Speciation of organotin in sediments by multicapillary gas chromatography with atomic emission detection after microwave-assisted leaching and solvent extraction-derivatization

Microwave-assisted leaching of organotin compounds from sediment samples followed by the simultaneous extraction-derivatization of the extracted species was revisited with the goal to compare the existing procedures, improve their recoveries and extend them to phenyltin compounds. The stability of butyl- and phenyltin compounds under microwave field, real recoveries of the whole analytical procedure, effect of the extraction solvent, and the necessity for an internal standard were evaluated using two candidate reference sediments. The combination of the optimized sample preparation procedure with multicapillary chromatography resulted in a rapid (2 min leaching + 5 min extraction-derivatization + 3 min chromatographic separation) and efficient analytical procedure for speciation analysis of organotin compounds in sediment samples. The detection limit achieved with a microwave-induced plasma atomic emission detector was 2 ng g–1.