title: Identification of mercury methylation product by tert-butyl compounds in aqueous solution under light irradiation.
abstract: The methylation of mercury (Hg) is of great concern as methylmercury (MeHg), the most toxic species, is produced. This study examined the possibilities of tert-butyl compounds (tert-butyl alcohol (TBA) and tert-butyl hydroperoxide (TBH)) and other alcohols serving as methyl donors for Hg photo-methylation under light irradiation. The yield of MeHg varied among the methyl donors, and it was also significantly influenced by salinity and pH. MeHg could be generated in the presence of TBH under visible light irradiation. The hydroxyl radical (OH) was found to promote MeHg production at low levels, but degrade MeHg in excess. The photo-production of MeHg was tentatively proposed via the complexation of Hg and methyl donors, the formation of an intermediate (O(Hg)C(CH3)3), and the intramolecular methyl transfer from methyl donors to Hg. This study implicates photoreactions between Hg and organic pollutants in understanding the fate and transformation of Hg in the aquatic environment.
authors.affiliation: Guangdong Provincial Key Laboratory of Marine Resources and Coastal Engineering, School of Marine Sciences, Sun Yat-Sen University, Guangzhou 510275, PR China; State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center of Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing 100085, PR China. Electronic address: chenbw5@mail.sysu.edu.cn.
authors.forename: Baowei
authors.initials: B
authors.lastname: Chen
authors.affiliation: MOE Key Laboratory of Aquatic Product Safety, Instrumental Analysis & Research Center/School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275, PR China.
authors.forename: Ping
authors.initials: P
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center of Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing 100085, PR China.
authors.forename: Bin
authors.initials: B
authors.lastname: He
authors.affiliation: State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center of Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing 100085, PR China.
authors.forename: Yongguang
authors.initials: Y
authors.lastname: Yin
authors.affiliation: State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Northwest A&F University, Yangling 712100, PR China.
authors.forename: Linchuan
authors.initials: L
authors.lastname: Fang
authors.affiliation: Guangdong Provincial Key Laboratory of Marine Resources and Coastal Engineering, School of Marine Sciences, Sun Yat-Sen University, Guangzhou 510275, PR China.
authors.forename: Xiaowei
authors.initials: X
authors.lastname: Wang
authors.affiliation: MOE Key Laboratory of Aquatic Product Safety, Instrumental Analysis & Research Center/School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275, PR China.
authors.forename: Hongtao
authors.initials: H
authors.lastname: Liu
authors.affiliation: Guangdong Provincial Key Laboratory of Marine Resources and Coastal Engineering, School of Marine Sciences, Sun Yat-Sen University, Guangzhou 510275, PR China.
authors.forename: Lihua
authors.initials: L
authors.lastname: Yang
authors.affiliation: MOE Key Laboratory of Aquatic Product Safety, Instrumental Analysis & Research Center/School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275, PR China.
authors.forename: Tiangang
authors.initials: T
authors.lastname: Luan
mesh_terms: D006863:Hydrogen-Ion Concentration; D017665:Hydroxyl Radical; D008027:Light; D008628:Mercury / Q000032:analysis / Q000737:chemistry* / Q000378:metabolism*; D008745:Methylation; D008767:Methylmercury Compounds / Q000032:analysis / Q000378:metabolism; D054712:Salinity; D012996:Solutions / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000737:chemistry*
chemical_list: D008767:Methylmercury Compounds; D012996:Solutions; D014874:Water Pollutants, Chemical; D017665:Hydroxyl Radical; D008628:Mercury
keywords: Aqueous solution; Methylation; Monomethylmercury; Tert-butyl compounds; Ultraviolet irradiation