title: Microwave digestion of fish tissue for selenium determination by differential pulse polarography.
abstract: In KIO(3)NH(3)NH(4)Cl medium, the selenium complex Se(O)SO(2-)(3), resulted from the reaction of selenite and sulphite in acid solution, gave a catalytic wave, which was applied to the determination of selenium in fish by differential pulse polarography. The sample was decomposed using the HNO(3)/H(2)SO(4)/H(2)O(2) digestion mixture in a closed PTFE digestion vessel with microwave heating. The detection limit was 0.06 mug/dm(3). The calibration curve was linear up to 8 mug/dm(3). Selenate present was reduced with hot hydrochloric acid to selenite. The recoveries of the selenite and selenate in two spiked samples investigated ranged from 91 to 104%. The NIES CRM No. 6 mussel was analyzed and the results obtained agreed well with the reference value (reference value: 1.5 mug/g; found: 1.43 +/- 0.05 mug/g). The results obtained by differential pulse polarography were in good agreement with those found by hydride generation atomic absorption spectrometry.
authors.affiliation: Department of Chemistry, National University of Singapore 10 Kent Ridge Crescent, Singapore 0511, Republic of Singapore.
authors.forename: W G
authors.initials: WG
authors.lastname: Lan
authors.forename: M K
authors.initials: MK
authors.lastname: Wong
authors.forename: Y M
authors.initials: YM
authors.lastname: Sin