Abstract: A new method for screening pesticide residues in vegetables and fruits by multi-plug filtration cleanup (m-PFC) method combined with gas chromatography-quadrupole time of flight mass spectrometry (GC-QTOF-MS) was developed. The samples were extracted with acetonitrile, purified by m-PFC, and detected by GC-QTOF-MS. Qualitative analysis was carried out by retention time and accurate mass measurements in full scan mode and quantitation was performed using matrix-matched standard calibration, which could effectively eliminate matrix interference. Twelve typical samples (Chinese cabbage, celery, tomato, cucumber, spinach, Chinese leek, pakchoi, tangerine, pear, apple, grape, and orange) were used to evaluate the method. Good linearity was achieved for 234 pesticides in the concentration range of 5 to 500 μg/kg with correlation coefficients greater than 0.990. The results showed that the limits of detection of this method were in the range of 5–20 μg/kg. The average recoveries at three spiked levels of 10, 50, and 100 μg/kg were in the range of 73.2%–124.8%, 75.5%–122.6% and 74.8%–121.7%, with relative standard deviations (RSDs) of 2.4%–13.2%, 2.8%–11.4% and 2.2%–10.5%, respectively. The method could effectively improve the detection efficiency of high-resolution mass spectrometry for high throughput screening of pesticide residues in vegetables and fruits, thereby having great potential for practical application.

Key words: gas chromatography-quadrupole time of flight mass spectrometry; multi-plug filtration cleanup; pesticide residues; rapid screening; vegetables and fruits