小型化毛细管电泳-电化学检测法测定猪尿和猪饲料中的β-兴奋剂

Determination of β-adrenergic agonists in pig urine and pig fodder using miniaturized capillary electrophoresis with electrochemical detection

采用小型化毛细管电泳-电化学检测技术测定了猪尿和猪饲料中的克伦特罗（clenbuterol,俗称瘦肉精）及其替代品莱克多巴胺（ractopamine）和沙丁胺醇（salbutamol）。考察了工作电极的氧化电位、运行缓冲液的酸度和浓度、分离电压和进样时间等因素对分离和检测的影响。以直径300μm的碳圆盘电极为工作电极,检测电极电位为＋0.95V（vsSCE）,在100mmol/L的硼酸盐（pH9.15）运行缓冲液中,上述3种组分在7min内实现了较好的分离。被测物浓度与峰电流在3个数量级范围内呈良好的线性关系,检测限为1.20×10^-7-2.06×10^-7g/mL。该方法简单可靠,已成功应用于猪尿和猪饲料样品中3种β-兴奋剂的测定,是一种有效的食品安全分析检测方法。

A method of miniaturized capillary electrophoresis with electrochemical detection has been developed for the determination of β-adrenergic agonists in pig urine and pig fodder.Several important factors,including running buffer acidity,separation voltage,working electrode potential,etc.,were evaluated to acquire optimum analysis conditions.Under the selected optimum conditions,these analytes can be well separated in 7 min.Good linear relationship was established between the peak current and the concentration of each analyte over 3 orders of magnitude.The detection limits ranged from 1.20×10-7 to 2.06×10-7 g/mL（S/N=3）.The proposed method has been successfully applied for the determination of β-adrenergic agonist in pig urine and pig fodder with satisfactory results,providing a useful monitoring method for food safety.