Recent studies of residual tributyltin in coastal British Columbia sediments

Autor: Y. K. Chau, Shannon Douglas, R. James Maguire, J. A. Jeffrey Thompson
Rok vydání: 1998
Předmět:
Zdroj: Applied Organometallic Chemistry. 12:643-650
ISSN: 1099-0739
0268-2605
DOI: 10.1002/(sici)1099-0739(199808/09)12:8/9<643::aid-aoc763>3.0.co;2-m
Popis: Butyltin concentrations in the sediments of two coastal areas of British Columbia, Canada, are reported. Two recent box cores from the deepest basin in the Strait of Georgia were sectioned and analyzed by GC–atomic emission spectrometry. No butyltin compounds were detected above 0.5 μgSn kg−1 (dry weight) in either core. These results are compared to those for a previous (1991) core from the same area. In that study, tributyltin (TBT) concentrations were in the range 1–2 μgSn kg−1 down the core and were higher than those of either of the degradation products, dibutyltin (DBT) and monobutyltin (MBT). Radioisotope dating (210Po–210Pb counting methods) was used to establish the rates of sedimentation of 0.25 and 2.6 cm y−1 at the two sites. Data suggest that a combination of rapid deposition of new, less-contaminated material and degradation of previously deposited butyltin compounds has resulted in the observed absence. Thirty-three surface sediments from the northern BC coastal harbor at Prince Rupert, collected in 1995, were analyzed for butyltin residues by GC–FPD. Concentrations of TBT, DBT and MBT were in the ranges from below the appropriate limit of detection (LOD) to 1262, to 109 and to 37 μgSn kg−1, respectively. TBT/DBT ratios ranged from 0.2 to 62 with most above unity, indicating that there is continuing fresh input of TBT. The sources are almost exclusively large ocean-going vessels that use the harbor for long-term anchorage. These findings are discussed with reference to the global TBT status. © 1998 John Wiley & Sons, Ltd.
Databáze: OpenAIRE
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