Determination of butyltin species in natural waters using aqueous phase ethylation and off-line room temperature trapping

Monobutyltin (MBT), dibutyltin (DBT) and tributyltin (TBT) were determined in natural water samples by aqueous phase ethylation with sodium tetraethylborate (STEB), room temperature trapping of the resulting volatile derivatives on Tenax TA((R)), followed by gas chromatography-quartz furnace atomic absorption spectrometry (GC-QFAAS). Recoveries of butyltin spikes from natural water samples were 90-109% at concentrations of similar to100 ng Sn/l. The method precision at similar to 100 ng Sn/l was less than or equal to6% RSD for butyltins spiked into natural waters. The detection limits for 1 l water samples were < 1 ng Sn/l for all butyltin species. Sample throughput of the method is high (greater than three samples per hour) due to the two-stage nature of the procedure, which allows derivatisation/trapping and GC-QFAAS quantitation to be performed separately. Off-line trapping is also advantageous as it extends the life of the GC column and quartz furnace to at least 12 months due to minimisation of carry-over of co-purged material. (C) 2002 Elsevier Science B.V. All fights reserved.