用碳黑微电极伏安法测定多巴胺

VOLTAMMETRIC DETERMINATION OF DOPAMINE WITH CARBON BLACK MICRO ELECTRODE

摘要: 研究了多巴胺(DA)在碳黑微电极上的电化学行为,试验结果表明,在pH 4.5(pH 3.8-5.2)的磷酸盐缓冲介质(PBS)中,多巴胺在伏安图0.21 V处的二阶导数峰高与其浓度在6×10-6-2×10-5mol·L-1之间保持线性关系,其检出限(3σ)为1×10-6mol·L-1；将此方法应用于多巴胺针剂试样的分析,测定结果的RSD值(n=5)均小于2.4%,用标准加入法做回收率试验,结果在96%-102%之间.此方法所测得结果与碘量法测得的结果之间无显著差异.

Abstract: The electrochemical behaviors of dopamine (DA) at the carbon black micro-electrode was studied.It was shown by the experimental results that in a phosphate buffer medium of pH 4.5 (pH 3.8-5.2),linear relationship between the peak current and the concentration of DA in the range of 6.0×10-6-2.0×10-5mol·L-1 was obtained,with a detection limit (3σ) of 1.0×10-6mol·L-1 of DA.The proposed method has been applied to the determination of DA in samples of dopamine injection,giving values of RSD (n=5) less than 2.4% and recoveries in the range of 96%-102%.The results obtained by this method were found to be in conformity with those obtained by iodometry.