He Lifei, He Falin, Yang Song, Gao Yangyang, Li Beixing, Liu Feng, Mu Wei
Key Laboratory of Pesticide Toxicology and Application Technique, College of Plant Protection, Shandong Agricultural University, Tai'an,, Shandong, 271018, People's Republic of China.
Research Center of Pesticide Environmental Toxicology, Shandong Agricultural University, Tai'an, Shandong, 271018, People's Republic of China.
Environ Sci Pollut Res Int. 2021 Apr;28(14):17712-17723. doi: 10.1007/s11356-020-11798-6. Epub 2021 Jan 5.
Pyraclostrobin (PYR), a fungicide of the strobilurin class, is used to control many different kinds of fungal diseases in greenhouses and on agricultural fields. In the present study, an efficient method was established for simultaneously determining PYR and its metabolite BF 500-3 in cucumber fruits, leaves, and soil matrices using QuEChERS pretreatment coupled with ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). The residue levels and dissipation kinetics of PYR were determined under greenhouse conditions. The recoveries ranged from 89.8 to 103.6% with relative standard deviations (RSDs) of 3.6-7.5% at three spiking levels. The results demonstrated that PYR dissipated quickly in the cucumber field with half-lives (DT) of 2.14-4.17 days on different sites and in different matrices. The residue of its metabolite BF 500-3 was very low and showed a trend of first increasing and then decreasing. The degradation rate of PYR in soil was the fastest, followed by that on cucumber fruits and leaves. The terminal residue of PYR at an application rate of 150 g a.i. ha (the maximum recommended rate) in cucumber fruits was below the maximum residue limit (MRL) of 0.5 mg/kg established in China. However, the application of the fungicide at 225 g a.i. ha (1.5× the maximum recommended rate) resulted in residues that were above the MRL 1 day after the final application, which is an unacceptable risk. Therefore, the application dosage of PYR at the recommended rates was safe to human beings and animals.
吡唑醚菌酯（PYR）是一种甲氧基丙烯酸酯类杀菌剂，用于防治温室和农田中的多种真菌病害。在本研究中，建立了一种高效方法，采用QuEChERS预处理结合超高效液相色谱 - 串联质谱法（UHPLC-MS/MS）同时测定黄瓜果实、叶片和土壤基质中的PYR及其代谢物BF 500-3。在温室条件下测定了PYR的残留水平和消解动力学。在三个加标水平下，回收率为89.8%至103.6%，相对标准偏差（RSD）为3.6 - 7.5%。结果表明，PYR在黄瓜田中消解迅速，在不同部位和不同基质中的半衰期（DT）为2.14 - 4.17天。其代谢物BF 500-3的残留量非常低，呈现先升高后降低的趋势。PYR在土壤中的降解速度最快，其次是在黄瓜果实和叶片上。在黄瓜果实中，以150 g a.i./ha（最大推荐用量）施药时，PYR的最终残留量低于中国规定的0.5 mg/kg最大残留限量（MRL）。然而，以225 g a.i./ha（1.5倍最大推荐用量）施药时，末次施药1天后残留量高于MRL，存在不可接受的风险。因此，按照推荐用量施用PYR对人和动物是安全的。
