THE CAPABILITY OF ULTRAFILTRATION AND ETV-ICP-MS FOR SIZE FRACTIONATION STUDIES OF ARSENIC AND SELENIUM SPECIES IN-GROUND WATER SAMPLES WITH HIGH-CONCENTRATIONS OF IRON, MANGANESE AND SULFUR

A simple, but highly sensitive procedure for the determination of part icular and colloidally bound arsenic and selenium species in ground wa ter samples with high concentrations of iron, manganese and sulfur is presented. Samples were first filtered through a 0.45 mu m filter to s eparate the particulate matter from the dissolved. Aliquots of the fil tered sample were submitted to ultrafiltration through membrane filter s with pore diameters of 30 nm and 1 nm, respectively. Filtrates were analyzed by ETV-ICP-MS for their arsenic and selenium concentration.