溶胶-凝胶膜修饰碘电极测定食物中Vc含量  

Determination of vitamin C in food with sol-gel film modified iodide electrode

作　　者：杜宝中[1] 张东霞[1] 李鹏飞[1] 吉妮妮[1] 胡池芳[1] 

机构地区：[1]西安理工大学应用化学系,陕西西安710054

出　　处：《化学传感器》2007年第1期54-57,共4页Chemical Sensors

摘　　要：用溶胶-凝胶包埋硝酸银制备了碘电极,并研究了其性能、测定条件及干扰物质的影响。提出了用碘电极指示Vc与I2定量反应释放的I-的浓度来测定Vc含量的方法。该电极在0.1mol/LKNO3,pH=2.0～6.0溶液中,对Vc浓度在10-1～10-5mol/L范围内呈Nernst响应,响应斜率为59.8mV/pVc,检测下限为7.9×10-6mol/L,回收率为95.4%～103.1%,可广泛用于医药、食品等行业对Vc含量的测定。In this paper, a new iodide electrode has been prepared by embedding AgNO3 withe sol - gel technology. The performances of the electrode, their determining conditions and the effects of other substances have also been studied in detail. The electrode can idicate the concentration of I^-, which generated by Vc react with I2 quantitatively. So, Vc in food can be determined by iodine electrode. The electrode in mixed solution of 0. 1 mol/L KNO3 with pH2. 0 - pH6. 0 showed Nernst response to ascorbic acid with a slope of 59. 8 mV/pVc, and a linear range of 10^-1 - 10^-5 mol/L. The detection limit is 7.9 × 10^-6 mol/L. The recovery is 95.4% - 103.1%. The electrode can be used for the determination of Vc content in medicament, food etc.

关 键 词：溶胶-凝胶 碘离子选择电极 维生素C 

分 类 号：TS207.3[轻工技术与工程—食品科学]