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 ab sorption spectrometry (FAAS). In this method the metals are complexed with potassium propyl xanthate and extracted into methyl isobutyl keto ne (MIBK) and analysed. Optimum conditions for quantitative determinat ion of metals viz chromium, cobalt and lead are established by studyin g various parameters like the percentage of recovery in different solv ents 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 concentrat ion range of 0.05-0.8 mu g/ml of cobalt and 0.12-1.6 mu g/ml of chromi um and lead. The reliability of the method was assured by analysing th e Standard Reference Materials (SRM-1570 and 1571) and by inter-compar ison of Cr, Co and Pb values using inductively coupled plasma atomic e mission spectrometry (ICP-AES).