MICROBATCH VENTURI-TYPE SYSTEM FOR DETERMINATION OF SELENIUM(IV) BY HYDRIDE GENERATION ATOMIC-ABSORPTION SPECTROMETRY

A simple microbatch system for the determination of selenium(IV) by us e of hydride generation atomic absorption spectrometry was developed. The principle is based on the aspiration of the hydride formed in the reaction flask and its transport to the atomization cell, A Venturi-ty pe device and argon as carrier gas are used. The microbatch system has an analytical range up to 100 ng Se with low consumption of reagents. The characteristic mass obtained was 0.16 ng, with a relative standar d deviation of 1.3%, based on ten replicate measurements of aliquots c ontaining 50 ng of Se in aqueous solution. The detection limit was 0.8 0 ng at 90% confidence level. Selenium(Iv) was determined in two sampl es of drinking water spiked with an Se reference solution. The recover ies were 99 and 103% (mean of ten replicates).