采用聚吡咯膜修饰电极检测植物油中亚油酸  

Detection of linoleic acid of vegetable oil using polypyrrole modified electrode

作　　者：张春娥[1] 薛文通[1] 王玮[1] 张惠[1] 

机构地区：[1]中国农业大学食品科学与营养工程学院,北京100083

出　　处：《食品科技》2011年第2期273-276,279,共5页Food Science and Technology

基　　金：国家自然基金项目(20876165);公益性行业科研专项(200910034)

摘　　要：采用已发明的用于植物油酸价检测的聚吡咯膜修饰电极测定植物油中亚油酸浓度。采用循环伏安法(CV)在乙腈溶液中聚合吡咯单体于铂电极表面制备化学修饰电极Ppy/ClO4-/Pt,用线性伏安法(LV)检测亚油酸浓度。通过修饰电极与裸电极表面上发生反应时的响应峰电流比较,可以发现修饰电极上的氧化还原反应转移步骤的动力学较快,且反应所需的电位较低,在较低浓度亚油酸存在下反应也可进行。结果表明:在浓度为9.6×10-6～1.28×10-3 mol/L之间,峰电流与亚油酸浓度呈现良好的线性关系,相关系数(R2)是0.9922,检出限为3.0×10-6 mol/L(S/N=3),灵敏度为0.495。并且将该化学修饰电极用于植物油(芝麻油、玉米油、花生油和大豆油)中游离脂肪酸浓度的检测。A Ppy-film electrode（poly pyrrole-TBAP-platinum） electrochemically deposited onto a platinum electrode has been developed for vegetable oil acid value determination.Using the Ppy/ClO4-/Pt（poly pyrrole-TBAP-platinum） modified electrode for measurement of linoleic acid concentration.Polypyrrole film was prepared using cyclic voltammetric（CV） method.Linear voltammetry was utilized for the measurement of linoleic acid by modified electrode.The result shown that the analytical curve was linear in the linoleic acid concentration from 9.6×10-6～1.28×10-3 mol/L with a limit of detection of 3.0×10-6 mol/L（S/N=3）.The correlation coefficient（R2） was 0.9922.The sensitivity was 0.495.The modified electrode was used for determination of linoleic acid in some real samples such as sesame oil,corn oil,peanut oil and soybean oil.

关 键 词：聚吡咯膜 化学修饰电极 循环伏安法 线性伏安扫描技术 亚油酸 

分 类 号：TS227[轻工技术与工程—粮食、油脂及植物蛋白工程]