Simultaneous determination of trace amounts of chromium, cobalt and lead in waste water and plant materials by extraction - Atomic absorption spectrometry

A simple and rapid procedure has been developed for the determination of Cr, Co and Pb in waste water and plant materials by flame atomic absorption spectrometry (FAAS). In this method the metals are complexed with potassium propyl xanthate and extracted into methyl isobutyl ketone (MIBK) and analysed. Optimum conditions for quantitative determination of metals viz chromium, cobalt and lead are established by studying various parameters like the percentage of recovery in different solvents like butyl acetate, diisobutyl ketone, methyl isobutyl ketone and ethyl acetate, effect of reagent concentration and effect of pH. The data showed that the method could be employed for the determination of aforesaid metals in waste water and plant materials in the concentration range of 0.05-0.8 mu g/ml of cobalt and 0.12-1.6 mu g/ml of chromium and lead. The reliability of the method was assured by analysing the Standard Reference Materials (SRM-1570 and 1571) and by inter-comparison of Cr, Co and Pb values using inductively coupled plasma atomic emission spectrometry (ICP-AES).