INDUCTIVELY-COUPLED PLASMA-ATOMIC EMISSION SPECTROMETRIC DETERMINATION OF CADMIUM IN BIOLOGICAL AND MATERIALS USING ELECTROTHERMAL VAPORIZATION AFTER IN-SITU ALKYLATION

Trace amounts of cadmium in biological and environmental samples were determined by inductively coupled plasma atomic emission spectrometry by using an in situ alkylation/vaporization method. The alkylation and vaporization were carried out successively to suppress the decomposit ion of alkylcadmium species. By using ethylmagnesium bromide as alkyla ting agent, a detection limit of 11 pg of cadmium was obtained. The pr ecision (R.S.D., n = 6) was 3.4% for 100 pg of cadmium. Compared to th e conventional metal furnace electrothermal vaporization method, an ob vious improvement in tolerance limit was obtained for all of the forei gn ions examined. The contents of cadmium in some biological and envir onmental reference materials was determined by the proposed method and the results were in good agreement with the certified values.