FAAS Determination of Barium and Zinc in Lube Additives with Emulsion Sample Introduction

Emulsification technique was applied to the pretreatment of lube additives.The lube additive sample was dissolved in ethyl acetate and emulsified by addition of Triton X-100.The emulsified sample solution was used directly for the FAAS determination of barium and zinc.Conditions for sample preparation and FAAS determination,including the amount of emulsifying agent used,interferences due to background absorption and co-existing substances,were studied and optimized.For matching the viscosity of the blank solution and testing solutions of working standards with the sample solution,appropriate amounts of agar solution were added.Values of RSD′s (n=6) and recovery found in the analysis of substantial samples were in the ranges of 2.0%-3.5% and 95.4%-103.0% respectively.