OPTIMIZED ARSENIC, SELENIUM AND MERCURY DETERMINATIONS IN AQUEOUS-SOLUTIONS BY ENERGY-DISPERSIVE X-RAY-FLUORESCENCE AFTER PRECONCENTRATION ONTO ZIRCONIUM-LOADED ACTIVATED-CHARCOAL

Adsorption onto zirconium-loaded activated charcoal (ZrC*) allows the efficient collection of arsenic, selenium and mercury from aqueous solutions in a thin layer, and at the same time removes or minimizes elemental interferences. When this preconcentration method is combined with energy dispersive x-ray fluorescence, the resulting analysis is accurate and precise. The method is simple and rapid and almost free from contamination because only a small amount of sodium hydroxide or nitric acid is required for pH adjustment, in addition to ZrC* adsorbent. Spectral interferences from other elements are negligible because the ZrC* adsorbent is highly selective. The procedure is also suitable for the determination of organometallic compounds of arsenic, selenium and mercury.