DETERMINATION OF CADMIUM IN BIOLOGICAL-MATERIALS BY TUNGSTEN COIL ATOMIC-ABSORPTION SPECTROMETRY

A simple, low cost tungsten coil furnace was evaluated for electrother mal atomic absorption spectrometry (ETAAS). The open atomizer was resi stively heated by using a power supply with a voltage feedback circuit . The analysis time using a manually injected sample volume of 10 mul was 41 s. Acceptable precision (relative standard deviation <3%, n = 1 2 at 1.0 ng ml-1 of cadmium) was obtained for cadmium values ranging f rom 0.5 to 6.0 ng ml-1. The characteristic mass for peak height absorb ance was 0.5 pg. Results compare well with certified values of differe nt biological materials digested with nitric acid. For certain referen ce materials better accuracy was obtained from data based on integrate d absorbance.