Validation of a method for the determination of tributyltin in seawater by stir bar sorptive extraction-liquid chromatography tandem mass spectrometry.

The main objective of this work is to develop an accurate, sensitive, simple and cost-effective method for the determination of tributyltin species (as cationic form) in seawater at ultra-trace levels. The method is based on the use of stir bar sorptive extraction (SBSE) followed by solvent desorption and liquid chromatography tandem mass spectrometry (SD-LC-MS/MS (QqQ)) analysis, operating in positive electrospray ionisation (ESI) and in the selected reaction monitoring (SRM) mode. Extraction and LC-MS/MS parameters were accurately optimised to achieve the highest recoveries and to enhance the analytical characteristics of the method.