An Application of Nitrogen Microwave-Induced Plasma Mass Spectrometry to Isotope Dilution Analysis of Selenium in Marine Organisms

Abstract

Nitrogen microwave-induced plasma mass spectrometry was studied for its applicability to the isotope dilution analysis of selenium in biological samples. Spectroscopic interference by calcium, which is present in high concentrations in biological samples, was investigated. No detectable background spectrum was observed for the major selenium isotopes of ⁷⁸Se and ⁸⁰Se. No detectable interferences by sodium, potassium, calcium and phosphorus on the isotope ratio ⁸⁰Se/⁷⁸Se were observed up to concentration of 200 mg/ml. The method was applied to the analysis of selenium in biological reference materials of marine organisms. The results showed good agreement between the certified and found values.