铋膜修饰玻碳电极用于线性扫描溶出伏安法测定铝箔中痕量镓

Linear Scanning Stripping Valtammetric Determination of Trace Amount of Gallium in Aluminum Foil Using Bismuth Film Modified Glassy Carbon Electrode

用电化学沉积法将铋离子修饰在玻碳电极上,应用此铋膜修饰玻碳电极测定镓时,将试液在pH 5.4的六次甲基四胺-盐酸缓冲溶液中在-1.30 V处预还原40 s,然后在-1.30^-0.50 V范围内扫描,使镓离子从修饰电极上溶出,实现了镓离子的溶出伏安法测定,在-1.01 V处可得镓离子的氧化峰电位,镓的质量浓度在0.002 8~0.21μg.L-1范围内与其峰电流值呈线性关系,方法的检出限(3S/N)为0.7 ng.L-1。方法用于测定铝箔中镓的含量,加标回收率在98.2%~103.8%之间。

Bismuth film modified glassy carbon electrode was prepared by electrochemical deposition of Bi^3＋-ion on glassy carbon electrode（GCE）.In the determination of Ga^3＋-ion,the test solution in（CH2）6N4-HCl buffer solution of pH 5.4 was prereduced for 40 s at-1.30 V,Ga^3＋-ion was then stripped from the electrode by differential pulse stripping voltammetery,scanning in the range from-1.30 to-0.50 V.Oxidation peak potential of Ga^3＋-ion was observed at-1.01 V,at where linear relationship between values of peak current of Ga^3＋-ion and its concentration was obtained in the range of 0.002 8-0.21 μg·L^-1.Detection limit（3S/N） of the method found was 0.7 ng·L^-1.The proposed method has been used in the determination of gallium in aluminum foil,giving values of recovery found by standard addition method in the range of 98.2%-103.8%.