Sensitive and Selective Spectrophotometric Assay of Lead in Aqueous Solution

A sensitive and selective spectrophotometric method for the determination of lead (II) in aqueous solution using zincon reagent has been developed. The pinkish red coloured complex was formed at pH 9.5 which shows maximum absorption at 543 nm. Beer's law is obeyed in the range 0.04 1.2 ppm with a molar absorbtivity of 9.84 x 104 l.mol -1cm-1. The established stoichiometry is l:l ligand: metal. The method seems to be selective through the study of cationic and anionic interferences, easy, rapid, accurate, reproducible, and the complex is stable for 24 hours. The optimum conditions and the applications of the method have been studied for the assay of lead in different water samples.