Simultaneous Determination of Nine Pesticide Residues in Plant-derived Foods by QuEChERS Coupled with High-performance Liquid Chromatography-triple Quadrupole Mass Spectrometry

Abstract:

An improved QuEChERS method was established and combined with high-performance liquid chromatography-triple quadrupole mass spectrometry (HPLC-MS/MS) for the simultaneous detection of nine new pesticide residues, including formetanate hydrochloride, cyclaniliprole, and pyflubumide, in plant-based foods. In the national standards of China for plant-based food safety, the detection standards for these nine pesticide residues are not yet established. However, when fruits and vegetables are exported to the European Union (EU) and Japan, pesticide residues are one of the main targets in food safety testing. Firstly, methyl cyanide is used for extraction, followed by water removal using magnesium sulfate (anhydrous) and sodium chloride. Subsequently, the supernatant is purified with 150 mg of N-propyl ethylenediamine and 900 mg of magnesium sulfate (anhydrous). Finally, HPLC-MS/MS is used for pesticide residue detection. The results suggest that all nine pesticide substances show good linear relationships at 0.000 2~0.02 mg/L, with correlation coefficients (r2) exceeding 0.998. The limit of detection (S/N=3) is 0.028~1.493 μg/kg, and the limit of quantification (S/N=10) is 0.093~4.975 μg/kg. At spiked levels of 5, 10, and 20 μg/kg, the average recovery rates are 70.60%~108.75%, and the relative standard deviations (n=6) are 1.35%~12.99%. The results all comply with the standards for pesticide residue limits in fruits and vegetables set by EU countries and Japan. This study offers a reference method for the import and export inspection of such pesticides in plant-based foods originating from China.