Simultaneous determination of cationic and anionic pharmaceuticals using an online SPE LC and a high-speed polarity switching ESI MS/MS

摘要

Newly developed high-speed polarity switching electrospray ionization (ESI) technology can acquire positive and negative ion monitoring simultaneously. We developed a high throughput analytical method using this technology combined with online solid phase extraction (SPE) column switching system for pharmaceuticals in wastewater effluents. Twenty eight pharmaceuticals including 20 cationic and 8 anionic compounds were analysed for in a 17-min LC run. Calibration curves in deionised water showed adequate linearity (correlation coefficients greater than 0.99) ranging from 5-1,000 pg on column. Recoveries from fortified effluent samples were 50%-138%. The developed method was further modified to minimise carryover, resulting in 10 fold reduction in carryover. The improved method also considerably saves the use of organic solvent per each sample analysis. This method can be extended to other emerging contaminants, including personal care products (PCPs) in aqueous samples.