A novel slurry sampling analysis of lead in different water samples by electrothermal atomic absorption spectrometry after coprecipitated with cobalt/pyrrolidine dithiocarbamate complex

A preconcentration/separation technique based on the coprecipitation of lead with cobalt/pyrrolidine dithiocarbamate complex (Co(PDC)(2)) and subsequently its directly slurry sampling determination by electrothermal atomic absorption spectrometry (AAS) was described. For this purpose, at first, lead was coprecipitated with cobalt/pyrrolidine dithiocarbamate complex formed using ammonium pyrrolidine dithiocarbamate (APDC) as a chelating agent and cobalt as a carrier element. The supernatant was then separated and the slurry of the precipitate prepared in Triton X-100 was directly analyzed by electrothermal atomic absorption spectrometry with respect to lead concentration. The effects of experimental conditions on coprecipitation of lead with gathering precipitate as well homegeneity and stability of slurry were investigated. After the optimization of experimental paramters, a 100-fold enrichment of the analyte with quantitative recovery (>90%) and high precision (<10% R.S.D.) were obtained. Byusing the proposed technique, the lead concentrations in heavy matrices of Certified Sea-water and wastewater samples could be practically and rapidly determined in the range of 95% confidence level. The detection limit of the described method for lead using sample-matching blanks was 1.5 ng/L (3 sigma, N = 10) (C) 2008 Elsevier B.V. All rights reserved.