用杯芳烃膜修饰碳纤维电极计时电流法测定过氧化氢

Chrono-amperometric Determination of Hydrogen Peroxide with Calixarene Modified Carbon Fiber Electrode

在含8．0×10^-4mol·L^-1杯芳烃的0．1mol·L^-1四丁基高氯酸铵溶液中，在-0．4～0．6V电位下，在碳纤维电极表面电沉积一层杯芳烃膜，制得杯芳烃膜修饰碳纤维电极。采用扫描电镜和交流阻抗法对电极表面的性能进行了表征，采用循环伏安法和计时电流法对其电化学性能进行研究。试验发现：过氧化氢在杯芳烃膜修饰碳纤维电极上出现一个明显氧化峰，氧化峰电位为0．6V，提出了用计时电流法测定过氧化氢的方法。在优化的试验条件下，氧化峰电流与过氧化氢的浓度在1．5×10^-5～3．8×10^-3mol·L^-1叫范围内呈线性关系，检出限（3S／N）为5．0×10^-6mol·L^-1。。修饰电极用于医用消毒水中过氧化氢的测定，所得结果与高锰酸钾滴定法测定值相一致，用标准加入法做回收率试验，所得结果在979，6～104％之间，测定值的相对标准偏差（n=10）为4％。

The modified electrode was prepared by electrodeposition of a film of calixarene on the surface of carbon fiber electrode at the potential range from -0. 4 to 0. 6 V （vs. SCE） from a solution of 8. 0× 10^-4mol · L^-1 calixarene dissolved in 0. 1 mol ·L^-1 tetrabutyl ammonium perchlorat〈 The surface property of the calixarene modified CFE were studied by scanning electron microscopy and AC impedance method, and its electrochemical property studied by cyclic voltammetry and chronoamperometry. It was found that the calixarene modified CFE showed a remarkable oxidation peak of hydrogen peroxide at the potential of 0. 6 V （vs. SCE）. Based on these findings, a selective method for determination of hydrogen peroxide by chronoamperometry was proposed. Under the optimized experimental conditions, linear relationship between values of oxidation peak current and concentration of hydrogen peroxide was obtained in the range of 1.5× 10^-5 -3. 8×10^-3mol · L^-1 , with its detection limit （3S/ N） of 5. 0×10^-6mol · L^-1. The proposed method was used in the determination of hydrogen peroxide in medical sterilizing water, the result obtained was conformed to that found by permanganate titration. The values of recovery found by standard addition method were in the range of 97%-104%, and value of RSD （n=10） found was 4%.