竹炭修饰碳糊电极上多巴胺的电化学行为研究及分析应用

目的: 利用竹炭(Bamboo Charcoal,BC)与石墨、甲基硅油直接混合制备竹炭修饰电极(BC/CPE),研究多巴胺(Dopamine,DA)在BC/CPE上的电化学行为和动力学性质。 方法: 线性扫描伏安法(SLV)、循环伏安法(CV)、电位阶跃计时库仑法(CC)和计时电流法(CA)。 结果: DA在 BC/CPE上的峰电位差ΔE_p较在CPE上小102 mV,测得DA的的电荷转移系数α为0.58,扩散系数D为4.1×10^-5 cm²·s^-1,反应速率常数k_f为4.7×10^-3 cm·s^-1。氧化峰电流与DA浓度在1.00×10^-7~1.00×10^-4mol·L^-1范围内分两段呈线性响应,检出限为1.00×10^-7 mol·L^-1。 结论: BC/CPE对 DA的电化学氧化还原过程产生促进作用,该方法可用于多巴胺注射液中DA含量的测定。

Objective: Bamboo Charcoal modified carbon paste electrode(BC/CPE)was prepared.The electrochemical behaviors and kinetic properties of dopamine(DA) on BC/CPE were studied. Methods: Determine the content of DA with linear sweep voltammetry(LSV),cyclic voltammetry (CV),chronocoulometry(CC) and chronoampemmetry(CA). Results: The difference of peak potential at BC/CPE was less than 102 mV comparing with that at CPE.The charge transfer coefficient α,diffusion coefficient D and the apparent reaction rate constant k_f are 0.58,4.1×10^-5 cm²·s^-1 and 4.7×10^-3 cm·s^-1,respectively.The oxidation peak currents of DA versus its concentration have two linear regression equations in the concentration range of 1.00×10^-7-1.00×10^-4 mol·L^-1 with the detection limit of 1.00×10^-7 mol·L^-1. Conclusion: The modified electrode showed an excellent electrocatalytic activity for the DA electrochemical oxidation.The method can be applied in the determination of DA in injection samples with the satisfactory results.