title: Determination of dissolved selenium(VI) in freshwater.
abstract: A procedure is proposed for the determination of selenate in freshwaters with a high content of dissolved organic material. After passage through an XAD-8 column, selenate is collected on a strong anion exchanger and subsequently eluted with hydrochloric acid. Following conversion into the tetravalent state, selenium is determined using atomic absorption spectrometry after hydride generation and preconcentration in a cold trap system. The two-column procedure effectively separates selenium(VI) from possible organic interferents and allows quantification at the low ng/l. level. Results from the investigation of waters from lakes and streams indicate that selenium(IV) and (VI) may constitute a very small part of total dissolved selenium.
authors.affiliation: Uppsala University, Department of Analytical Chemistry, P.O. Box 531, S-751 21 Uppsala, Sweden.
authors.forename: U
authors.initials: U
authors.lastname: Ornemark
authors.forename: A
authors.initials: A
authors.lastname: Olin