DETERMINATION OF COPPER, CHROMIUM, MANGANESE AND ZINC BY GRAPHITE-FURNACE ATOMIC-ABSORPTION SPECTROMETRY AFTER SEPARATION ON POLYACRYLAMIDEMODIFIED WITH NITRILO TRIACETIC ACID

A new chelating collector, polyacrylamide modified with nitrilo triace tic acid (NTA) was developed for the separation and preconcentration o f copper, chromium, manganese, and zinc prior to their determination b y Graphite Furnace Atomic Absorption Spectrometry (GFAAS). The retenti on and recovery of the analyte elements were investigated by applying batch and column techniques. Cu(II), Cr(III), Mn(II) and Zn(II) were q uantitatively retained by the collector at pH 5.5 or above. The chelat ing kinetics are so fast that in the batch procedure a quantitative se paration of the analyte elements can be achieved in a few seconds. Sin ce a very short contact time is enough to retain the analyte elements in column technique, a separation step can be completed quickly by app lying fast flow rates in small columns. The elements collected were co mpletely recovered with 2 mol/l of HCl. In the presence of sodium chlo ride up to 0.5% the analyte elements were quantitatively separated and recovered. Low blank values of the collector is another important adv antage.