Interferences removal for cadmium determination in samples with complex matrices by hydride generation coupled with non-dispersive atomic fluorescence spectrometry

An intermittent on-line concentration and separation system coupled with HG-AFS was developed to eliminate serious interferences from Cu2+, Pb2+ and Zn2+ on the determination of cadmium. In the present method, the interferences from common coexisting ions, such as Cu2+, Pb2+, Zn2+, Fe3+ and Ni2+, were greatly reduced. Under the optimized conditions, a detection limit of 3 pg ml(-1) (3 sigma, n = 11) and a precision of 1.9% RSD for 1 ng ml(-1) of Cd were obtained. The method was successfully applied to the determination of cadmium in a series of Chinese Geological Reference Materials (SRMs) and GBW01621 ferronickel alloy using simple aqueous standard calibration technique. The results obtained were in good agreement with the certified values.