PEAK SPLITTING OBSERVED DURING CAPILLARY ELECTROPHORESIS OF ALPHA-NAPHTHOL AND BETA-NAPHTHOL IN BORATE BUFFER

beta-Naphthol is an undesirable by-product in the synthesis of alpha-n aphthol for various uses in the pharmaceutical and dyestuff industries . We have developed a new procedure for the determination of traces of beta-naphthol in the presence of a large excess of alpha-naphthol. Th e new method utilizes direct UV detection at 230 nm in a 44.5 cmX75 mu m I.D. fused-silica capillary. The separation is carried out at 15 kV in a 50 mM berate electrolyte and pH of 9.3. During the research for optimum conditions, we were able to observe an occasional splitting of the peak belonging to beta-naphthol. Under certain conditions, we cou ld see up to three peaks for that compound. The realization that the p eak splitting could be observed reproducibly under alkaline conditions and with increased berate concentration (higher than 50 mM) helped us to elucidate the mechanism behind the peak splitting phenomena. The a rtifact was caused mainly by complexation reactions between beta-napht hol and berate polymers.