电化学电流校正法定量测定五羟色胺

Quantitative Determination of 5-HT by Electrochemical Current-correction Method

制备了碳纤维超微电极,将其在1.0×10^(-4)mol/L五羟色胺溶液中循环伏安扫描10圈后,测定电极在铁氰化钾、多巴胺等电活性溶液中的循环伏安以及差分脉冲的峰电流变化,结果表明五羟色胺对碳纤维超微电极有毒化效应.采用火焰灼烧法对被五羟色胺毒化的电极进行活化,以电极在1.0×10^(-3)mol/L铁氰化钾溶液中的峰电流为基准,活化后电极与原电极在铁氰化钾溶液中的峰电流之比为校正因子,对电极的活性面积进行校正.实验结果表明,校正后的五羟色胺氧化峰电流与其浓度在1.0×10^(-6)~2.0×10^(-4)mol/L范围内呈现良好的线性关系,线性回归方程为I=0.2073c+0.3074,相关系数R^2=0.9962.采用该方法对五羟色胺样品浓度进行了测定,回收率达到98.0%~102.4%.

In this paper,the carbon fiber ultramicroelectrode（CFUME）was prepared,after cyclic voltammetry scanning in 1.0×10（-4）mol/L 5-hydroxytryptamine（5-HT）,and the electrochemical behaviors of the electrode in ferricyanide and dopamine（DA）were investigated.The experimental results show that the surface of carbon fiber ultramicroelectrode has been passivated by the oxidation products of hydroxytryptamine.The carbon fiber of the deteriorated ultramicroelectrodes was burned in the faint flame to activate the surface,and the peak current ratio of the activated electrode and the new electrode in 1.0×10（-3）mol/L ferricyanide solution as the correction factor,the active area of the electrode is corrected by dividing the correction factor.The experimental results show that corrected peak current and concentration of 5-HT in the range of 1.0×10（-6）—2.0×10（-4）mol/L show a good linear relationship,and the liner regression equation is I=0.2073c＋0.3074,with the related coefficient of R2=0.9962.The concentration of 5-HT was determined by this method and the recovery is 98.0%—102.4%.The method is simple and reproducible,and may be used to detect 5-HT in biological sample.