Determination of 50 pesticide residues in dry chilli by gas chromatography-tandem mass spectrometry

A method for the determination of 50 pesticide residues such as dichlobenil, fluxapyroxad, fluopicolide, metrafenone, etc, in dry chilli was established using solid phase extraction (SPE) combined with gas chromatography-tandem mass spectrometry (GC-MS/MS). After being soaked in water, the samples were extracted with acetonitrile, salted out with sodium chloride, and then centrifuged. The supernatant was cleaned-up by SPE column of CARB/NH₂, then dissolved and diluted to 1.0 mL with ethyl acetate. The targeted compounds were detected by GC-MS/MS and then quantified by the matrix-matched external standard calibration method. The results showed that among the 50 pesticides, 46 analytes displayed good linearity in the range of 0.005-0.5 mg/L, with determination coefficient (R²) ≥ 0.99. The limits of quantitation (LOQ) ranged from 0.01 to 0.1 mg/kg. The average recoveries for the 46 pesticides at spiked levels of 0.01, 0.1, 1.0 mg/kg in dry chilli were in the range of 72%-120%, and the relative standard deviations (RSD) were between 0.7% and 17%. The method is simple, rapid, highly efficient, and the sensitivity, accuracy, and precision meet the daily routine testing requirements. It is suitable for the simultaneous detection of multiple pesticide residues in dry chilli samples.