Automated Headspace SPME-Retention Time Locked-Isotope Dilution GC/MS for the Analysis of Organotin Compounds in Water and Sediment Samples

An automated method for the simultaneous determination of six important organotin compounds namely monobutyltin (MBT), dibutyltin (DBT), tributyltin (TBT), monophenyltin (MPhT), diphenyltin (DPhT) and triphenyltin (TPhT) in water and sediment samples is described. The method is based on derivatization with sodium tetraethylborate followed by automated headspace-SPME combined with GC/MS under retention time locked (RTL) conditions. Deuterated organotin analogues are used as internal standards. Limits of quantification (LOQs) are from 1.3 to 15 ng.L-1 (ppt) for water samples and from 1.0 to 6.3 μg.kg-1 (ppb) for sediment samples.