DETERMINATION OF SELENIUM IN GEOCHEMICAL SAMPLES BY FLOW-INJECTION HYDRIDE GENERATION INDUCTIVELY-COUPLED PLASMA-ATOMIC EMISSION-SPECTROMETRY FOLLOWING ONLINE REMOVAL OF IRON INTERFERENCE BY ANION-EXCHANGE

Selenium was determined in geological samples with a high content of i ron by HG-ICP-AES in combination with flow injection (FI) on-line iron separation, Anion-exchange separation with hydrochloric acid was appl ied for the separation of selenium from iron, The iron-chloro complexe s were adsorbed on an anion-exchange (Dowex 1X-8) microcolumn (3.0 mm id x 50.0 mm bed length), while the analyte was introduced into the hy dride generation system, After the removal of the iron, a 700 mu l sam ple was injected into a water carrier stream, This was merged with hyd rochloric acid and sodium tetrahydroborate in order to generate seleni um hydride, The system was found to have a limit of detection of 0.3 n g ml(-1) and an RSD of 2% for a 20 ng ml(-1) selenium concentration, T he application of the method to geochemical standard reference samples (GSD-4, GSS-7, GSR-6, JB-2 and JGb-1) demonstrated that the results w ere statistically indistinguishable from the certified values.