钯掺杂聚精氨酸修饰电极同时测定5-羟基色氨酸和多巴胺

Preparation of Palladium Doped Poly(L-arginine)Modified Glassy Carbon Electrode and Simultaneous Determination of 5-Hydroxytryptophan and Dopamine

制备了钯掺杂聚L-精氨酸修饰玻碳电极（Pd-PA/GCE）,研究了5-羟基色氨酸（5-HTP）和多巴胺（DA）在该修饰电极上的电化学行为,建立了同时测定5-HTP和DA的电化学新方法。在pH=2.0的磷酸缓冲溶液中,扫描速率为160mV/s时,DA在该电极上产生一对氧化还原峰,峰电位分别为0.515V和0.464V;5-HTP在该电极上产生一个氧化峰,峰电位为0.643V,两者的氧化峰电位差达128mV。在最优条件下,同时测定5-HTP和DA的线性范围分别为：9.00×10-7~1.00×10-5 mol/L、1.00×10-5~4.00×10-5 mol/L（5-HTP）;7.00×10-7~1.00×10-5 mol/L、1.00×10-5~4.00×10-5 mol/L（DA）。检出限分别为7.0×10-7 mol/L和5.0×10-7 mol/L。方法可用于药剂中5-HTP和DA的测定。

A palladium doped poly（L-arginine）modified electrode was prepared by cyclic voltammetric method.The electrochemical behaviors of 5-hydroxytryptophan and dopamine on the palladium doped poly（L-arginine）modified electrode were studied.And a cyclic voltammetric method was developed for the simultaneous determination of 5-hydroxytryptophan and dopamine.In pH=2.0phosphate buffer solution,the modified electrode gave a pair of redox peaks at Epa=0.516 Vand Epc=0.464 Vfor dopamine and one oxidation peak at Epa=0.642 Vfor 5-hydroxytryptophan at the scan rate of 160 mV/s.Under the optimum conditions,the linear ranges for simultaneous determination of 5-hydroxytryptophan and dopamine were 9.00×10-7-1.00×10-5 mol/L and 1.00×10-5-4.00×10-5 mol/L for 5-hydroxytryptophan,and 7.00×10-7-1.00×10-5 mol/L and 1.00×10-5-4.00×10-5 mol/L for dopamine.The detection limits of 5-hydroxytryptophan and dopamine were 7.0×10-7 mol/L and 5.0×10-7 mol/L,respectively.The method was successfully applied to the determination of 5-hydroxytryptophan and dopamine in medicaments with satisfactory results.