GF AAS determination of cadmium, lead and copper in environmental materials and food products after separation on Dithizone sorbent

A group separation method by solid phase extraction on the dithizone sorbent for cadmium, lead and copper and their determination by GF AAS were developed. The method may be applied for a large variety of environmental materials and food products. The procedures of preliminary preparation and mineralization of various types of analytical samples were also developed. Accuracy of the method was estimated by determination of the analyzed elements in the three various certified materials. In all cases the obtained results were inside the scheduled confidence intervals. The detection limits (LOD) calculated for the samples dried to a constant weight at 70 oC were estimated for cadmium, lead and copper as 2 ng g-1, 20 ng g-1, and 2 ng g-1,, respectively. Relative standard deviations (RSD %, n = 5) were estimated by multiple determinations of cadmium, lead and copper in commercially available various food products and in a few collected environmental samples. Most of the estimated RSD values oscillated in the range below 2%. The highest values RSD did not exceeded 3%. (authors)