活化玻碳电极直接测定牛奶中的亚硝酸盐  

Determination of nitrite in milk by activated glassy carbon electrode

作　　者：戴兴德 张爱菊[1] 张小林[1] 

机构地区：[1]平凉医学高等专科学校,甘肃平凉744000

出　　处：《中国卫生检验杂志》2015年第19期3266-3268,3271,共4页Chinese Journal of Health Laboratory Technology

摘　　要：目的研究亚硝酸根在活化玻碳电极上的电化学行为,建立线性扫描伏安法测定牛奶中亚硝酸盐的新方法。方法采用循环伏安法制备氢氧化钠活化玻碳电极,研究亚硝酸根在该电极上的电化学行为。结果在p H=7.0的氯化钾溶液中,亚硝酸根离子在活化玻碳电极上于0.82 V处产生灵敏的氧化峰。当NO-2的浓度(x)为1.0×10-5mol/L^1.0×10-2mol/L时,峰电流(y,m A)与浓度之间呈良好的线性关系,线性方程为y=0.328 5x+0.002 3,相关系数(r)为0.999 4,检出限为5.0×10-6mol/L。在电化学检测牛奶中亚硝酸盐含量时,不存在维生素C等还原性物质干扰,标准加入法测得方法的回收率为97%~98%。结论氢氧化钠活化玻碳电极具有良好的灵敏度、稳定性和选择性,可用于牛奶中亚硝酸盐的直接测定。Objective To study the electrochemical behavior of nitrite ion on electro- activated glassy carbon electrode（ EGCE） and establish a new method for the determination of nitrite in milk by linear scanning voltammetry. Methods An EGCE based on sodium hydroxide was prepared by cyclic voltammetry for studying the electrochemical behavior of the nitrite on this electrode. Results In the potassium chloride solution with p H = 7. 0,the nitrite ion on EGCE had a sensitive oxidation peak at 0. 82 V. When the concentration of NO-2（ x） was among 1. 0 × 10- 5mol / L- 1. 0 × 10- 2mol / L,the peak current（ y,m A） and the concentration showed a good linear relationship,the linear equation was y = 0. 328 5x ＋ 0. 002 3,and the correlation coefficient（ r） was 0. 999 4. The limit of detection was 5. 0 × 10- 6mol / L. And when to detect the concentration of NO2 in milk with electro- chemistry,there was no vitamin C and other reducing substances interference. The recovery rate was among97%- 98% by means of standard addition method. Conclusion EGCE has good sensitivity,stability and selectivity,which can be used for the direct determination of nitrite in milk.

关 键 词：亚硝酸根 活化玻碳电极 线性扫描伏安法 

分 类 号：O657.1[理学—分析化学]