基于对苯二酚在预阳极化的铂电极上的催化氧化和不可逆电对的双安培检测原理,提出了流动注射双安培法直接测定对苯二酚浓度的方法.使用一支经过恒电位预阳极化处理的双铂电极,在外加电位差为0.3 V时,通过偶合对苯二酚在一支电极上的氧化和氧化铂在另一支电极上的还原两个不可逆电极过程,构建了流动注射双安培检测体系.在pH 1.89的B-R缓冲溶液中,外加电位差为0.3 V时,对苯二酚氧化峰电流与其浓度在8.0×10-6~6.0×10-4mol·L-1范围内呈线性关系,检出限(3S/N)为4.0×10-7mol·L-1.连续测定1.0×10-5mol·L-1对苯二酚溶液,电流值的相对标准偏差为2.8%(n=10),以模拟水样为基底,加标回收率在98.6%~103.9%之间.

Based on the catalytic oxidation of p-dihydroxybenzene at pre-anodized platinum electrode,and on the principle of bi-amperometric detection of irreversible electrode reaction,a method of direct FI-biamperometric determination of p-dihydroxybenzene was proposed.In the bi-amperometric detection system,when a potential of 0.3 V was applied,irreversible catalytic oxidation of p-dihydroxybenzene was carried out at one of the Pt-electrode,and irreversible reduction of platinum oxide carried out at the other Pt-electrode.The proposed method was proved to be of high sensitivity and selectivity and was suitable to be used in automatic on-line analysis when cooperated with the flow-injection technique.The electrode reaction was performed in a B-R buffer of pH 1.89.Linear relationship between the oxidation peak currents and concentrations of p-dihydroxybenzen was obtained in the range of 8.0×10-6-6.0×10-4mol·L-1,with the detection limit (3S/N) of 4.0×10-7mol·L-1.Test for precision was performed at 1.0×10-5mol·L-1 p-dihydroxybenzen,the value of RSD (n=10) found was 2.8%.Using simulated water sample as matrix,recovery test was made by standard addition method,the values of recovery were found in the range of 98.6%-103.9%.