铜掺杂聚L-天冬氨酸修饰电极同时测定多巴胺和尿酸

用循环伏安法制备了铜掺杂聚L-天冬氨酸修饰玻碳电极，研究了多巴胺（DA）和尿酸（UA）在该修饰电极上的电化学行为，建立了同时测定DA和UA的新方法。在pH3．5的磷酸盐缓冲溶液中，扫描速率为120mV]s时，DA和UA在该电极上产生氧化还原峰，峰电位分别为Eps=0．429V、Epc=0．336V（DA）和Eps=0．617V（UA），DA和UA的氧化峰分开达0．188V。采用循环伏安法（CV法）和示差脉冲伏安法（DPVs法）同时测定DA和UA的线性范围分别为：DA：3．00×10^-6-4．00×100mol／L、4．00×10^-5～1．00×10^-4mlo/L（CV）、3．00×10^-7～3．00×10^-6mol／L、3．00×10^-6—1．00×10^-5mol／L（DPVs），UA：8．00×10^-6～5．00×10^-5mol／L、5．00×10^-5-2．00×10^-4mol／L（CV）、3．00×10^-7～5．00×10^-5mol／L、5．00×10^-5．2．00×10^-4mol／L（DPVs）；检出限分另U为8．0×10^-7mol／L、1．0×10^-6mol／L（CV）和3．0×10^-7mol/L、3．0×10^-7mol／L（DPVs）。用于人体尿液中DA和UA的同时测定,结果满意。

Simultaneous determination of dopamine and uric acid at copper doped poly(L-aspartic acid) modified electrode

The copper doped poly(L-aspartic acid) modified electrode was prepared using cyclic voltammetric method.The voltammetric behavior of dopamine(DA),uric acid(UA) and electrochemical method for simultaneous determination of DA and UA were studied at the copper doped poly(L-aspartic acid) modified electrode.In pH3.5 phosphate buffer solution,the modified electrode gave a pair of redox peaks at Epa=0.429 V,Epc=0.336 V for DA,one oxdition peak at Epa=0.617 V for UA at the scan rate of 120 mV/s.The separated oxidation peaks of DA and UA was divided 0.188 V.The linear response were obtained in the range of 3.00×10-6~4.00×10-5 mol/L、4.00×10-5~1.00×10-4 mol/L(CV) and 3.00×10-7~3.00×10-6 mol/L、3.00×10-6~1.00×10-5 mol/L(DPVs) for DA ;8.00×10-6~5.00×10-5 mol/L、5.00×10-5~2.00×10-4 mol/L(CV) and 3.00×10-7~5.00×10-5 mol/L、5.00×10-5~2.00×10-4 mol/L(DPVs) for UA,respectively.The detection limits of DA and UA were 8.0×10-7 mol/L,1.0×10-6 mol/L(CV) and 3.0×10-7 mol/L,3.0×10-7 mol/L(DPVs),respectively.The method was successfully applied to the simultaneous determination of DA and UA in human urine samples with satisfactory results.