毛细管电泳-电化学发光法检测淮山中乐果的残留量

Determination of Dimethoate in Yamby Capillary Electrophoresis Coupled with Electrochemiluminescence Detection

采用毛细管电泳-电化学发光（CE-ECL）法检测淮山中乐果的残留量。考察了检测电位、缓冲液浓度及其pH值、分离电压、进样电压和时间等实验参数对测定乐果的影响。在优化的实验条件下,乐果在0.50~10 000μg/L范围内与ECL强度呈良好线性,检出限为0.050μg/L。对0.500mg/L乐果溶液连续6次测定,峰高的相对标准偏差（RSD）为1.8%,迁移时间的RSD为1.0%。该方法用于淮山中乐果残留量的测定,加标回收率在98.3%~103.0%之间,RSD≤2.3%。

The capillary electrophoresis coupled with electrochemiluminescence detection method has been applied to the determination of dimethoate in yam.The effects of detection potential,pH and concentration of buffer,separation voltage,injection voltage and time were investigated.Under optimum conditions,a baseline separation and highly sensitive detection for dimethoate was achieved.The ECL intensity was in proportion to dimethoate concentration in the range from 0.50 to 10 000μg/L with the detection limit（S/N=3）of 0.05μg/L.The relative standard deviation of the ECL intensity of dimethoate was 1.8%,and the relative standard deviation of the migration time of dimethoate was 1.0%for six continuous injections of 0.500mg/L dimethoate standard solution,respectively.The method was successfully applied to dimethoate assay in samples of yam.The spiked recoveries were in the range of 98.3%-103.0%,with relative standard deviations less than 2.3%.