流动注射双安培法测定尿囊素的研究

Flow Injection Biamperometric Determination of Allantoin

基于尿囊素的不可逆氧化和氧化铂的不可逆还原构成的双安培检测体系,建立了测定尿囊素的电化学新方法。在外加电压为0.10V时,通过偶合尿囊素在一支电极上的氧化及氧化铂在另一支电极上的还原两个不可逆电极过程,构成流动注射双安培检测新体系。在pH=2.2的邻苯二甲酸氢钾-盐酸缓冲溶液中,测得尿囊素的氧化电流与其浓度在1.0×10-6～1.0×10-3 mol/L范围内呈良好的线性关系(r=0.9993),检出限为5.0×10-7 mol/L。连续40次测定1.0×10-5 mol/L的尿囊素,其峰电流相对标准偏差(RSD)为3.33%。该方法用于硫酸锌尿囊素眼药水中尿囊素含量的测定,结果令人满意。

A simple,rapid,and accurate flow-injection electrochemical method for on-line determination of Allantoin was established.This method was based on the electrocatalytic oxidation of Allantoin at the platinum electrode and the flow injection biamperometry principle of the irreversible couple system.By coupling the oxidation of Allantoin at a Pt electrode and the reduction of PtO at the other electrode,under the applied potential difference of 0.10 V,the linearity between current and Allantoin concentration was obtained over the range of 1.0×10-6~1.0×10-3 mol/L（r=0.9993,n=7） with the detection limit of 5.0×10-7 mol/L.The relative standard derivation of 3.33% was obtained for 40 successive determination of 1.0×10-5 mol/L Allantoin.The method was used for the determination of Allantoin in Zine Sulfate and Allantion Eye Drops with satisfactory results.