Optimized QuEChERS method in determination of multiresidues on high-risk leafy vegetables and monitoring data analysis from 2021 to 2023
Pesticide pollution poses significant risks to human health, ecosystem, and biodiversity. Among agro-products, leafy vegetables exhibited particularly severe pesticide residue due to their short harvest periods and large leaf surfaces. However, investigations on multiresidues in high-risk leafy vegetables based on Chinese dietary habits were still limited. In this study, we developed a weak basic citrate-buffered QuEChERS method for the simultaneous extraction of 43 pesticides in bok choy, celery, Chinese chive and cilantro. Coupled with the high-throughput UPLC-MS/MS technique, this method achieved LODs ranging from 0.1–3.0 μg/kg and LOQs ranging from 0.4–10.0 μg/kg for the four matrices with high sensitivity. The recovery experiments on blank samples indicated that the method recoveries were in the range of 76.2 %–116.3 %, with RSDs less than 12.1 %. The developed method provided a highly accurate and precise technical approach for the analyses of high-risk leafy vegetables. Furthermore, 211 vegetables were collected from markets in Hangzhou from 2021 to 2023. The total detection frequency was 92.9 %, and high detection frequencies for pesticides such as acetamiprid, carbendazim, clothianidin, dimethomorph, dinotefuran, imidacloprid, propiconazole, pyraclostrobin, and thiamethoxam. The distribution of pesticides in different vegetables varied significantly due to factors such as application amount and plant absorption, providing valuable insights for implementing targeted detection and regulatory interventions. The mixed use of multiple pesticides in cilantro was observed. Combined use of pesticides such as tebuconazole, difenoconazole, and propiconazole (all belonged to sterol demethylation inhibitors), might lead to pathogen resistance. In summary, the frequently detected pesticides in the four leafy vegetables presented acceptable dietary risks, with hazard quotients ranging from 0.005 % to 3.634 %.
危险品化学品经营许可证（带存储）