用基于1.5次微分伏安法及小波信号处理的毛细管电泳分离检测混合氨基酸

Determination of amino acids by capillary electrophoresis with the 1.5th-differential voltammetric electrochemical detection system and wavelet transform

以铜圆盘电极为工作电极,利用毛细管电泳-1.5次微分伏安法检测系统,在10 mmol/L混合磷酸盐缓冲溶液中,对3种氨基酸（色氨酸、组氨酸、苏氨酸）的分离检测条件进行了研究,采用小波技术,对含有高频扫描响应信号的复合信号进行分离和重构,获得电泳分离图谱。研究结果表明：在1.67×10^-3-2.17×10^-6mol/L范围内可达r≥0.995的良好线性,该方法对苏氨酸、色氨酸和组氨酸的检出限分别可达1.91×10^-8、3.05×10^-7和2.50×10^-7mol/L。

Three kinds of amino acids （tryptophane, histidine and threonine） were detected by using the 1.5th-differential Voltammetric electrochemical detection system and wavelet transform, with a 75μm× 50 cm fused-silica capi- llary electmphoresis. The optimum conditions for separation were studied. And under the conditions of 10 mmol/L Na2HPO4-Na3PO4 （pH = 11.03） running electrolyte, 15 kV separation voltage, scanning potential from 0.2 to 1.0 V, a good reproducibility and good linearity （r≥0.995） separation was obtained from the complex signals in the range of 1.67×10^-3 - 2.17 ×10^-6 mol/L. And the detection limits （S/N = 3） were got as threonine 1.91 ×10^-6 mol/L, tryptophane 3.05 ×10^-7 mol/L, histidine 2.50×10^-7 mol/L.