Determination of Zinc Dialkyl(Diaryl)Dithiophosphate in Lubricating Oil

摘要

The overall objective of the project is the development of new and improved methods for determining composition of lubricating oils used in internal-combustion engines. This particular study is concerned with the development of analytical methods for identifying, separating, and determining the concentration of zinc dialkyl(diaryl) dithiophosphate additive present in fully formulated lubricating oils. Simple, rapid, qualitative tests for identification of the additive were developed. The additive was separated from the base hydrocarbon oil and isolated in a concentrated form by means of elution chromatography on silica gel-celite mixtures. The best results were obtained when the water content of the silica amounted to about 15-20 percent. The approximate concentration of the additive was determined by a combination of methods consisting of hydrolysis, elution and gas chromatography, as well as elemental analysis. (Author)