title: Enantioselective determination of triazole fungice tetraconazole by chiral high-performance liquid chromatography and its application to pharmacokinetic study in cucumber, muskmelon, and soils.
abstract: A simple chiral high-performance liquid chromatography method with diode array detector was developed and validated for stereoselective determination of tetraconazole enantiomers in cucumber, muskmelon, and soils. Good separation was achieved at 20°C using cellulose tris-(4-methylbenzoate) as chiral stationary phase, a mixture of n-hexane and ethanol (90:10) as mobile phase at a flow rate of 0.8 ml/min. The assay method was linear over a range of concentrations (0.5-50 μg/ml) and the mean recoveries in all samples were more than 85% for the two enantiomers. The limits of detection for both enantiomers in plant and soil samples were 0.06 and 0.12 μg/g, respectively. Then, the proposed method was successfully applied to the study of enantioselective degradation of rac-tetraconazole in cucumber, muskmelon, and soils. The results showed that the degradation of two enantiomers of tetraconazole followed first-order kinetics and significantly stereoselective behavior was observed in cucumber, muskmelon, and Beijing soil. The preferential absorption and degradation of (-)-S-tetraconzole resulted in an enrichment of the (+)-R-tetraconazole residue in plant samples, whereas the (+)-R-tetraconazole showed a faster degradation in Beijing soil and the stereoselectivity might be caused by microorganisms. No stereoselective degradation was observed in Heilongjiang soil.
authors.affiliation: Pesticide Residues and Environmental Toxicology Group, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Key Laboratory of Pesticide Chemistry and Application, Ministry of Agriculture, Beijing 100193, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Li
authors.forename: Fengshou
authors.initials: F
authors.lastname: Dong
authors.forename: Jun
authors.initials: J
authors.lastname: Xu
authors.forename: Xingang
authors.initials: X
authors.lastname: Liu
authors.forename: Yuanbo
authors.initials: Y
authors.lastname: Li
authors.forename: Weili
authors.initials: W
authors.lastname: Shan
authors.forename: Yongquan
authors.initials: Y
authors.lastname: Zheng
mesh_terms: D002722:Chlorobenzenes / Q000032:analysis* / Q000737:chemistry / Q000302:isolation & purification / Q000493:pharmacokinetics*; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D028463:Cucumis melo / Q000737:chemistry / Q000378:metabolism*; D018553:Cucumis sativus / Q000737:chemistry / Q000378:metabolism*; D005659:Fungicides, Industrial / Q000032:analysis / Q000737:chemistry / Q000302:isolation & purification / Q000493:pharmacokinetics; D015203:Reproducibility of Results; D012987:Soil / Q000737:chemistry*; D013237:Stereoisomerism; D014230:Triazoles / Q000032:analysis* / Q000737:chemistry / Q000302:isolation & purification / Q000493:pharmacokinetics*; D005466:Fluorocarbons
chemical_list: D002722:Chlorobenzenes; D005659:Fungicides, Industrial; D012987:Soil; D014230:Triazoles; C524826:tetraconazole; D005466:Fluorocarbons