Determination of tributyltin by automated in-tube solid-phase microextraction coupled with HPLC-ES-MS

A simple and sensitive method has been developed for the determination of tributyltin (TBT) in aqueous samples and environmental samples. Automated in-tube solid-phase microextraction (SPME) and high-performance liquid chromatography (HPLC) were coupled to a quadrupole mass spectrometer (MS) using electrospray (ES) as an ionization source. To achieve optimum performance, the conditions for both in-tube SPME and ES-MS detection were optimized for the analysis of TBT. A commercially available capillary, Supel-Q PLOT, showed the best extraction efficiency for TBT and, therefore, it was selected for in-tube SPME. The in-tube SPME-HPLC-ES-MS method provided a linear relationship between the analyte concentration and signal intensity in the range of 0.5-200 ng mL(-1) TBT, with a detection limit of 0.05 ng mL(-1). The method performance was evaluated by determining the content of TBT in a sediment reference material (PACS-2).