Abstract

In this paper we studied a simultaneous extraction process of As, Cd, Cr and Pb in waters by solid phase extraction technique followedby graphite furnace atomic absorption spectrometry. Accordingly, As(V) was reduced to As(III) in 0.5 % sodium thiosulfate prior to form Me-PDC complex with ammonium pyrrolidinedithiocarbamate (APDC). The complexation reactions were optimized at pH 4.0 for As(III), Cd, Pb and at pH 4.7 for Cr(III), Cr(VI). The non-polar MePDC complexes were retained on SPEC18 cartridge. This method may help to eliminate matrix interferences as well as topreconcentrate the analytes at the factor of up to 20 times. Parameters influence upon the extraction procedure and analysis were also investigated. Detection limits of method was 0.328,0.011, 0.080 and 0.109 µg/L for As, Cd, Cr and Pb, respectively. The method has been successfully applied to the determination of these metal ions in brackish water and sea water collected at Tien Giang province.