title: Influence of speciation on the response from selenium to UV-photochemical vapor generation.
abstract: By exposure to appropriate UV intensities, rapid and quantitative oxidation/reduction of inorganic selenite, selenate and several organoselenium compounds representative of those of biochemical/metabolic interest, including selenomethionine, selenobetaine, L-selenocystine, selenomethylselenocysteine, γ-glutamyl-seleno-methylselenocysteine and selenocystamine, is achieved. In the presence of acetic acid, quantitative conversion to volatile SeH(2) and SeCO occurs using a flow-through system comprising a highly efficient 40 W UV lamp for oxidation in tandem with a lower power 8 W UV photocatalytic reactor utilizing a thin-film coating of titania. The volatile reduced species are detected by atomic absorption spectrometry using a heated quartz tube atomizer. Direct photochemical conversion of selenite, selenomethionine, L-selenocystine, γ-glutamyl-Se-methylselenocysteine and selenocystamine occurs in the presence of 5% acetic acid, following exposure to an 8 W UV field, to yield volatile detectable species, whereas selenobetaine and selenate are unresponsive unless the latter is first subjected to oxidation by exposure to a highly efficient 40 W UV lamp and the selenate reduced in the presence of titania.
authors.affiliation: National Research Council Canada, Measurement Science and Standards Portfolio, Ottawa, Canada. toshihiro.suzuki@aist.go.jp
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Suzuki
authors.forename: Ralph E
authors.initials: RE
authors.lastname: Sturgeon
authors.forename: Chengbin
authors.initials: C
authors.lastname: Zheng
authors.forename: Akiharu
authors.initials: A
authors.lastname: Hioki
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Nakazato
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Tao
mesh_terms: D010084:Oxidation-Reduction; D055668:Photochemical Processes; D012643:Selenium / Q000032:analysis / Q000737:chemistry* / Q000528:radiation effects*; D014466:Ultraviolet Rays; D014835:Volatilization
chemical_list: D012643:Selenium