Enantioseparation of Vinclozolin by γ-Cyclodextrin-Modified Micellar Electrokinetic Chromatography

Abstract

Cyclodextrin-modified micellar electrokinetic chromatography was applied to the enantioseparation of vinclozolin, which has been used as a fungicide and has an anti-androgenic activity, using gamma-cyclodextrin together with sodium dodecyl sulfate. Factors affecting the chiral resolution and migration time of vinclozolin were studied. The optimum running conditions were found to be 20 mM phosphate-5 mM borate buffer (pH 8.5) containing 50 mM gamma-cyclodextrin and 100 mM sodium dodecyl sulfate with an effective voltage of 20 kV at 20 degrees C using direct detection at 203 nm. Under these conditions, the resolution (Rs) of racemic vinclozolin was approximately 2.1. The sample was concentrated by solid-phase extraction and was fractionated by HPLC. The peak area ratio of (+)- and (-)-vinclozolins in wine was found to be 2:3, namely, not racemic, suggesting that degradation rates were different between (+)- and (-)-vinclozolins. The anti-androgenic activities of (+)- and (-)-vinclozolins on dihydrotestosterone-induced transcription were also investigated. The anti-androgenic activity of (+)-vinclozolin tended to be stronger than that of (-)-vinclozolin, suggesting the possibility that vinclozolin can act as an enantioselective anti-androgen.

Sensitive chiral analysis by capillary electrophoresis

“…Thus, the detection from 3610 28 to 5610 26 M of different drugs in plasma [64], serum [65], and urine [66,67] has been performed. In addition, the detection up to 10 210 or 10 27 M of phenoxy acid herbicides in spiked water samples [68,69] as well as the detection of the pesticides vinclozolin (,10 26 M), maleic hydrazide and imazalil (3610 27 M), in beverages and vegetables [70][71][72] has been achieved. Offline LLE has been employed for the extraction and preconcentration of drugs in biological samples and pollutants in culture media.…”

Chiral analysis of pollutants and their metabolites by capillary electromigration methods

“…1 some structures of these phenoxy acids). One important detail that should be realized from Table 1 is that only few of these works deal with CE enantioseparation of pollutants in real matrixes (e.g., wine [52], water [24,33,43], or soil [22,38]), most of the studies being carried out with pure standards. A possible explanation can be the relatively low sensitivity of CE; this limitation makes the direct application of CE to real life samples difficult since pesticides are usually in very low concentrations there.…”

“…Recently, Kodama et al [52] have analyzed vinclozolin in wine, a dicarboximide fungicide widely used in Europe to protect fruits, vegetables, ornamentals, and turf grasses. In order to achieve the chiral separation of vinclozolin enantiomers by MEKC-UV, several CDs (2,6- (HP-g-CD), and g-CD) were tested in the separation buffer that contained SDS, phosphate, and borate.…”

Chiral Capillary Electrophoresis of Agrochemicals in Real Samples

“…CDmodified MEKC was applied to the enantioseparation of vinclozolin in wine using γ -CD together with sodium dodecyl sulfate. 19) The peak area ratio of (+)-and (-)-vinclozolins was found to be 2 : 3, suggesting that the degradation rate of (+)-vinclozolin was greater than that of (-)-vinclozolins. The anti-androgenic activity of (+)-vinclozolin tended to be stronger than that of (-)-vinclozolin, suggesting the possibility that vinclozolin can act as an enantioselective anti-androgen.…”