Isotope Dilution Analysis of Selenite and Selenate in Natural Water Using Microwave-Induced Nitrogen Plasma Mass Spectrometry

• Published in: Analytical Sciences 2003, Vol.19(10), pp.1359-1363
• Main Authors: MINAMI, Hirotsugu, CAI, Wanhong, KUSUMOTO, Tatsuya, NISHIKAWA, Kaiji, ZHANG, Qiangbin, INOUE, Sadanobu, ATSUYA, Ikuo
• Format: Article
• Language: English
• Subjects: Analysis methods; Analytical chemistry; Applied sciences; Chemistry; Exact sciences and technology; Fresh Water - analysis; Isotopes; Mass Spectrometry - methods; Natural water pollution; Pollution; Selenic Acid; Selenium Compounds - analysis; Sodium Selenite - analysis; Spectrometric and optical methods; Water treatment and pollution
• ISSN: 0910-6340; 1348-2246
• DOI: 10.2116/analsci.19.1359

Isotope dilution analysis of the sub-μg l-1 levels of selenite and selenate in natural water samples by microwave-induced nitrogen plasma mass spectrometry (MIP-MS) was performed. An appropriate amount of a spike solution containing 78Se-selenite and 78Se-selenate was added to the natural water sample to be analyzed. Both analytes in the water were then concentrated simultaneously by passing the sample through a column that was filled with an anionic exchange resin. After the concentration process, all of the selenite and some of the selenate on the resin were eluted by 0.03 M nitric acid. The residual selenate was eluted by 0.13 M nitric acid. The eluted sample solutions were injected into MIP-MS, and isotope dilution analyses were carried out. Selenite and selenate concentrations as low as 0.01 μg l-1 in the natural water sample were successfully determined by the proposed method.