Speciation of organotin compounds by capillary electrophoresis coupled with hydride generation atomic fluorescence spectrometry

Capillary electrophoresis (CE) coupled with hydride generation atomic fluorescence spectrometry (HG-AFS) was developed for the speciation analysis of organotin compounds. The four organotin cations of trimethyltin (TMT), monobutyltin (MBT), dibutyltin (DBT), and tributyltin (TBT) were completely separated by CE in a 50 cm x 75 mu m i.d. fused-silica capillary at 15 kV and using a mixture of 50 mmol l 21 H3BO3-50 mmol l(-1) Tris-5% v/v methanol (pH 7.10) as electrolyte. 0.008 mmol l(-1) cetyltrimethylammonium bromide (CTAB) added to the electrolyte suppressed the adsorption of the organotin cations on the inner wall of capillary. The generated hydride species were detected on-line with AFS. The precisions (RSD, n = 5) were in the range of 1.7-3.1% for migration time and 3.8-4.7% for peak area response for the four organotin species. The detection limits ranged from 1-10 mmol l(-1) (as Sn).