Volatilization of Organotin Compounds from Estuarine and Coastal Environments

Abstract

The occurrence and speciation of volatile tin compounds (Sn) have been investigated in a contaminated area of the Arcachon Bay (SW France) and in the water column of the Scheldt (Belgium/Netherlands) and Gironde (SW France) estuaries. This paper describes the application of a multiisotope analytical method, using gas chromatography and inductively coupled plasma-mass spectrometry. Analytes were collected by cryogenic trapping of the gaseous species. This trapping has allowed us to probe volatile tin compounds by detecting both 118 Sn and 120 Sn isotopes. Volatile organic tin compounds have been determined in both sediment and water. They could result from both natural methylation and hydridization processes of inorganic tin (R n R′ 4-n Sn; R ) Me, R′ ) H, n ) 0-4) and from anthropogenic butyltin derivatives released from ship antifouling paintings which have accumulated in sediments (R n R′ 4-n Sn; R ) Bu, R′ ) H or Me, n ) 0-3). The most ubiquitous species were found to be the methylated forms of butyltin derivatives (Bu n SnMe 4-n , n ) 0-3). These results suggest that biological and/or chemical methylation mechanisms are likely to occur in sediments and to lead to remobilization of tin species into the water column and subsequently to the atmosphere. Finally, sediment-water and wateratmosphere fluxes have been calculated to assess the potential impact of these processes on the fate of organotin compounds in coastal environments.

The analysis of volatile trace compounds in landfill gases, compost heaps and forest air

“…However, the presence of methylbutyltin compounds could be anticipated as products of biological processes involving anthropogenically introduced butyltin compounds. Indeed, all the compounds Bu n SnMe 4Àn , n = 0±3, have been found in coastal sediments and water (but not in air) 19 and Bu 3 SnMe is produced in in vitro experiments that used natural sediments. 20 In order to confirm the presence of dibutyldimethyltin and tributylmethyltin in the landfill gas, the compounds were synthesized from methylmagnesium iodide and the appropriate butyltin chloride in diethyl ether.…”

“…20 In order to confirm the presence of dibutyldimethyltin and tributylmethyltin in the landfill gas, the compounds were synthesized from methylmagnesium iodide and the appropriate butyltin chloride in diethyl ether. 19 For identification, 1 ml of the reference tin solution was directly injected into the cooled trap capillary that also contained, in one case, the landfill sample. The trap capillary was connected to the peristaltic pump to pull in the injected reference sample.…”

Interim Results From a Study of the Impacts of Tin(ii) Based Mercury Treatment in a Small Stream Ecosystem: Tims Branch, Savannah River Site

“…Tin is subject to microbial methylation in both aerobic and anaerobic sediments and methyltin compounds have been detected in both fresh and salt water (Ridley et al 1977, Braman and Tompkins 1979, Gilmour et al 1985, Chen et al 2007, Jackson et al 1982, Craig and Rapsomanikis 1985, Amouroux et al 2000, Rapsomanikis and Weber 1985. While the fraction of tin that was observed to be methylated by natural processes in many environments was relatively low and the conditions that maximize methylation (e.g., high salinity) are not present in typical freshwater streams, the potential exists for tin methylation in freshwater stream and riparian systems receiving long term discharges from outfalls being treated using tin(II) chloride and air stripping.…”

Assessing Potential Impacts of Stannous Chloride Based Mercury Treatment on a Receiving Stream Using Real-World Data From Tims Branch, Savannah River Site

“…Issue 1: Tin is subject to microbial methylation in both aerobic and anaerobic sediments and methyltin compounds have been detected in both fresh and salt water (Ridley et al 1977, Braman and Tompkins 1979, Gilmour et al 1985, Chen et al 2007, Jackson et al 1982, Craig and Rapsomanikis 1985, Amouroux et al 2000, Rapsomanikis and Weber 1985. While the fraction of tin that was observed to be methylated by natural processes in many environments was relatively low and the conditions that maximize methylation (e.g., high salinity) are not present in typical freshwater streams, the potential exists for tin methylation in freshwater stream and riparian systems receiving long term discharges from outfalls being treated using stannous chloride and air stripping.…”