碳糊电极阴极溶出伏安法测定当归中阿魏酸

采用碳糊电极作工作电极,阴极溶出伏安法对阿魏酸进行测定。在0.05mol.L-1盐酸溶液中,当有0.04mmol.L-1氯化钠溶液,0.004g.L-1十二烷基硫酸钠溶液存在时,1.1V(vs.SCE)富集180s,以100mV.s-1扫描速率从1.0V扫描至0V。阿魏酸在碳糊电极上于0.46V处产生一灵敏的阴极溶出伏安峰,峰电流与阿魏酸浓度在2.2×10-7～1.1×10-5 mol.L-1范围内呈线性关系,检出限(3S/N)为4.0×10-8 mol.L-1。初步探讨了阿魏酸的电化学性质,此方法用于测定当归中阿魏酸的含量,并以此样品为基体做回收试验,测得回收率在104.0%～109.1%之间,测定值的相对标准偏差(n=6)在2.6%～5.3%之间。

Cathodic Stripping Voltammetric Determination of Ferulic Acid in Chinese Angelica with Carbon Paste Electrode

Ferulic acid was determined by cathodic stripping voltammetry using carbon paste electrode as working electrode.In a 0.05 mol·L-1 HCl solution containing 0.04 mol·L-1 NaCl and 0.004 g·L-1 sodium laurylsulfonate,and by accumulation at 1.1 V(vs.SCE) for 180 s and scanning from 1.0 V to 0 V at the rate of 100 mV·s-1,a sensitive cathodic stripping voltammetric peak given by ferulic acid was observed at the carbon paste electrode at the potential of 0.46 V(vs.SCE).Linear relationship between values of peak current and concentration of ferulic acid was obtained in the range of 2.2×10-7-1.1×10-5mol·L-1,with detection limit(3S/N) of 4.0×10-8mol·L-1.A preliminary discussion on the electrochemical behavior of ferulic acid at the carbon paste electrode was given.This method was used in the determination of ferulic acid in sample of Chinese angelica,and using this sample as matrix,recovery was tested by standard addition method,giving results of recovery and RSD′s(n=6) in the ranges of 104.0%-109.1% and 2.6%-5.3% respectively.