Simultaneous determination of 43 kinds of fungicides in fruits and vegetables by high performance liquid chromatography-triple quadrupole linear ion trap mass spectrometry

[Objective] This study aims to realize the simultaneous determination of fungicide residues in vegetables and fruits. [Methods] A liquid chromatography-tandem quadrupole composite linear ion TRAP-mass spectrometry (LC-QTRAP-MS/MS) method was established for the simultaneous determination of fungicide residues in fruits and vegetables. The samples were salted out with sodium acetate and anhydrous magnesium sulfate in an acetonitrile solution containing 0.1% acetic acid, magnesium sulfate, ethylenediamine-n-propyl silanized silica gel (PSA), octadecylsilane bonded silica gel (HC-C₁₈) and multi-walled carbon nanotubes (MWCNTs) were used for purification. Mass spectrometry was conducted utilizing the enhanced ion scanning mode (MRM-IDA-EPI) and spectral library retrieval technology. The compounds were quantified using an external standard approach, comparing the retention time, ion pairs, and EPI spectral library retrieval. [Results] The 43 kinds of fungicides had a good linear relationship in the mass concentration range of 0.2~5.0 μg/L and 2.5~50.0 μg/L (<i>R²</i>>0.99). The limit of detection (LOD) was 0.1~5.0 μg/kg, and the limit of quantification (LOQ) was 0.4~10.0 μg/kg. The recoveries of the 43 kinds of fungicides were 65.1%～119.8% at three concentration levels, and the relative standard deviations were 0.8%～13.0%. [Conclusion] The established method is rapid, simple, and highly qualitative, and can be used for the screening, confirming and quantitative detection of 43 kinds of fungicides in fruits and vegetables.