DETERMINATION OF ARSENIC (III/V) BY X-RAY-FLUORESCENCE SPECTROSCOPY IN WATERS

A procedure is described for the speciation of Arsenic (III) and (V) by the use of selective preconcentration and wavelength-dispersive X-ray spectrometry (WD XRS). It has been shown that the optimized procedure exhibited recoveries in natural waters higher than 95%. The general ease of use, the demostrated accuracy and precision with a limit of detection below 1 mug/100 ml, (0,01 mug/g), and the possibility of direct analysis of the precipitate, are factors for recommending this approach to analyse Arsenic contamination in waters.