ASTM D126:19 pdf download

ASTM D126:2019 pdf download.Standard Test Methods for Analysis of Yellow, Orange, and Green Pigments Containing Lead Chromate and Chromium Oxide Green.
3.1.4 Lead chromate is determined by dissolving the sample in dilute HC1, filtering and titrating potentiometrically with FeSO4 solution after addition of HC1O4.
3.1.5 Total lead is determined by precipitation as lead sulfide solution with H,S04 and final precipitation as lead sulfate.
3.1.6 Sulfate is determined by dissolving the sample in acetic acid, neutralizing with sodium carbonate, plus addition of HCI to an aliquot followed by addition of BaCk to precipitate as barium sulfate.
3.1.7 Carbon dioxide is determined by evolution.
3.1.8 Molybdenum is determined by precipitation as the sulfide, solution in HNO3 and H,S04, addition of NH4OH and H2S04. The solution is reduced in a Jones reductor, collected under Fe,(S04)3 solution and titrated with KMnO4 solution.
3.1.9 Extenders are either:
3.1 .9.1 Calcium carbonate, calcium sulfate, magnesium carbonate or;
(a) The compounds in 3.1.9.1 are determined qualitatively by precipitation with ammonium solution.
(b) If chromium is present, it is reduced and the lead salts dissolved in dissolving solution. Hydroxides and hydrous oxides arc precipitated by addition of HC1 and NH4OH and filtered. CaC,04 is precipitated with calcium oxalate solution and filtered. ashed and weighed as CaO. Alternatively, the precipitate is dissolved in HSO4 and titrated with KMnO4. Magnesium is determined on the filtrate from calcium determination by precipitation as the phosphate with ammonium phosphate solution.
3.2 Chroiniuni Oxide Green:
3.2.1 Organic colors and lakes are determined qualitatively by boiling the sample in waler, then ethyl alcohol, and finally choloroform.
3.2.2 Moisture and other volatile matter are determined in accordance with Test Method A of Test Methods D280.
3.2.3 Matter soluble in water is determined by boiling in water and filtering.
3.2.4 Total chromium as chromium oxide is determined by dissolving the sample in dilute HCI, filtering and titrating potentiometrically with FeSO4 solution after addition of
HC104.
4. Significance and Use
4. 1 These test methods are for analysis designed as an aid in quality of yellow, orange, and green pigments containing lead chromate and chromium oxide green. Some sections may be applicable to analysis of these pigments when extracted from whole paints.
NoTE 2——A0.1 % solution of sodium dioctylsuccinosulfonate has beenfound satisfactory. (This material is sold under the trade name of AerosolOT.) Wetting agents containing mineral salts, sulfates, or sulfonates whichmay be hydrolyzed to sulfates，should be avoided; the use of alcohol isalso undesirable because of its tendency to reduce chromates.
NoTE 3—Warning: As the National Institute for Occupational Safetyand Health has stated that hexavalent chromium compounds are hazardousto health，care should be exercised in preparation of the sample. Thewearing of a respirator and rubber or synthetic gloves are recommended.If hexavalent chromium materials come in contact with the skin，washthoroughly with soap and water.