Determination of Inorganic Selenium Species in Marine Waters by Hydride Generation-AFS

A method based on hydride generation with cryogenic trapping and atomic fluorescence detection was developed that is capable of determining both inorganic Se species (SeIV and SeVI) while at sea. Evaluation of the system for optimal performance was made for each stage of the analysis and detection sequence, as well as for the SeVI reduction step. A detection limit of 0.4 ng L-1 Se in a 10mL sample was achieved using this method. Precision was better than 3.5% for 25, 100, and 1000 ng L-1 SeIV standard solutions. Accuracy was determined by recovery studies using natural samples and a certified reference seawater (NASS-5).