Yi Fei, Guo Baoyuan, Peng Zhenlei, Li Haifang, Marriott Philip, Lin Jin-Ming
State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, P. R. China.
Electrophoresis. 2007 Aug;28(15):2710-6. doi: 10.1002/elps.200600705.
A fast, simple, and sensitive CE method was developed to study the separation and degradation of imazaquin enantiomers in field soils. The parameters pH and concentration of the buffer electrolyte, type and concentration of the chiral selectors, applied voltage, and temperature of the CE system were investigated. Sodium hydrogen phosphate (50 mM) at pH 10.1 containing 30 mM hydroxypropyl-beta-CD (HP-beta-CD) was found to be the suitable BGE. The reliable determination for imazaquin enantiomers was obtained at 20 kV applied voltage, 15 degrees C separation system, and detection at 214 nm. Under the optimal conditions, the LODs (S/N = 3) were 0.0097 and 0.0098 mg/kg; linearity ranged from 0.019 to 1.24 and 0.020 to 1.26 mg/kg for the first-eluting peak of imazaquin (imazaquin-I) and the second-eluting peak of imazaquin (imazaquin-II) in soil, respectively. The precision in terms of the percentage of RSD (%RSD) calculated from peak area was not greater than 5%. With the suitable characteristics of the present method, it was applied to the study of enantioselective degradation in field soil. According to the calculated values of the enantiomer ratio (ER) and the rate constant of degradation (k), the results suggested that the degradation rate of the two enantiomers were slightly different, and that the pH of the soil had a strong influence on the rate of degradation.
开发了一种快速、简单且灵敏的毛细管电泳方法，用于研究咪唑喹啉对映体在田间土壤中的分离和降解。研究了毛细管电泳系统的缓冲电解质的pH值和浓度、手性选择剂的类型和浓度、施加电压以及温度等参数。发现pH 10.1的50 mM磷酸氢二钠中含有30 mM羟丙基-β-环糊精（HP-β-CD）是合适的背景电解质。在20 kV施加电压、15℃分离系统和214 nm检测条件下，获得了对咪唑喹啉对映体的可靠测定结果。在最佳条件下，土壤中咪唑喹啉第一个洗脱峰（咪唑喹啉-I）和第二个洗脱峰（咪唑喹啉-II）的检测限（S/N = 3）分别为0.0097和0.0098 mg/kg；线性范围分别为0.019至1.24和0.020至1.26 mg/kg。根据峰面积计算的相对标准偏差百分比（%RSD）表示的精密度不大于5%。由于本方法具有合适的特性，将其应用于田间土壤对映体选择性降解的研究。根据对映体比率（ER）和降解速率常数（k）的计算值，结果表明两种对映体的降解速率略有不同，并且土壤pH值对降解速率有很大影响。
