Preconcentration and Determination of Cadmium and Lead by Ion-Pair Solid Phase Extraction on Silica Gel Followed by Flame Atomic Absorption Spectrometry

Abstract

The ion-pair formation between the metal complex with 4-(4'-nitrophenylazo)-1-naphthol and cetyltrimethylammonium bromide and its sorption on silica gel form the basis for preconcentration of cadmium and lead, which are subsequently determined on-line by flame AAS. The method was applied to the quantitation of cadmium and lead in potable and surface waters, with limits of determination (10s) of 0.5 and 2 μg l-1, respectively.