Optimization of a method for the determination of imidacloprid in cucumbers by liquid chromatographytandem mass spectrometry

Abstract

Objective: A method for the determination of imidacloprid pesticide residues in cucumber products by liquid chromatography tandem mass spectrometry was optimized and established. Method: According to the current national standard, the extraction solvent, extraction method, constant volume liquid and mobile phase of imidacloprid pesticide in cucumber samples were compared. After optimization, acetonitrile-water mixed solution (3:1) was used as extraction solvent, and the sample was pretreated by QuChERS method. The constant volume of 50% methanol solution was carried out, and the mobile phase 0.1% acetic acid (phase A) and acetonitrile (phase B) were injected into the sample for detection and analysis. The standard curve method in external standard method was used for quantitative analysis to evaluate the precision and accuracy of the detected concentration of agricultural residues. The optimum condition was that the detection concentration (recovery rate) was close to 100%. Results: The detected concentrations of imidacloprid were 21.862ng·ml-1~248.311ng·ml-1, and the recoveries were 88.74%~99.32%.Conclusion: By using optimized method, the imidacloprid residue in cucumber was analyzed by sampling, and the results showed that the peak condition was good, the detection concentration was high, and the recovery rate was good, it can provide a new improvement and supplement to the analysis and detection process of GB23200.121-2021, and widen the path for the analysis and detection of imidacloprid in vegetables.