BACKGROUND Propiconazole is widely used to control fungal diseases in field crops including celery and onion. The potential risk to the environment and human health has aroused much public concern. Therefore, it is significant to investigate the degradation behaviour, residue distribution and dietary risk assessment of propiconazole in celery and onion. RESULTS A sensitive analytical method for determination of propiconazole residue in celery and onion was established and validated through high performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS). The average recovery rate of propiconazole ranged from 85.7% to 101.8% with the relative standard deviation (RSD) of 2.1-6.3%. For the dissipation kinetics, the data showed that propiconazole in celery and onion was degraded with the half-lives of 6.1-6.2 days and 8.7-8.8 days, respectively. In the terminal residue experiments, the residues of propiconazole were below 4.66 mg/kg in celery after application of 2-3 times and were below 0.029 mg/kg in onion after application of 3-4 times with an interval of 14 days under the designed dosages. The chronic and acute dietary exposure assessment for propiconazole were valued by risk quotient (RQ) and the result manifested that all of the RQ values were lower than 100%. CONCLUSION Propiconazole in celery and onion was rapidly degraded following first-order kinetics models. The dietary risk of propiconazole through celery or onion was negligible to consumers. The study could not only offer a valuable reference for reasonable usage of propiconazole on celery and onion, but also facilitate the establishment of maximum residue limits (MRLs) in China. This article is protected by copyright. All rights reserved.

中文翻译：

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大田应用下芹菜和洋葱中丙环唑降解行为、残留分布及膳食风险评估研究

背景技术丙环唑广泛用于防治大田作物包括芹菜和洋葱的真菌病害。对环境和人类健康的潜在风险引起了公众的广泛关注。因此，研究丙环唑在芹菜和洋葱中的降解行为、残留分布和膳食风险评估具有重要意义。结果 建立了测定芹菜和洋葱中丙环唑残留的灵敏分析方法，并通过高效液相色谱串联质谱 (HPLC-MS/MS) 进行了验证。丙环唑的平均回收率为85.7%~101.8%，相对标准偏差（RSD）为2.1~6.3%。对于耗散动力学，数据显示芹菜和洋葱中的丙环唑降解，半衰期分别为 6.1-6.2 天和 8.7-8.8 天，分别。在末端残留试验中，在设计的2-3次施用后，芹菜中丙环唑的残留量低于4.66 mg/kg，间隔14天施用3-4次后，在洋葱中的残留量低于0.029 mg/kg。剂量。丙环唑的慢性和急性膳食暴露评估采用风险商（RQ）评估，结果表明所有风险商值均低于100%。结论 芹菜和洋葱中的丙环唑按照一级动力学模型迅速降解。消费者通过芹菜或洋葱摄入丙环唑的饮食风险可以忽略不计。该研究不仅可以为丙环唑在芹菜和洋葱上的合理使用提供有价值的参考，而且有助于我国建立最大残留限量（MRLs）。本文受版权保护。版权所有。