Chiral stability of synthetic pyrethrold insecticides
Chiral stability of synthetic pyrethrold insecticides
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DOI：
10.1021/jf048425i
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发表时间：
2005-05-18
影响因子：
6.1
通讯作者：
Gan, JY
中科院分区：
文献类型：
--
作者：
Liu, WP;Qin, SJ;Gan, JY
合成拟除虫菊酯是由多个立体异构体组成的手性化合物。对映体在环境归宿和生态毒性方面的选择性评价需要在分析过程中保持立体异构体完整性的分析方法。在这项研究中，我们的特点是稳定性的立体异构体从四个常用的拟除虫菊酯，顺式联苯菊酯（顺式-BF），二氯苯醚菊酯（PM），氯氰菊酯（CP），氟氯氰菊酯（CF），在气相色谱（GC）分析和样品制备。顺式-BF和PM的立体异构体被发现是稳定的，但CP和CIF的立体异构体是不稳定的，在加热或在水中。异构体转化仅发生在CIP或CF中的aC处，导致分析物立体异构体转化为差向异构体。在260 ° C的GC入口温度下，CIP和CF发生约9%的转化率。在有机溶剂和无菌水中，顺式-BF和PM的立体异构体是稳定的，但在环境温度下观察到CP和CF在水中的缓慢异构体转化。然而，当GC入口温度保持在30 ℃时，CP和CF的异构体转化率相对不显著（2-3%）。
Synthetic pyrethroids are chiral compounds consisting of multiple stereoisomers. Evaluation of enantioselectivity in environmental fate and ecotoxicity requires analytical methods that preserve stereoisomer integrity during analysis. In this study, we characterized the stability of stereoisomers from four commonly used pyrethroids, cis-bifenthrin (cis-BF), permethrin (PM), cypermethrin (CP), and cyfluthrin (CF), during gas chromatography (GC) analysis and sample preparation. Stereoisomers of cis-BF and PM were found to be stable, but those of CP and CIF were unstable, under heat or in water. Isomer conversion occurred only at the aC in CIP or CF, causing the analyte stereoisomer to convert to an epimer. At a GC inlet temperature of 260 degrees C, about 9% conversion occurred for CIP and CF. In organic solvents and sterile water, stereoisomers of cis-BF and PM were stable, but slow isomer conversion was observed for CP and CF in water at ambient temperature. However, isomer conversion for CP and CF was relatively insignificant (2-3%) when the GC inlet temperature was kept at