Direct determination of lead in used engine oils by atomic-absorption spectrophotometry

Abstract

An improved method has been developed for measuring lead in used lubricating oils. The procedure utilises a mixture of acid and a liquid anion exchanger (Aliquat 336) to dissolve the lead particles in 4-methylpentan-2-one and measurement is made by atomic-absorption spectrophotometry. The method is quantitative in the range 0.1–2.5%m/m and is independent of effects caused by variations in particle size, lead species or oil additives. The method is rapid and has good repeatability.