Optimization of a liquid-liquid extraction procedure of butyltin compounds and total tin in marine water samples using flame atomic absorption spectrometry

Two liquid-liquid extraction procedures have been optimized for analysis of sea water samples. Tributyltin (TBT), dibutyltin (DBT), and monobutyltin (MBT) compounds were extracted with tropolone in chloroform from samples acidified to 1 M with HCl. The extracts were evaporated to dryness and redissolved in methanol, prior to separation of the alkytin compounds by liquid chromatography. Total tin was extracted from samples at pH 2 using oxine in isobutylmethylketone (IBMK). The optimized extraction procedure for alkyltin compounds was used as a pretreatment of the samples when the speciation of tin was being performed. The IBMK solutions obtained from the extraction of total tin were directly subjected to electrothermal atomic absorption spectrometry, using zirconium-coated graphite tubes with L'vov platforms. (C) 1996 Academic Press, Inc.