STANDARDLESS GRAPHITE-FURNACE ATOMIC-ABSORPTION SPECTROMETRY - DETERMINATION OF THALLIUM

Influences of atomization temperatures on the characteristic mass of t hallium in the graphite furnace with the V-shaped boat were studied. T he theoretical values of characteristic mass for thallium in the regio n of temperature(1800-2700 K) were calculated. The experimental result s show that the calculated atomization efficiency (beta(alpha)) of Tl in the pyrocoated graphite tube with the V-shaped boat and the Pd and the ammonium salt of EDTA as a matrix modifier is close to 100 % for a ll temperatures (1800-2500 K). The analytical method on the basis of t he calculated value of characteristic mass for the determination of th allium by furnace with the V-shaped boat using the pd and the ammonium salt of EDTA as a matrix modifier is described. It was found that the re were no interferences from 0.1 mol/dm3 HClO4, 40 mug/ml of Na(NaCl) , Ca(CaCl2), Si(Na2SiO3) and K(KNO3) in the presence of 10 mug/ml Pd a nd 2%(v/v) ammonium salt of EDTA. The proposed method applied to deter mination of thallium in the drainage sediment and geochemical referenc e samples and the results of sample analyses were a good agreement wit h the expected values.