Simultaneous enantiomeric analysis of five proton-pump inhibitors in soil and sediment using a modified QuEChERS method and chiral high performance liquid chromatography coupled with tandem mass spectrometry

Abstract

This study presents a simple, sensitive, rapid, cheap and reliable method for the simultaneous quantification of five proton pump inhibitors (omeprazole, rabeprazole, lansoprazole, pantoprazole, and ilaprazole) at enantiomeric levels in environmental soil and river sediment by chiral high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). The modified QuEChERS procedure, a very simple and efficient sample preparation method, was employed for the extraction and purification of the target analytes. To obtain satisfactory chromatographic performance and high extraction efficiency, several experimental variable parameters including the type and content of the organic modifier, the content of the additive, temperature and mobile phase flow rate, the type and volume of extraction solvent, and the type and content of clean-up sorbent were systematically optimized. Under the optimum condition, the simultaneous baseline separation of five chiral drugs was achieved on a Chiralpak IH column within 13 min. The method detection limits and quantification limits of the enantiomers were below 0.17 ng/g and 0.69 ng/g, respectively. Correlation coefficients (R2) ≥ 0.9905 were obtained for all enantiomers within the linearity range of 1–200 ng/g. The mean recoveries for all enantiomers ranged from 83.6% to 108.5% with intra-day RSD less than 11.6% and inter-day RSD less than 12.9%. Finally, the proposed method was successfully applied to authentic samples (green belt soil, agricultural soil, and river sediment) to analyze the enantiomeric composition of target chiral analytes, indicating its applicability and reliability for the enantioselective determination of proton pump inhibitors in environmental matrices. This research will help better elucidate the behavior of individual enantiomer and make an excellent risk assessment on the environment.