Comparative study of aqueous and non-aqueous capillary electrophoresis in the separation of halogenated phenolic and bisphenolic compounds in water samples

Capillary zone electrophoresis methods, based on either aqueous and non-aqueous solutions as running buffers and UV spectrophotometric detection, have been developed and optimized for the separation of several halogenated phenolic and bisphenolic compounds, suspected or proved to exhibit hormonal disrupting effects. Both aqueous capillary electrophoresis (CE) and non-aqueous capillary electrophoresis (NACE) methods were suitable for the analysis of compounds under study. The separation of the analytes from other 25 potentially interfering phenolic derivatives was achieved with NACE method. Large-volume sample stacking using the electroosmotic flow pump (LVSEP) was assayed as on-column preconcentration technique for sensitivity enhancement. LVSEP-CE and LVSEP-NACE improved peak heights by 5-26 and 16-330 folds, respectively. To evaluate their applicability, the capillary electrophoresis methods developed were applied to the analysis of water samples, using solid-phase extraction as sample pre-treatment process.