HPLC–MS/MS enantioseparation of triazole fungicides using polysaccharide‐based stationary phases

Abstract

The enantiomeric separation of 21 triazole fungicides was carried out on four polysaccharide-derived chiral stationary phases in the reversed phase separation mode using high performance liquid chromatography coupled with tandem mass spectrometry. All fungicides were detected in electrospray ionization (ESI) positive mode with selected reaction monitoring (SRM). Complete enantioseparation was achieved for 21 fungicides except for difenoconazole based on cellulose tris (3,5-dimethylphenylcarbamate) and cellulose tris (3-chloro-4-methylphenyl carbamate) columns by optimizing experimental conditions including mobile phase and column temperature. Mobile phase was 0.1% formic acid aqueous solution mixed with methanol or acetonitrile in different proportions. Among all the fungicides, 15 with two enantiomers and three with four stereoisomers (bitertanol, bromuconazole, and cyproconazole) were successfully separated at 25°C. Enantioseparation for the other three fungicides (propiconazole, triadimenol, and difenoconazole) with four stereoisomers could be achieved by changing the column temperature from 10 to 40°C. Propiconazole and triadimenol were enantioseparated on baseline at 40 and at 35°C, respectively, and difenoconazole was enantioseparated partially with the R(s) > 1.1 at 25°C. Moreover, linearities and limits of detection (LODs) of 21 fungicides except for difenoconazole were studied, showing coefficients of determination (R(2)) higher than 0.99 and LODs lower than 2.5 μg/L.

Enantiomeric Separation of Chiral Pesticides by Permethylated β‐Cyclodextrin Stationary Phase in Reversed PhaseLiquid Chromatography

“…Under reversed phase conditions, the enantioselective separation of tebuconazole was investigated on various types of CSPs including cellulose tris (3-chloro-4methylphenylcarbamate) (Lux Cellulose-2), 14 amylose-tris (5-chlorine-2-methylphenylcarbamate) (Lux amylose-2), 15 and cellulose tris-(4-methylbenzoate) (Lux Cellulose-3). 16 In our study, the best resolution (Rs = 1.84) of two enantiomers of tebuconazole was accomplished when the content of methanol decreased to 55%, although complete separation can be achieved in 65% methanol. The resolution on permethylated β-cyclodextrin was close to the results of Lux Cellulose-2, and tebuconazole got a better separation on Lux Cellulose-3, compared with other types of CSPs.…”

Enantiomeric separation of prothioconazole and prothioconazole‐desthio on chiral stationary phases

“…Determination of prothioconazole and prothioconazole-desthio using HPLC and ultra performance liquid chromatographytandem mass spectrometry (UPLC-MS/MS) has been reported in animal food, soil, and wheat. 33 Simultaneous chiral separations of prothioconazole and prothioconazole-desthio to reduce analysis time and workload are urgently needed. 33 Simultaneous chiral separations of prothioconazole and prothioconazole-desthio to reduce analysis time and workload are urgently needed.…”

Comparative studies of immobilized chiral stationary phases based on polysaccharide derivatives for enantiomeric separation of 15 azole compounds

“…From the 15 analytes separated in this paper, the chiral separations of sertaconazole, butoconazole, flutrimazole, and intermediate are reported for the first time. In cases of other 11 analytes, their enantioseparations have been published using HPLC , supercritical fluid chromatography or CE . In these reports, a wide range of polysaccharide‐based CSPs have been used for enantiomeric resolution in HPLC.…”