高效毛细管电泳法测定利多卡因代谢产物单乙基甘氨酰二甲苯胺

Determination of monethylglycinexylidide,a metabolite of lidocaine,with high performance capillary electrophoresis

目的 :建立一种测定利多卡因代谢产物单乙基甘氨酰二甲苯胺 (MEGX)含量的高效毛细管电泳法。方法 :用50mmol/L硼酸缓冲液 (pH =8.8)为电泳电解液 ,电压 1 2kV ,运行电流 1 8.8～ 2 3 .2 μA ,检测波长 2 1 4nm ,有效毛细管长度 50cm ,管径 50 μm ,氨茶碱为内标 ,展开 1 2min。 8只昆明种小白鼠腹腔注射 0 .2 %利多卡因 4 0mg/kg ,用本法测定其 5h尿液中MEGX累积排泄量。结果 :MEGX迁移时间 7.8min ,氨茶碱迁移时间 1 0 .7min。MEGX含量为 0 .0 62～1 .0mg/ml时 ,其浓度与色谱峰面积线性关系良好 ,r =0 .9991 ,日内、日间变异系数均小于 7.8% ,回收率为98.4 %～ 1 0 1 .6% ,常用 3 0种药物对其无干扰。 8只小鼠MEGX累积排泄量为 ( 2 95.2± 55.2 ) μg ,其中游离型MEGX为 4 4.7% ,结合型为 55.3 %。结论 :该方法简单、快速、灵敏 ,特异性和重现性良好 ,具有较强实用价值。

OBJECTIVE:To develope a method for the determination of monoethylglycinexylidide(MEGX),a metabolite of lidocaine by high performance capillary electrophoresis.METHODS:50mmol/L obrate buffer,pH 8.8,was used as the electrophoresis solution.Electrophoresis was carried out with a constant voltage of 15kV and a current of 18.8～23.2μA and aminophylline as internal standard.The length of effective capillary was 50cm(DI 50μm).The detecting wavelength was 214nm,8 mice were administered 0.2% lidocaine 40mg/kg,ip.The content of MEGX in the urine collected for 5h was measured.RESULTS:The migration time of MEGX was 7.8min and that of aminophylline was 10.7min.The linear range was 62～1000μg/ml(r=0.9991) with relative standard deviations less than 7.8%.The total content of MEGX in the urine collected for 5h in mice was (295.2±55.2)μg,among which free MEGX was 44.7% and conjugated MEGX was 55.3%.CONCLUSION:The method was fast,convenient and sensitive.It was applied to assay MEGX in mouse urine and got satisfactory results.