毛细管电泳法检测果汁中的抗坏血酸

Determination of Ascorbic Acid in Fruit Juice by Capillary Electrophoresis with Electrochemical Detection

采用电化学沉积将铂纳米颗粒固定到碳纤维微电极上,制备了一种新型铂纳米颗粒修饰微电极.将铂纳米颗粒修饰微电极与毛细管电泳联用,对抗坏血酸进行了检测.探讨了铂的电沉积时间、电位,氯铂酸的浓度,缓冲溶液pH、浓度,检测电势和分离电压等对该电极的影响.实验结果表明,该电极对抗坏血酸的线性范围为1.0×10-6～8.0×10-6 mol/L和8.0×10-6～1.0×10-3 mol/L,相关系数分别为0.998 1和0.999 2,信噪比为3时,检出限为8.0×10-7 mol/L.利用该电极实现了果汁中抗坏血酸的定量检测.

In this paper, the Pt nanoparticles（PtNPs）are electrodeposited on the surface of a self made assembled carbon fiber micro-disk bundle electrode（CFME）. Ascorbic acid（AA）is detected by capillary zone electrophoresis with electrochemical detection at the electrode. Under optimized experimental conditions,the concentration linear range of AA is from 1.0×10-6 to 8.0×10-6 mol/L and 8.0×10-6 to 1.0×10-3 mol/L with correlation coefficients of 0. 998 1 and 0. 999 2. When the signal-to-noise ratio is 3,the concentration limit of detection of AA is 8.0×10-7 mol/L. This method is successfully applied to detect AA in fruit juice.