杯[4]芳烃化学修饰玻碳电极对多巴胺的测定

Determination of Dopamine with Calix[4]arene Modified Glassy Carbon Electrode

研究了多巴胺在杯[4]芳烃化学修饰玻碳电极上的电化学行为，建立了一种直接测定多巴胺的电化学方法。在0．1mol·L^-1KH2PO4一Na2HPO4（pH7．4）底液中，开路搅拌富集300s后，多巴胺在＋0．158V（vs SEE）处产生1个灵敏的准可逆氧化峰，电极反应主要受扩散控制，氧化峰电流，。与多巴胺浓度在1．0×10^-65．0×10^-4mol·L^-1范围内呈现良好的线性关系，检出限达7．0×10^-7mol·L^-1。同一支电极连续10次测定1．0×10^-4mol·L^-1的多巴胺溶液，相对标准偏差为2．6％。该法用于盐酸多巴胺针剂中多巴胺含量的测定，结果令人满意。

The electrochemical behavior of dopamine （ DA ） was studied at calix [ 4 ] arene modified glassy carbon electrode （CMGCE）. A sensitive semi-reversible oxidation peak was observed at ＋0. 158 V（vs SCE）in 0. 1 mol.L^-1 pH 7.4 phosphate buffer solution after 300 s accumulation with stirring under the condition of open circuit. The experimental results showed that the charge transfer process in the modified electrode was controlled by diffusion. The peak current increased linearly with the concentration of DA in the range of 1.0 × 10^-6 -5.0 × 10^-4 mol.L^-1 with a correlation coefficient of 0. 999 3. The determination limit was 7.0 × 10^-7 mol.L^-1. The relative standard deviation obtained by ten successive determination of 1.0 × 10^-4 mol.L^-1 DA was 2.6% . The electrode showed better repeatability and stability injection sample with satisfactory result.