Department of Analytical Chemistry, Faculty of Chemistry, University of Alcalá, Madrid, Spain.
J Chromatogr A. 2011 Jul 29;1218(30):4877-85. doi: 10.1016/j.chroma.2010.12.116. Epub 2011 Jan 5.
The enantiomers of two acylamine fungicides (metalaxyl and benalaxyl) were separated by EKC using CDs as chiral selectors. The use of 15 mM succinyl-γ-CD for metalaxyl and 5 mM succinyl-β-CD for benalaxyl dissolved in a 50 mM 2-morpholinoethanesulfonic acid buffer (pH 6.5), enabled the chiral separation of metalaxyl enantiomers in 11.5 min with a resolution of 3.1 and the enantiomeric separation of benalaxyl in 7.5 min with a resolution close to 15. Under these conditions, the two enantiomers of each of the chiral compound studied were also separated from folpet, very commonly present in fungicide formulations containing metalaxyl or benalaxyl. The analytical characteristics of the two developed methods were studied in terms of precision, linearity, selectivity, limits of detection (LODs) and limits of quantitation (LOQs) showing their suitability for the determination of these compounds in commercial agrochemical formulations. Finally, the development of an in-capillary preconcentration strategy allowed the detection of enantiomeric impurities up to 1.2% in commercial products labeled as enantiomerically pure in metalaxyl-M.
两种酰胺类杀菌剂（甲霜灵和苯霜灵）的对映异构体通过使用手性选择剂 CD 的 EKC 进行了分离。在 50mM 2-吗啉乙磺酸缓冲液（pH6.5）中，使用 15mM 琥珀酰基-γ-CD 溶解甲霜灵和 5mM 琥珀酰基-β-CD 溶解苯霜灵，实现了甲霜灵对映异构体在 11.5 分钟内的手性分离，分辨率为 3.1，苯霜灵的对映体分离在 7.5 分钟内，分辨率接近 15。在这些条件下，研究的每种手性化合物的两种对映异构体也从福美双中分离出来，福美双通常存在于含有甲霜灵或苯霜灵的杀菌剂制剂中。根据精密度、线性、选择性、检测限（LOD）和定量限（LOQ）研究了这两种开发方法的分析特性，表明它们适用于商业农用化学品制剂中这些化合物的测定。最后，开发了一种在毛细管内浓缩策略，允许检测到商业产品中对映体杂质高达 1.2%，这些产品在甲霜灵-M 中被标记为对映体纯。
