Simultaneous determination of pharmaceutical and personal care products in wastewater by capillary electrophoresis with head-column field-amplified sample stacking

Abstract

A sensitive and reliable method using capillary zone electrophoresis with UV-diode array detection (CZE-DAD) has been developed and validated for trace determination of nineteen pharmaceutical and personal care products (PPCPs) in wastewater. Due to the lack of sensitivity of UV-vis detection, a solid-phase extraction (SPE) method for off-line preconcentration and cleanup of water samples, in combination with an on-line preconcentration methodology named head-column field-amplified sample stacking (FASS), has been applied. Several parameters affecting separation and FASS efficiency were investigated in detail, including the buffer pH and concentration, organic modifier, sample matrix, water plug, and electrokinetic injection voltage and time. Under the optimal FASS-CZE conditions, high efficiency was achieved and nineteen PPCPs were baseline separated within 27 min. The accuracy of this assay was ensured by spiking of real samples with standard known concentrations and the intra-day and inter-day relative standard deviations (RSDs) were below 5.6 and 6.3%, respectively. The average recoveries for water samples with the studied PPCPs were greater than 64.7 ± 1.1%. The limits of detection (LODs) were estimated to range from 1.4 to 46.4 ng L⁻¹ for the studied compounds. This method was successfully applied for the simultaneous determination of PPCPs in wastewater samples from a sewage treatment plant.