Enantioselective Analysis and Degradation Studies of Four Stereoisomers of Difenoconazole in Citrus by Chiral Liquid Chromatography-Tandem Mass Spectrometry
Enantioselective Analysis and Degradation Studies of Four Stereoisomers of Difenoconazole in Citrus by Chiral Liquid Chromatography-Tandem Mass Spectrometry
复制标题
手性液相色谱-串联质谱对柑橘中苯醚甲环唑四种立体异构体的对映选择性分析及降解研究
DOI：
10.1021/acs.jafc.0c05938
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发表时间：
2021-01-04
影响因子：
6.1
通讯作者：
Zhang, Yuping
中科院分区：
文献类型：
--
作者：
Song, Qingmei;Wang, Ye;Zhang, Yuping
四种异丙康唑立体异构体在超手性S-OX色谱柱上被很好地分离。用x -射线单晶衍射证实了用手性柱有序洗脱的四种立体异构体的绝对构型分别为（2S,4S）、（2S,4R）、（2R,4R）和(2R,4S)-二苯醚康唑。首次建立了一种简单高效的HPLC-MS/MS法测定植物样品中异虫康唑四种立体异构体残留量的痕量检测方法。加样回收率为78.23 ~ 104.38%，rsd为0.33 ~ 9.95%。4种异虫康唑对映体的检出限为0.0002 ~ 0.0004 mg/kg，柑橘叶片和全果的定量限为0.0044 ~ 0.011 mg/kg。4种立体异构体在湖南和贵州柑橘叶片和全果中降解无明显的对映选择性。在广州，(2R,4R)-二苯醚康唑的降解速率是四种二苯醚康唑立体异构体中最慢的。
Four difenoconazole stereoisomers were well separated on a Superchiral S-OX column. The absolute configurations of the four stereoisomers of difenoconazole eluted in an orderly fashion with the chiral column were confirmed as (2S,4S), (2S,4R), (2R,4R), and (2R,4S)-difenoconazole, respectively, by single-crystal X-ray diffraction. For the first time, a simple and efficient trace detection method for the determination of residues of the four stereoisomers of difenoconazole in a plant sample by HPLC-MS/MS was developed. The mean recoveries were 78.23-104.38% with RSDs of 0.33-9.95%. The limits of detection for the four difenoconazole enantiomers were 0.0002-0.0004 mg/kg, and the limits of quantitation were 0.0044-0.011 mg/kg in citrus leaves and whole fruits. There was no obvious enantioselectivity upon degradation of the four stereoisomers in citrus leaves and whole fruits in Hunan and Guizhou. In Guangzhou, the rate of degradation of (2R,4R)-difenoconazole was the slowest among the four stereoisomers of difenoconazole.