Reliable LC-MS/MS method integrated with a linear retention index approach for multiresidue pesticide analysis in hemp seed oil.

The increasing global demand for hemp seed oil (HSO) necessitates robust analytical methods to monitor pesticide residues and ensure compliance with increasingly stringent international regulations. This study presents a rapid and efficient multiresidue method for the determination of 148 pesticides in HSO using liquid chromatography-tandem mass spectrometry (LC-MS/MS), coupled with a linear retention index (LRI) approach to enhance compound identification confidence. The method features a streamlined extraction protocol with reduced solvent consumption (5 mL ACN per sample) and achieves chromatographic separation within 12 min. Method validation demonstrated excellent sensitivity (LOQs, 0.03-22.29 ng g⁻1), accuracy (71-129%), and precision (RSD ≤ 19.9%). Integration of the LRI system enabled unambiguous differentiation of isomeric compounds. Application of the method to 12 commercial HSO samples revealed the presence of 21 pesticides, with malathion and proquinazid exceeding Canadian maximum residue limits (MRLs) in two samples. This robust and eco-efficient method provides a robust solution for pesticide monitoring in HSO, aligning with EU, Canadian, and Californian regulatory frameworks while introducing LRI as a valuable tool for pesticide analysis in complex lipid matrices.