Novel eco-friendly method for pesticide residue detection in tap water: Menthol-based hydrophobic deep eutectic solvent extraction coupled with GC-MS/MS

From the paper

Abstract

A novel, rapid, sensitive, and green dispersive liquid-liquid microextraction method using menthol-based hydrophobic deep eutectic solvent (MHDES) drops coupled with gas chromatography-tandem mass spectrometry (MHDES-DLLME-GC-MS/MS) was developed for the extraction and detection of 57 pesticides (organochlorine pesticides (OCPs) and pyrethroids (PYRs)) from tap water. Among fifteen evaluated MHDESs, the menthol: octanoic acid (1:1) MHDES exhibited the highest extraction efficiency. Optimal conditions (20 µL DES, 1.0 % NaCl, 55-second vortex) were established using the Box-Behnken design. Method validation indicated negligible matrix effects for 51 of 57 analytes, with method detection limits (MDLs) and quantification limits (MQLs) ranging from 0.013 to 0.031 μg/L for OCPs and 0.03–0.06 μg/L for PYRs. Intraday and interday precision showed excellent relative standard deviations (RSDs) of 0.61–9.87 %. Absolute recoveries ranged from 87–108 %, achieving high enrichment factors (422–548). The method's greenness, assessed using AGREEPrep, yielded a score of 0.66, providing an effective alternative for pesticide analysis in tap water. The method was also successfully applied to other matrices, such as Cordyceps militaris extracts, oolong tea, and apple juice. This MHDES-DLLME-GC-MS/MS method provides an effective and sustainable alternative for pesticide analysis in tap water and other water-based samples, contributing to environmental protection.