Preparation and application of polystyrene-divinylbenzene sorbent with weak cation-exchange character for the selective extraction of illicit drugs in environmental water

A B S T R A C T A novel mixed-mode weak cation-exchange sorbent (PS-DVB-WCX-II) was prepared by the modification of polystyrene-divinylbenzene with mercaptosuccinic acid for the selective extraction of illicit drugs in environmental water. The PS-DVB-WCX-II was synthesized through the Friedel-Crafts acylation reaction on the surface of polystyrene-divinylbenzene, followed by nucleophilic substitution reaction and thiolene click reaction. The sorbent can selectively absorb illicit drugs through the reverse-phase interactions provided by benzene ring on the polymer backbone and the ion-exchange interactions provided by functional group (-COOH). As compared with the extraction performance of three commercial SPE cartridges, it was found that the prepared sorbent had better adsorption performance with the recovery values between 84.1% and 106.0% for the selected 11 illicit drugs under the optimized SPE conditions. Illicit drugs in environmental water were extracted by the sorbent, prior to the detection of UHPLC-MS/MS. Two quantitative methods were established respectively for the detection of 11 illicit drugs in different matrices of river water and wastewater. Both methods had good determination coefficient (r 2 > 0.992) in the range of 0.5-50 ng/L, 2.5-250 ng/L, 5-500 ng/L, and low limits of detection (S/N = 3) of 0.17-1.67 ng/L. In the real wastewater samples, the concentration of morphine was 18.3-126.3 ng/L, and the methamphetamine was 12.7-27.4 ng/L. Meanwhile, PS-DVB-WCX-II was compared with Oasis MCX and Oasis HLB in the detection of real wastewater samples. The results revealed that PS-DVB-WCX-II and Oasis MCX had better performance in absorbing methamphetamine than Oasis HLB, and PS-DVB-WCX-II had better ability to remove the matrix. The results suggested that the prepared weak cation-exchange sorbent had the potential in the application of illicit drug detection in environmental water.(c) 2022 Elsevier B.V. All rights reserved.

Automated summary

A novel weak cation-exchange sorbent (PS-DVB-WCX-II) was successfully prepared for the selective extraction of illicit drugs in environmental water. The sorbent demonstrated better adsorption performance compared to commercial SPE cartridges and showed high detection sensitivity in real wastewater samples.