Determination of copper, chromium, manganese and zinc by graphite furnace atomic absorption spectrometry after separation on polyacrylamide modified with nitrilo triacetic acid

Abstract

A new chelating collector, polyacrylamide modified with nitrilo triacetic acid (NTA) was developed for the separation and preconcentration of copper, chromium, manganese, and zinc prior to their determination by Graphite Furnace Atomic Absorption Spectrometry (GFAAS). The retention and recovery of the analyte elements were investigated by applying batch and column techniques. Cu(II), Cr(III), Mn(II) and Zn(II) were quantitatively retained by the collector at pH 5.5 or above. The chelating kinetics are so fast that in the batch procedure a quantitative separation of the analyte elements can be achieved in a few seconds. Since a very short contact time is enough to retain the analyte elements in column technique, a separation step can be completed quickly by applying fast flow rates in small columns. The elements collected were completely recovered with 2 mol/l of HCl. In the presence of sodium chloride up to 0.5% the analyte elements were quantitatively separated and recovered. Low blank values of the collector is another important advantage.