Simultaneous determination of pinoxaden, cloquintocet-mexyl, clodinafop-propargyl ester and its major metabolite in barley products and soil using QuEChERS modified with multi-walled carbon nanotubes coupled with LC-MS/MS.

Abstract

Herein, a modified quick, easy, cheap, effective, rugged, and safe (QuEChERS) method with multi-walled carbon nanotube (MWCNT) as a dispersive solid-phase extraction was developed for simultaneous determination of pinoxaden (PXD), cloquintocet-mexyl (CLM), clodinafop-propargyl ester (CPE) and its major metabolite (clodinafop, CP) in barley grass powder, barley grain, and soil using liquid chromatography-tandem mass spectrometry (LC-MS/MS). We found that MWCNT as an absorbent could improve the recoveries of the tested analytes, particularly CP, in complex matrices. Under the optimum conditions, the established MWCNT-modified QuEChERS coupled with LC-MS/MS method exhibited excellent linearity (R2 ) of ≥0.9912, low limits of detection (LODs) and quantification (LOQs) of 0.02-0.07 and 0.29-1.26 μg kg-1 , and acceptable recoveries of 80-130% with intra- and inter-day relative standard deviations (RSDs) < 10.5%. No strong matrix effect (ME) has been observed on the respective samples. The method was successfully applied to monitor the tested analytes in the representative field incurred samples. Conclusively, the proposed method is sensitive and reliable and could be used to monitor the residues of PDX, CLM, CPE, and CP in complicated agro-products and soil matrices.