Abstract:

Objective To establish a method for determining 23 pesticide residues in 21 vegetables using ultra-high performance liquid chromatography-mass spectrometry（UPLC-MS/MS），and study the matrix effects of pesticide residues under the conditions of solid-phase extraction and quick，easy，cheep，effective，rugged and safe（QuEChERS） pre-treatment methods in different vegetable matrices. Methods Under the detection conditions of UPLC-MS/MS，different types of vegetable matrix effect were detected. Results The detection limit of the method was 0.000 01-0.005 11 mg/kg. The average relative standard deviation（RSD） of low，medium，and high concentrations were 2.67%-16.94%，4.64%-15.88%，and 1.91%-13.24%，respectively. The spiked recovery rates at concentrations of 80，160，and 320 μg/kg were 65.51%-110.90%，64.93%-107.25% and 64.79%-94.97%，respectively. Most of the 23 pesticides showed weak inhibition in 21 different vegetables，with a small portion exhibiting medium to weak enhanced matrix effects. Moreover，different adsorbent dosages，pre-treatment methods，and matrix types had a significant impact on the matrix effects of each pesticide residue compound. Conclusion The impact of matrix effects on the detection results of various pesticide residues varies among different vegetable samples under two pre-treatment conditions. Although the detection method used in this study has good precision，low detection limit，and stable spiked recovery rate，it is still necessary to strengthen the elimination of matrix effects to ensure the accuracy and reliability of the results.

Key words: Pesticide residues, Ultra-high performance liquid chromatography-mass spectrometry, Matrix effect