Volatilization of tin as stannane in anoxic environments

Abstract

Recent reports of volatilization of metals from the aquatic environment demonstrate a previously unsuspected loss from the aquatic metal budget. Volatilization can occur by various mechanisms. Arsenic volatilizes from the aquatic environment as trimethyl- and dimethylarsine formed by biomethylation¹; plants and soils form volatile selenium compounds²; volatilization of mercury from the oceans might rival that of anthropogenic origin³; maritime air can contain a significantly higher fraction of alkyl-lead compounds to total lead than continental or urban air⁴. Finally, increasing evidence suggests the potential importance of tin volatilization through formation of tetramethyltin by chemical or biological methylation in the environment^5–7. We recently described possible formation of tetramethyltin by the macroalgae Enteromorpha sp. under oxic conditions⁶. Here we examine the contribution of decaying algal material to environmental cycling of tin by describing formation of volatile stannane (SnH₄) in anoxic environments.