REMOVAL OF IRON INTERFERENCE IN THE DETERMINATION OF SELENIUM IN GEOLOGICAL SAMPLES BY CONTINUOUS-FLOW HYDRIDE GENERATION ICP-AES

To remove the chemical iron interference in the determination of selen ium in rocks, soils and stream sediments by Continuous Flow Hydride Ge neration Inductively Coupled Plasma Atomic Emission Spectrometry (CF-H G-ICP-AES), a Liquid-liquid extraction using ammonium pyrrolidine-1-yl -dithioformate (APDC) as a masking agent and chloroform as an extracti ng agent at pH 0.5-2.0 is proposed. Quantitative extraction of copper interfering seriously with the selenium determination by HG-ICP-AES is also achieved. Selenium could be accurately determined for selenium: iron ratios of 1 : 10(6), with a detection limit of 0.15 ng ml(-1). Ap plication of the method to Geochemical Standard Reference Samples demo nstrated that results were statistically in good accordance with certi fied values.