腌菜中亚硝酸盐的电化学检测

Electrochemical Detection of Nitrite in Pickled Vegetables

采用电沉积的方法将磷钨酸(H3PW12O40)沉积到预先用PDDA处理的玻碳电极上制得磷钨酸(H_3PW_(12)O_(40))修饰玻碳电极,通过循环伏安法分析该电极的电化学性质,研究其对亚硝酸盐的电化学作用,并测定腌菜中亚硝酸盐的含量。亚硝酸盐在6.67×10^(-6)~8.01×10^(-5) mol/L浓度范围内与电极还原电流呈线性关系,I(μA)=1.4508+0.0581c(μmol/L),R^2=0.9985(n=12)。最低检出限:1.41×10-6 mol/L。响应电流达到95%时所需时间小于4s。该电极具有制备简单、响应快、灵敏度高、检测限低等特点,用于检测亚硝酸盐,效果良好。

Phosphotungstic acid is fabricated on the glassy carbon electrode pretreated with PDDA by the electro-deposition method to obtain the POM modified electrode. Cyclic voltammetry technique is used to study the electrochemical properties of [PW12/PDDA-] modified electrode, the electrode has a significant catalytic activity on the reduction of nitrite. The electrode reduction current has a linear relationship, I（μA） -= 1. 4508 -F0. 0581c（Fmol/L）, R2 = 0. 9985 （n= 12） for nitrite in the range of 6.67 ×10^-6-8.01 ×10.5 mol/L, the detection limit is 1.41 × 10.6 mol/L. The preparation method is simple, with quick response, great sensitivity, low detection limit. The proposed method shows remarkable advantages and it should be applied in the practical aspects.