摘要 : Organotin (OTC), organolead (OLC) and organomercury (OMC) compounds are highly toxic and exhibit a potential negative effect on terrestrial ecosystems. Individual ionic OTC, OLC and OMC compounds were identified and their concentr... 展开 Organotin (OTC), organolead (OLC) and organomercury (OMC) compounds are highly toxic and exhibit a potential negative effect on terrestrial ecosystems. Individual ionic OTC, OLC and OMC compounds were identified and their concentrations determined in the gas phase, aerosol particles, and bulk precipitation at a rural (Waldstein) and an urban (Bayreuth city) site in NE-Bavaria. At both sites, butyltins, methyltins, octyltins, trimethyllead and monomethylmercury concentrations in the gas phase were < 100 pg m(-3) (determined as corresponding Sn, Pb and Hg concentrations, respectively) with the dominance of tri- and di-substituted OTC and octyltins. The same species were found in bulk precipitation with concentrations < 25 ng l(-1) (Sn, Pb, Hg) with the dominance of mono- substituted OTC. In aerosols, only butyltins, dimethyltin and monomethyltin (< 500 pg Sn m(-3)) were found and mono-substituted OTC predominated. No significant difference of concentrations of organometallic compounds in the atmosphere at the two sites was found. For OTC, the washout factors was in the order: mono- greater than or equal to di- > tri-substituted OTC, and the gas/particle partition coefficients were mono- > di- > tri-substituted OTC. The distribution spectrum of OTC in aerosols showed the strong linkage of OTC to the long-lived particles and high accumulation of OTC in the filter at the Waldstein site. The results indicate that long-range-transport of organometallic compounds in the atmosphere is an important source at our both sites. Aerosol particles may serve as a sink in the chemical cycles of OTC in the atmosphere, especially for monomethyltin and monobutyltin. (C) 2004 Elsevier Ltd. All rights reserved. 收起