CHELATION/ SOLVENT EXTRACTION BASED ESTIMATION OF LEAD AND CADIUM IN DRINKING WATER THROUGH ATOMIC ABSORPTIION METHOD

Abstract

An acid - medium ammoniur.l pyrrolidinpcarbodithioate (APDC) based chelation/solvent extraction preconcentration method is proposed for the estimati o n o f lead and cadr.lium in drinking waters . Optimum atomic absorption operatjng conditions in terms of fuel and air flm ... rates , burner height ann lamp current are established t o achieve enhanced absorption sensitivies as function of pH of th ~ med ium. An optimal pH range of 2.6 - 3 . 5, maintained with glacial acetic acid, gives above 80 percent recovery in a sing l e step eytraction. Enrichment factors are comp uted for six organic so lv e nts wi th a precision of ~ 1 .5% at a fairly high SiN ratio . The ~et h od is qLlantitativ ~, employs only a 15 ml aliquot of the water sa~ple to bE' analysed, and has the pot e ntial of <l["p lication to waters of varied nature with the lower detection limit at p[.lb l evel.