SENSITIVE INDUCTIVELY-COUPLED PLASMA-ATOMIC EMISSION SPECTROMETRIC DETERMINATION OF CADMIUM BY CONTINUOUS ALKYLATION WITH SODIUM TETRAETHYLBORATE

Continuous flow generation of volatile Cd species using NaBEt4 as a me ans of gaseous sample introduction into an inductively coupled plasma atomic emission spectrometry (ICP-AES) instrument has been investigate d in detail. The assumed generation of CdEt2 is discussed and critical ly evaluated in terms of the sensitivity, selectivity and accuracy of the corresponding ICP-AES determination of low levels of Cd. The propo sed method for the determination of Cd by ICP-AES using NaBEt, provide d detection limits of 0.4 ng ml-1, which are ten times better than tho se of conventional nebulization ICP-AES. A precision of +/- 1.4% at th e 50 ng ml-1 level of Cd was observed. Interference studies have been carried out, which demonstrated high selectivity of the proposed metho d. This method has been applied to the determination of low levels of Cd by ICP-AES in samples of sea-water and tea infusions. Satisfactory validation of the results obtained has been provided by electrothermal atomic absorption spectrometric analysis of the same samples.