Pesticide residues analysis is a complex task requiring the analyst to search for dozens, or even hundreds of compounds in a wide variety of food or environmental matrices. The research describes the use of QuEChERS to prepare 12 kinds of vegetables and fruits (tomato, celery, eggplant, leek, potato, white radish, bean, cabbage, grape, pear, orange and peach) for 273 pesticides residues analysis by GC-MS/MS. The method was validated in terms of recovery and reproducibility (n=6) and showed good linearity (R2 = 0.99) for the analytical curves prepared in respective matrix-matched solutions. The spike levels for the recovery experiments were 0.002, 0.005, 0.01, 0.02, 0.05, 0.1, 0.2 and 0.5 mg/kg for all the 12 kinds of vegetables and fruits. In this study, we first compared the recoveries between SPE and QuEChERS preparations in 0.002 mg/kg spike level. The compounds ranged from 60% to 120% in recovery, RSD6 matrix (total 12 matrix) were chosen and counted. P-value was calculated with Pearson's chi-square-test, threshold for significance was p>0.05. The result (p=0.660) indicates that the difference between these two preparations was not significant. Thus QuEChERS can be applied. Take the most complicated matrix leeks as an example, the results showed that 227 pesticides had good linear response (R2 = 0.99). The results of 0.005 mg/kg spike level showed that 93% of the above pesticides' recoveries were between 60%~120% and 92% of them the RSD were less than 15%. Adequate quantification and identity confirmation were attained, even at the lowest level, 83.1 % pesticides were with the good accuracies and precisions, as well as the good matches for the observed ion ratios. The method has been proven to be highly efficient and suitable for analyzing a wide range of pesticide combinations.

Method development and validation of gas chromatography coupled with triple quadrupole mass spectrometry (GC-MS/MS) for multi-residue analysis of 273 pesticides in fruits and vegetables using a QuEChERS approach

248th National Meeting (2014)

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