Liquid-phase microextraction of tributyltin and triphenyltin coupled with gas chromatography–tandem mass spectrometry: Comparison between 4-fluorophenyl and ethyl derivatizations

This paper describes the liquid-phase microextraction (LPME) of tributyltin (TBT) and triphenyltin coupled with gas chromatography–tandem mass spectrometry. The 4-fluorophenylation and ethylation reactions were used for the derivatization of the organotins. For the two derivatizations, the LPME parameters such as organic solvent, stirring rate, temperature, extraction time and the other additional conditions were examined. Using pure water, the calibration curves, method detection limits (MDLs) and reproducibilities (RSDs) of the two derivatizations were compared under the respective optimized procedures. The 4-fluorophenyl derivatization, which showed a lower MDL (0.36 ng/l) and better reproducibility (RSD = 11% at 10 ng/l) for TBT, was applied to the analysis of seawater. The TBT was detected in the range from 1.1 to 2.0 ng/l in the seawater samples collected in Osaka Bay.