accurat rately ely to 60.001 g a sample of well mixed, riffled, detergent material into a 50-mL beaker: Esti Es tima mate ted d % We Weig ight ht P
Samp Sa mple le We Weig ight ht,, g
Vol olum umet etri ric, c, mL
Aliq Al iquot uot,, mL
0 to 1 1 to 2
1 0. 0 1 0. 0
10 0 1 00 0
5 10
Transfer to a 1-L volumetric flask, adding water to a total volume of approximately 500 mL. Carefully, and with gentle mixing, add 50 mL of concentrated sulfuric acid to the sample solutio sol ution. n. If carbonates are pr pres esen ent, t, tak takee ca care re du duri ring ng ac acid id addition so that evolution of CO 2 does not cause the sample to foam out of the neck of the flask. After acid addition, rinse down the neck of the flask with water, mix gently, and place on a hot steam bath for 1 h. Remove, cool, and dilute to volume with water. Mix well. Dilute the hydrolyzed sample solution by pipeting an aliquot into a volumetric flask. Use an aliquot and flask size as specified in the table above as a guide. Other comb co mbin inat atio ions ns of ali aliqu quot otss an and d fla flask sk siz sizes es ma may y be us used ed as desired. The diluted sample solution should contain about 20 to 40 µg P/10 mL (2 to 4 µg/mL). Mix well. Pipet 10 mL of the dilu di luted ted sa samp mple le so solu lutio tion n in into to a 25 2500-mL mL se sepa para rato tory ry fu funn nnel el containing contain ing 90 mL of water. water. Add 2 to 3 drop dropss of phenolphthalein phenolphthalein indicator solution and 3 to 4 drops of 50 % NaOH solution. Add 1 N H2SO4 dropwise until the sample is just colorless. Proceed as described in 32.4 in 32.4,, starting with “Add 20 mL of the mixed reagent from a dispensing flask or .................”
34. Calc Calculat ulations ions 34.1 Calc 34.1 Calcula ulate te the percent percent wei weight ght P pre presen sentt in the samp sample le from fro m the sam sample ple wei weight ght,, dil diluti ution on and aliq aliquot uot vol volume umes, s, and micr mi crog ogra rams ms of ph phos osph phor orus us fo foun und d in th thee fin final al ali aliqu quot ot as determined from the calibration curve of phosphorus as follows: A 5 ~ B 3 V ! / ~ W 3 C 3 100!
(6 )
where: = weight percen percentt of phosp phosphorus horus,, A = microg micrograms rams of phosph phosphorus, orus, (fou (found nd using using calibrat calibration ion B curve), V = vol volume ume,, mL, (se (seee 33.1 33.1), ), W = samp sample le weig weight, ht, g, and = aliquot, aliquot, mL. C 34.2 Round off off and report data to two decimals; report report any value less than 0.005 % w P as 0.00 % w; report 0.007 % w P as 0.01 % w P, etc. Duplicate runs which agree within 8.5 % relative are acceptable for averaging (95 % confidence level).7 34.3 To convert convert from % w P to % w P2O5, multiply the % w P by 2.29. Repeatabilit bilityy (Sin (Single gle Anal Analyst)— yst)— The coef 34.4 Repeata coeffficien icientt of vari va riat atio ion n of re resu sult ltss (e (eac ach h th thee av aver erag agee of du dupl plic icat atee determ det ermina ination tions), s), obt obtain ained ed by the sam samee ana analys lystt on dif differ ferent ent days da ys,, wa wass es estim timat ated ed to be 2. 2.9 9 % re relat lativ ivee at 14 de degr grees ees of freedo fre edom. m. Two suc such h ave averag rages es sho should uld be con consid sidere ered d sus suspec pectt (95 % con confide fidence nce lev level) el) if the they y dif differ fer by mor moree tha than n 5.7 % relative. Reproducibility (Multilaboratory)— The 34.5 Reproducibility The coef coeffficient of vari va riat atio ion n of re resu sult lts, s, (e (eac ach h th thee av aver erag agee of du dupl plic icat atee determinations), obtained by analysts in different laboratories, hass be ha been en es estim timate ated d to be 4. 4.3 3 % re relat lativ ivee at 12 de degr gree eess of freedo fre edom. m. Two suc such h ave averag rages es sho should uld be con consid sidere ered d sus suspec pectt (95 % confidence level) if they differ by more than 13.1 % relative.
UNSAPONIFIED AND UNSAPONIFIABLE FATTY MATTER NOTE 7—In the case of superfatted soaps, free fatty acids, which are the superfatt superf atting ing age agents nts in hig highes hestt per percen centag tage, e, plu pluss this uns unsapo aponifi nified ed and unsaponifia unsap onifiable ble matter matter,, const constitute itute the major portion of the super superfattin fatting g agents used.
35. Summ Summary ary of Test Test Method 35.1 Unsap Unsaponifie onified d and unsap unsaponifia onifiable ble fatty matter plus free rosin ros in and free fat fatty ty acid acidss in the alc alcoho ohol-s l-solu oluble ble matter are extracted with petroleum ether from a 50/50 volume percent solution of ethanol and water. The acids are then removed with NaOH wash (38.3 38.3). ). If it is desired to include these acids in a calculation for free fatty matter, proceed to Section 40 40.. 36. Appar Apparatus atus Extraction tion Cylinder or Stokes Flask, and Siphon— See 36.1 Extrac Section 9. 7
Data supporting the precision statements are available at ASTM Headquarters. Request RR:D12-1006.
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D820 − 93 (2016) 37. Reag Reagents ents 37.1 Ethyl Alcohol, Neutral (95 %) — Freshly Freshly boiled ethyl alcohol, 95 % or higher and neutral to phenolphthalein, (see 7.1). 7.1 ).
where: F = weigh weightt percen percentt of unsap unsaponified onified and unsap unsaponifia onifiable ble fatty matter, E = wei weight ght of dri dried ed pet petrol roleum eum eth ether er extr extract act (38.4 38.4), ), and W = we weig ight ht of of samp sample le in in gra grams ms (14.1 14.1). ).
37.2 Petroleum Ether— See 10.3 See 10.3.. 37.3 Phenolphthalein Indicator— Prepare Prepare a 1 % solution in neutral ethyl alcohol (95 %) (see 36.1 36.1). ). 37.4 Sodium (0.2 N) — Sodium Hyd Hydro roxide xide,, Sta Standa ndard rd Sol Solutio ution n (0.2 Prepare and standardize a 0.2 N sodium hydr hydroxide oxide (NaOH (NaOH)) solution.
40. Fre Freee Fatty Matter Matter 40.1 The free fatty matter is calculated calculated as the percen percentage tage of unsaponified and unsaponifiable fatty matter (see 39.1 (see 39.1)) plus the weight percentage of free rosin and free fatty acids (see Section 8). CHLORIDES IN ALCOHOL-SOLUBLE MATTER
37.5 Sodium Sulfate, (Na2SO4), anhydrous.
41. Reag Reagents ents
38. Procedur Proceduree 38.1 Dissol Dissolve ve the alcoho alcohol-solu l-soluble ble matter obtained in accordance with Section 14 Section 14 in a mixture of 25 mL of water and 25 mL of neu neutral tral ethy ethyll alco alcohol hol (95 %), war warmin ming g if nec necessa essary ry.. Trans Tr ansfer fer the sol solutio utions ns to a 250 250-mL -mL extractio extraction n cyl cylind inder er or a Stokes Sto kes flask flask,, equ equipp ipped ed wit with h sip siphon hons. s. Wash the Erl Erlenm enmeye eyerr flask alternately with equal parts of hot water and hot neutral ethyll alco ethy alcohol hol (95 %), add adding ing the was washin hings gs to the ext extrac raction tion cylinder or Stokes flask. Keep the total volume for extraction unde un derr 16 160 0 mL in th thee ex extr trac acti tion on cy cyli lind nder er,, or wi with thin in th thee constricted portion of the Stokes flask. Wash the Erlenmeyer flask with a small amount of petroleum ether to remove any traces trac es of fatty matter and add to the extractio extraction n cyli cylinde nderr or Stokes flask. 38.2 38 .2 Cool Cool th thee cy cyli lind nder er or fla flask sk un unde derr ta tap p wa wate terr to a temperature not to exceed 25°C. Add 50 mL of petrol temperature petroleum eum ether and shake. Draw off the petroleum ether layer as closely as possible, by means of a glass siphon, into a separatory funnel of 500-mL capacity capacity.. Repeat the extrac extractions tions six more times with petroleum ether, using 50-mL portions, shaking the cylinder thoroughly each time. NOTE 8—If an emulsion appears at this point, it may be broken by adding 10 g of anhydrous sodium sulfate (Na 2SO4).
38.3 Com 38.3 Combin binee the petr petrole oleum um eth ether er extr extracts acts and was wash h fou fourr times with 10-mL portions of 0.2 N NaOH solution adding the washings to the alcoholic solution which shall be reserved for the determination of chlorides (Section 40 40). ). Finally, wash the petroleum ether extract with small portions of water until the waterr was wate washin hings gs are no lon longer ger alka alkalin linee to phe phenol nolpht phthal halein ein.. Transfer Tran sfer the washed petroleum petroleum ether extract to a tared 300-mL Erlenme Erle nmeyer yer flask flask,, was washin hing g the sep separa arator tory y fun funnel nel with two small portions of petroleum ether. 38.4 Evapo Evaporate rate on a steam bath until about 1 mL remains. Swirl manually until all solvent is evaporated and the odor of petroleum ether is no longer perceptible. Cool in a desiccator and weigh.
41.1 Calcium Carbonate (CaCO3) chloride-free. 41.2 Magnesium Nitrate Solution (200 g/L) — Dissolve Dissolve 200 g of chloride-free magnesium nitrate (Mg(NO 3)2·6H2O) in 1 L of water. 41.3 Potassium Chromate Indicator Solution— Dissolve Dissolve 5 g of chlor chloride-fr ide-free ee potass potassium ium chrom chromate ate (K2CrO4) in water and add 0.1 N AgNO3 solutio solution n unt until il a slig slight ht red pre precip cipitat itatee is produced. Filter the solution, and dilute the filtrate to 100 mL. 41.4 Silver Nitrate, Standard Solution (0.1 N) — Prepare Prepare and standardize a 0.1 N silver silver nitrate (AgNO3) solution. 42. Procedur Proceduree 42.1 To the alcoho alcoholic lic solution remaining remaining after the determination of fatty matter (Section 38 38), ), add 15 mL of Mg(NO 3)2 solu so lutio tion. n. He Heat at on th thee ste steam am ba bath th un until til th thee pr preci ecipi pitat tatee is coagulated, filter, and wash with water into a 500-mL beaker. 42.2 Add 1 mL of K 2CrO4 indicator for every 100 mL of solution. Titrate the solution containing the sample with 0.1 N AgNO3 solution until the red color formed by each drop begins to disappear more slowly upon stirring, showing that most of the chloride has been precipitated. 42.3 Prepa Prepare re a blank by adding to another 500-mL 500-mL beaker the same volume of distilled water, Mg(NO3)2 solution, and K CrO4 indicator present in the beaker containing the sample. Add enough calcium carbonate (CaCO 3) to the blank, so that the turbidity in both solutions appears to be the same when they are swi swirle rled. d. Usi Using ng the bla blank nk for compariso comparison, n, con contin tinue ue the titration of the solution containing the sample until a faint but distin dis tinct ct cha change nge of col color or occ occurs urs.. At the end poi point nt the color should not be dark, just distinctly different (reddish yellow) from that of the blank containing no silver chromate. 2
42.4 Add to the blank blank enough enough 0.1 N AgNO AgNO3 solution so that thee co th colo lors rs of th thee tw two o so solu lutio tions ns ex exact actly ly ma match tch;; th this is is th the“ e“ blank” titration required to produce the end point.
39. Calc Calculati ulation on
43. Calc Calculat ulation ion
39.1 Calculate the percentage of unsaponified and unsaponifiable fatty matter as follows:
43.1 Calc 43.1 Calcula ulate te the per percen centag tagee of chl chlori orides des (as NaC NaCl) l) in alcohol-solu alcoho l-soluble ble matter as follo follows: ws:
F 5 E 3 100/ W
(7)
C 5
@ ~ V
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1
2
V 2 ! N 3 0.0585# / W W 3 100
(8)
D820 − 93 (2016) where: = weig weight ht percen percentt of chlori chloride dess (a (ass Na NaCl) Cl) in al alco coho hollC soluble matter, V 1 = mill millilit ilitres res of AgN AgNO O3 solution required for titration of the sample (42.3 42.3)), millilit ilitres res of AgN AgNO O3 solution required for titration of V 2 = mill the blank (42.4 42.4)), N = nor normali mality ty of the AgN AgNO O3 solution, and W = weig weight ht of sam sample ple,, g. ROSIN (McNICOLL METHOD)8
44.1 The 44.1 The ap appa para ratu tuss re requ quir ired ed co cons nsis ists ts of a gl glas asss fla flask sk connec con nected ted,, pre prefer ferabl ably y by a gro ground und-gl -glass ass join joint, t, to a refl reflux ux condenser. 44.1.1 Esterification Esterification Flask— A 150-mL flask of either the round-bottom or Erlenmeyer type shall be used. 44.1.2 Reflux Condenser— Any Any suitable water-cooled, glass reflux condenser may be used. 45. Reag Reagents ents 45.1 Naphthalene- β -Sulfonic Dissolve 40 g -Sulfonic Acid Solut Solution— ion— Dissolve of East Eastman man grade or equ equiva ivalent lent reagent reagent in 1 L of abs absolu olute te methyl alcohol. Phenolphthalein lein Indica Indicator tor Solut Solution— ion— Prep 45.2 Phenolphtha P repar aree a 1 % solution in neutral ethyl alcohol (95 %) (see 10.1 10.1)).
45.3 Potass Potassium ium Hyd Hydro roxid xide, e, Sta Standa ndard rd Alco Alcohol holic ic Sol Soluti ution on (0.2 N) — Accurately Accurately standardize standardize a 0.2 N solution of potassium hydroxide (KOH) in neutral ethyl alcohol (95 %) (see 10.1). 10.1). Due to volatility of alcohol, this solution should be restandardized frequently. 46. Procedur Proceduree 46.1 Preparation of Total Fatty Matter— Prepare Prepare total fatty matter for the ros matter rosin in dete determi rminat nation ion in acco accorda rdance nce with the extraction procedure described in 11.1 – 11.4, 11.4 , using enough sample to yield approximately 5 g of total fatty matter. 46.2 Esterification and Titration— Weigh Weigh 2 6 0.001 g of the total fatty matter into the esterification flask. Add 25 mL of β-sulfonic acid solution. Add a few glass beads to naphthalene-β naphthaleneensure smooth boiling, attach the reflux condenser, and boil for 30 min; also, run run a blank test using 25 mL of the reagent. reagent. At the end of the boiling period cool the contents of the flask, add 0.5 mL of phenolphthalein indicator, and titrate immediately with 0.2 N alcoholic KOH solution. 47. Calc Calculati ulations ons 47.1 Calculat Calculatee the results as follows (Note 9): 9):
R
s
5 R 2 3 1.064
where: R = weight weight percent percent of rosin rosin in total total fatty fatty matter matter,, R1 = corre corrected cted weight weight percent percent of of rosin in total total fatty matter matter (Note 10), 10), R2 = weigh weightt percent percent of rosin rosin on on basis of original original sample, sample, R = weigh weightt percent percent of rosin rosin-soda -soda soap on basis basis of origin original al sample, V 1 = mill millilit ilitres res of KOH solutio solution n required required for titrati titration on of sample, V 2 = mill millilit ilitres res of KOH solutio solution n required required for titrati titration on of blank, N = norma normality lity of KOH soluti solution, on, grams ms of sam sample ple (46.2 46.2), ), W 1 = gra = wei weight ght per percen centt of total fatty total fatty matter, B = gra grams ms of ext extrac ractt (11.3 11.3)), and E W 2 = gr gram amss of sample sample us used ed in pr prep epar arat atio ion n of total total fa fatty tty matter ( matter (46.1 46.1). ). NOTE 9—In all cases where the rosin content is found to be less than 5 %, the actual presence or absence of rosin should be checked qualitatively by the Liebermann-Storch test, as follows: Transfer Tran sfer 1 to 2 mL of the sample of fatty acids plus fatty matter to a test tube, add 5 to 10 mL of acetic anhydride, anhydride, and warm on a steam bath. bath. After cooling, pour 1 to 2 mL into a white porcelain dish and allow a drop or two of sulfuric acid (H2SO4, sp gr 1.53) to run down the side of the vessel. (The H2SO4 (sp gr 1.53) is prepared by diluting 34.7 mL of H2SO4 (sp gr 1.84 1. 84)) wi with th 35 35.7 .7 mL of wa wate terr.) If ro rosi sin n is pr pres esen ent, t, a fu fugi giti tive ve vi viol olet et coloration changing to a brownish tinge is immediately produced at the margin mar gin of con contac tactt of the reagents reagents.. The test sho should uld be che checke cked d wit with h a sample of fatty acids plus fatty matter to which a small amount of rosin has been added. NOTE 10—Cooperative studies have shown that the McNicoll method gives results approximatel approximately y 1 % highe higherr than the amoun amountt of rosin prese present. nt. Consequently, the committee recommends deducting 1 % from the percentage of rosin found in the fatty acids plus fatty matter.
47.2 If true fatty acid soap is desired, desired, subtract the rosin soap soap from the total anhydrous soap. SYNTHETIC DETERGENT (BY DIFFERENCE) 48. Calc Calculat ulation ion 48.1 Calcula Calculate te the percentage of anhydrous, anhydrous, salt-free, synthetic detergent as follows: D 5 K 2 ~ A 1 F 1 C !
A
Cox and Evers, “Report of British Standards Committee,” Analyst , Vol 62, No. 741, pp 865–870 (1937); also McNicoll, D., “The Estimation of Rosin Acids in Fatty Mixtures,” Journal, Soc. Chemical Industry, Vol 40, p. 124 T (1921).
(10)
where: D = weigh weightt per percen centt of anh anhydr ydrous ous,, sal salt-f t-free ree syn synthe thetic tic detergent, = weigh weightt percent percent of alcoho alcohol-solu l-soluble ble matter (Sectio (Section n 14 14), ), K
(9)
R 1 5 R 2 1.0
8
R 2 5 ~ R 1 3 B ! /100
s
44. Appar Apparatus atus
R 5 @ ~ V 1 2 V 2 ! N 3 0.346/ W W 1 # 3 100
B 5 E / W W 2 3 100
F C
= weig weight ht pe perc rcen entt of an anhy hydr drou ous, s, sal saltt-fr free, ee, so soda da so soap ap (Section 12 12)), = weigh weightt percent percent of free fatty matter (Sectio (Section n 40 40)), and = we weig ight ht percen percentt of chlori chloride dess (a (ass Na NaCl) Cl) in alc alcoh ohol ol-soluble matter (Section 43 43)).
48.2 In many cases, actual identificatio identification n and a more accurate determination of the percentage of synthetic detergent than that provided by 48.1 will be required. A complete listing of
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D820 − 93 (2016) analytical methods for the isolation of anionic, cationic, and nonionic surfactants is beyond the scope of this standard; see Test Metho Methods ds D1768 and D3049, D3049, Test Test Metho Method d D2358, D2358, and Classification D2357 for for this infor information mation.. Other applicable standards may be found by consulting the annual index. NEUTRAL INORGANIC SALTS
where: = weight percen percentt of neutra neutral, l, inorga inorganic nic salts, S weig ight ht perc percen entt of ch chlo lori ride dess (a (ass Na NaCl) Cl) in alc alcoh ohol ol-C = we soluble matter (Section 43 43), ), M = weight percen percentt of moistu moisture re and other matter volatil volatilee at 105°C (Section 6 (Section 6), ), percentt of alcoho alcohol-solu l-soluble ble matter matter (Section (Section 14 14), ), K = weight percen
49. Calc Calculati ulation on
I
49.1 Calculat Calculatee the percen percentage tage of neutral inorganic inorganic salts as follows:
S
S 5 ~ 1001 C ! 2 ~ M 1 K 1 I 1 S ! a
(11)
a
= weight weight percen percentt of matter matter insolu insoluble ble in water water (Secti (Section on 15), 15 ), and = total alkalinit alkalinity y of matter insolu insoluble ble in alcoho alcoholl (alkaline (alkaline salts) (Secti (Section on 17 17). ).
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