Capillary electrophoresis of triorganotin compounds with indirect fluorescence detection

A capillary electrophoresis-indirect fluorescence detection method for triorganotin compounds was developed. The five triorganotin cations, viz., trimethyltin, triethyltin, tripropyltin, tributyltin and triphenyltin, can be completely separated by capillary electrophoresis with a zwitterionic buffer of 70 mM N-2-hydroxyethyl-piperazine-N'-2-ethanesulfonic acid (HEPES) at pH 4.0. The running buffer also contains 1 mM 6-aminoquinoline (6-AQ) as the background fluorophore. Indirect fluorescence detection was performed using a non-laser-based fluorometer. The concentration limits of detection for the five triorganotin compounds were in the range 8-18 mu M (as tin), which correspond to a mass detection level of 80-180 fmol tin. The relative standard deviations were between 3.5 and 8.6%.