Comprehensive multiresidue determination of pesticides and plant growth regulators in grapevine leaves using liquid- and gas chromatography with tandem mass spectrometry.

Grape leaf, which is known for its nutritional and medicinal properties, is finding increased applications for cuisine and remedial purposes. This article reports a comprehensive analytical method for the identification and quantification of a broad range of pesticides and plant growth regulators (PGRs) in the grape leaf matrix. The sample preparation method for pesticides involved an optimized QuEChERS-based extraction protocol, with subsequent clean-up by the dispersive solid phase extraction (dSPE) using a mixture of sorbents (25 mg PSA + 5 mg GCB + 150 mg MgSO). The PGRs were extracted with methanol. The performance of the method was investigated and validated for a mixture of 363 pesticides (148 in GC-MS/MS and 203 in LC-MS/MS) and 12 PGRs (LC-MS/MS) in compliance with the analytical quality control criteria of the SANTE/11813/2017 guidelines. The matrix effects were comparatively higher against grape berries. The findings indicated satisfactory recoveries at 10 ng/g and higher levels with precision RSDs less than 20%. This method has potential applications in commercial residue testing laboratories and also for the regulatory compliance check purposes for its lower LOQs compared to the corresponding EU-MRLs.