Application of photochemical reactions of Se in natural waters by hydride generation atomic fluorescence spectrometry Original Research Article

A simple, sensitive and accurate method for selenium speciation in natural waters is proposed. The principle of this method is based on recently discovered photochemical reactions of Se(IV) and organic selenium in different aqueous solutions. The speciation of all selenium species was performed with hydride generation–atomic fluorescence spectrometry. Only one pre-reduction step is needed in this procedure, which can greatly reduce the risk of contamination, minimize the analytical work and improve the quality of selenium speciation. In this paper, a comparison is made between the proposed method and a previous method [A.G. Cutter, Anal. Chim. Acta 98 (1978) 59]. In this proposed protocol, Se(IV) was directly measured in 3.0 M HCl. Se(IV) + org-Se was measured directly after a UV irradiation (300 nm) for 2.5 h in a 1.0% (v/v) HNO3–2.0% (v/v) HCl matrix. Total selenium was obtained in another aliquot sample after a UV irradiation in the 3.0 M HCl. No pre-concentration, separation or more sophisticated instruments are required.