Gas phase detection of tributyltin chloride arising from aqueous and solid matrices

Abstract

The vapour phase above water spiked with tributyltin chloride (TBTCl) and PACS-2 sediment certified reference material was sampled with a solid phase microextraction fiber. The collected volatile compounds were analysed by GC-MS using a HBr–methanol-treated capillary column. Two ion sources were used for this study and their performance characteristics compared. These were electron impact (EI) and negative chemical ionisation (NCI), which allowed both detection of trace amounts of analytes (NCI source) and their identification. This approach provides structural information on the sampled species; at this stage no quantitation was attempted. TBTCl can be detected in the vapour phase above saline water or PACS 2 sediment after one night of passive sampling without any stirring or heating of the sample. This work indicates the need to consider evaporation of TBT as the chloride as a mechanism of loss of this analyte from water or sediment. This may take place from natural settings and contributes to the global biogeochemical cycle of tin; hydride or methyl forms of trace metals are not the only compounds capable of volatilising into the atmosphere.