Inductively coupled plasma atomic emission spectrometric determination of cadmium in biological and environmental 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 decomposition of alkylcadmium species. By using ethylmagnesium bromide as alkylating agent, a detection limit of 11 pg of cadmium was obtained. The precision (R.S.D., n = 6) was 3.4% for 100 pg of cadmium. Compared to the conventional metal furnace electrothermal vaporization method, an obvious improvement in tolerance limit was obtained for all of the foreign ions examined. The contents of cadmium in some biological and environmental reference materials was determined by the proposed method and the results were in good agreement with the certified values.