Simultaneous determination of tributyltin and triphenyltin cations by capillary isotachophoresis with potential-gradient detector for direct detection

A capillary isotachophoresis procedure was developed for the determination of tributyltin (TBuT) and triphenyltin (TPhT) cations; 10 mM potassium hydroxide containing 0.1% Triton X-100 and 50% acetone was used as the leading electrolyte. The pH of the potassium hydroxide solution was adjusted to 5.0 with glutamic acid. The terminating electrolyte was 10 mM betaine hydrochloride. TBuT and TPhT were completely separated and directly detected using a potential-gradient detector. The values of the relative standard deviation of the zone length for TBuT and TPhT were 1.5% and 1.9%, respectively, when a 200 mu l volume of the mixture of 10 mg l(-1) of these ions was injected. The limits of detection for TBuT and TPhT were 0.46 and 0.57 mg l(-1), respectively (based on three times the standard deviation obtained by analyzing a mixture of 1.0 mM TBuT and 1.0 mM TPhT). (C) 1999 Elsevier Science B.V. All rights reserved.