β-环糊精修饰电极直接测定肾上腺素注射液的含量

Direct determination of epinephrine content in injection with β-cyclodextrin modified electrode

目的:研究肾卜腺素(EP)在β-环糊精修饰聚乙酰苯胺玻碳电极(β-CD/PNAANI/GCE)上的电化学行为,建立一种新的测定 EP 的电化学分析方法。方法:用循环伏安法研究 EP 在修饰电极上的氧化还原特性,用差分脉冲伏安法直接测定肾上腺素的含量。结果:该修饰电极能很好地催化 EP,与裸玻碳电极(GCE)相比,还原峰电流增强近30倍。在 pH 7.5磷酸盐缓冲液中,还原峰电流与 EP 的浓度在6.0×10^(-6)～1.0×10^(-4) mol·L^(-1)范围内呈良好的线性关系,其线性回归方程为 I_p=1.68+6.92×10^(-6)C_(EP),相关系数为0.9975,检测限为1.0×10^(-7)mol·L^(-1)。回收率在97.5%～104.5%之间。结论:该方法操作简单,可用于注射液中盐酸肾上腺素含量的测定,结果令人满意。

Objective：To investigate the electrochemical behaviors of epinephrine （EP） at theβ- cyclodextrin modified poly（N- acetylaniline） （PNAANI） glassy carbon electrode （GCE） （β- CD/PNAANI/GCE） and establish a novel electroanalytical technique for the determination of EP. Methods：The redox characteristics of epinephrine （EP） at the modified electrode were investigated by cyclic vohammetry （CV）. Epinephrine content was determined by differential pulse vohammetry （DPV）. Results： Theβ - cyclodextrin modified electrodes showed an excellent electrocatalytic activity for the reduction of epinephrine （EP）. The reduction peak height of EP was almost increased by 30 times compared with the bare glassy carbon electrode. In pH 7.5 phosphate buffer solution （ PBS）, the cathodic current increased linearly with the concentration of EP in the range of 6.0 × 10^-6 - 1.0 × 10^ -4 mol · L^-1. The linear regression equation was Ip = 1.68 ＋6.92 × 10^-6 CEP ,with correlation coefficient of 0. 9975. The detection limit was 1.0 × 10 ^-7 mol ·L^-1 with a good recovery between 97.5% and 104. 5%. Conclusion： The proposed method is simple, sensitive and reproducible and is applied to measure the content of epinephrine in injection.