磷酸盐活化玻碳电极应用于肾上腺素的伏安测定
Use of Phosphate Activated Glassy Carbon Electrode in Voltammetric Determination of Epinephrine
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摘要: 采用循环伏安法制备了磷酸盐活化玻碳电极,研究了在pH 6.0磷酸盐缓冲介质中肾上腺素在磷酸盐活化玻碳电极上的电化学行为,建立了循环伏安法测定痕量肾上腺素的方法,该方法可有效地排除抗坏血酸对肾上腺素的干扰。在电位值为0.26 V(vs.SCE)处,肾上腺素在磷酸活化玻碳电极上有一灵敏的氧化峰。肾上腺素浓度cEP在1.0×10-6~1.2×10-5mol·L-1范围内与氧化峰电流ipa呈线性关系。检出限(3S/N)为3.0×10-7mol·L-1。方法应用于肾上腺素注射液的分析,测得肾上腺素含量与标示值相符。用标准加入法测得方法的回收率为99.7%。Abstract: Phosphate activated GCE was prepared by cyclic voltammetry, and the electrochemical behavior of epinephrine (EP) at this electrode in a phosphate buffer medium of pH 6.0 was studied. A cyclic voltammetric method for determination of trace amount of EP was proposed, by which the interference of ascorbic acid to the determination of EP was effectively eliminated. A sensitive oxidation peak of EP at 0.26 V (vs.SCE) was observed. Linear relationship between values of oxidation peak current (ipa) and concentration of EP was obtained in the range of 1.0×10-6-1.2×10-5mol·L-1, with detection limit (3S/N) of 3.0×10-7mol·L-1. This method was applied to the determination of EP in injections, giving results in consistency with the labelled values. Average recovery of the method found by standard addition method was 99.7%.
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