Determination of Sulfur,Barium,and Silicon in Sebacate-Base Semi-Fluid Lubricants.

摘要

Methods are proposed for the determination of sulfur,barium,and silicon in sebacate-base semi-fluid lubricants. Sulfur is determined spec and gravimetrically. In the spectrophotometric method,the sample is treated with nitric,hydrochloric,and perchloric acids,magnesium chloride is added,and the solution is evaporated to dryness. The sulfate is then reduced to hydrogen sulfide by treatment with a mixture of hydriodic,hypophosphorous,and hydrochloric acids and the hydrogen sulfide is distilled into ammonium hydroxide. Lead citrate is added and the brownish-yellow color due to the lead sulfide sol is measured. An improved apparatus for the distillation is described. Ten samples of lubricants were analyzed and ignited in the usual manner. (Modified author abstract)