ASTM D4047 Test Method for Phosphorus in Lubricating Oils and Additives
ASTM D4047 Standard Test Method for Phosphorus in Lubricating Oils and Additives by Quinoline Phosphomolybdate Method
5. Apparatus
5.1 Silica Crucibles, 40-mm internal diameter at the top and 40 mm in height. The internal surface should be smooth and free from pitting.
5.2 Muffle Furnace, capable of maintaining a temperature of approximately 700°C, and fitted with ports to allow air circulation.
5.3 Beakers, 25-mL capacity.
6. Reagents and Materials
6.1 Purity of Reagents - 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 Reagents of the American Chemical Society, where such specifications are available. Other grades may be used, provided it is first ascertained that the reagent is of sufficiently high purity to permit its use without lessening the accuracy of the determination.
6.2 Purity of Water - Unless otherwise indicated, references to water shall be understood to mean reagent water as defined by Type II or Type III of Specification D1193.
6.3 Hydrochloric Acid, approximately 1 N reagent solution.
6.4 Hydrochloric Acid (36 mass %) - Concentrated hydrochloric acid (HCl).
6.5 Hydrochloride Acid, (0.1 N) - Hydrochloric acid (HCl) accurately standardized.
6.6 Mixed Indicator - Mix 2 volumes of phenolphthalein solution with 3 volumes of thymol blue solution.
6.7 Phenolphthalein Solution, (1 g/L in 95 % volume ethanol).
6.8 Potassium Bromate (KBrO3), solid.
6.9 Quinoline (Warning - Quinoline has a high toxic acute systemic rating.) - Redistilled synthetic or, if this is unobtainable, quinoline freshly distilled from the technical product. Collect the colorless distillate in the boiling range from 232 to 238°C. Store the quinoline in an amber bottle in the dark.
6.10 Quinoline Hydrochloride Solution - Dissolve 20 mL of quinoline in 800 mL of hot water acidified with 25 mL of concentrated HCl; add a little paper pulp, cool, filter, and make up to 1 L with water. This solution is stable for about 1 month.
6.11 Sodium Hydroxide Solution (0.1 M) - Sodium hydroxide (NaOH) accurately standardized.
6.12 Sodium Molybdate Solution - Dissolve 10 g of sodium hydroxide (NaOH) and 18 g of ammonia-free molybdenum trioxide in 200 mL of water and filter the solution.
NOTE 2 - To avoid high blanks caused by silicate interference with alkaline reagents, including sodium molybdate solution, store in polythene containers.
6.13 Thymol Blue Solution (1 g/L) in 95 % volume ethanol.
6.14 Zinc Oxide (ZnO), finely divided.
