1987 Volume 3 Issue 4 Pages 313-317
A new coprecipitation method for the fluorometry of selenium(IV) and selenium(VI) in groundwaters has been developed. Selenium(IV & I) were coprecipitated with zirconium(IV) hydroxide from 1l of roundwater at pH 8. Without aging, the precipitate was centrifuged nd then dissolved in hydrochloric acid. Selenium(IV) was determined y the usual fluorometry with 2, 3-diaminonaphthalene (DAN). From other portion of the same groundwater, selenium(IV) and selenium(VI) ere determined by the DAN fluorometry after reducing all the selenium o selenium(IV) by 6M hydrochloric acid treatment. The oncentration of selenium(VI) was obtained by subtracting that of elenium(IV) from the total for selenium. The established method is apid and convenient (taking about 2h for 10 sample treatments) ecause the precipitate is easily separable without aging. The method is able to detect nanogram amounts of selenium, for use with high urity zirconium reagents (containing 0.003ng Se in 1mg of Zr) and with two sub-closed glass vessels to avoid any contamination.