ASTM D444-88(2020) pdf free download.Standard Test Methods for Chemical Analysis of Zinc Yellow Pigment (Zinc Chromate Yellow).
ASTM D444-88(2020) cover procedures for the chemical analysis of the pigment known commercially as “zinc yellow” or “zinc chromate yellow.”
ASTM D444-88(2020) has been developed to standardize the chemical analysis of zinc chromate yellow pigment and to provide alternate methods of analysis for chromium and zinc.
Weigh to 0.1 mg 3 g of the oven-dried material from the determination of moisture and other volatile matter (Note 2 and Note 3), and place in a porcelain boat. Introduce the boat with the charge into a refractory combustion tube in an electrically-heated combustion furnace of the type used for the determination of carbon in steel by direct combustion (Note 4). Place the boat at the center of the combustion tube maintained at a temperature of 1000°C for 4 h. Draw a current of pure dry air or dry nitrogen through the tube to sweep the evolved moisture into a previously weighed absorption tube containing anhydrous magnesium perchlorate (Mg(ClO4)2) or other efficient desiccant. The weight increase of the absorption tube represents the “combined water.”
Ferrous Ammonium Sulfate Solution—Dissolve 80 g of ferrous ammonium sulfate (FeSO4 · (NH4)2SO4 · 6H2O) in 50 mL of H2SO4 (sp gr 1.84) and enough water to make 1 L of solution. Mix thoroughly before use. This solution is approximately 0.2 N.
Pipet a 25-mL aliquot of the solution of the specimen (Section 9) into a 500-mL glass-stoppered Erlenmeyer iodimetric flask or other suitable glass-stoppered bottle containing 200 mL of H2SO4 (1+39). Add 20 mL of KI solution (150 g/L), stopper, and allow the solution to stand for approximately 5 min.
ASTM D444-88(2020) pdf download
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