Hydride generation atomic absorption spectrometry from alkaline solutions: determination of selenium in copper and nickel materials

Abstract

Selenium is determined in copper and nickel materials without any interferences. Hydrochloric acid plus hydrogen peroxide are used to dissolve the samples. The solution is then made alkaline with sodium hydroxide in order to eliminate the interference from copper and nickel by precipitation of the corresponding hydroxides. Sodium tetrahydroborate is added to the alkaline solution in order to reduce selenium(IV) to the selenide ion, and the solution is then filtered. The volatile selenium hydride is generated by acidification of the alkaline solution in a continuous flow system. The method was used successfully for the determination of selenium in three standard reference materials (SRMs) from the National Institute of Standards and Technology: SRM 398 Unalloyed Copper V, SRM 671 Nickel Oxide 1 and SRM 875 Cupro-Nickel, 10 (CDA 706)(doped). The detection limit of the method was approximately 1 µg g^–1.