电化学分析法快速测定粮油食品中的总植物甾醇含量  

Rapid Detection of Total Phytosterol Content in Cereals, Oils, and Foodstuff by Electrochemical Analysis

作　　者：张媛媛[1] 吕双双[1] 李书国[1] 

机构地区：[1]河北科技大学生物科学与工程学院,河北石家庄050018

出　　处：《现代食品科技》2015年第5期297-302,共6页Modern Food Science and Technology

基　　金：国家自然科学基金面上项目(20876165);河北省科技支撑计划项目(14227121D);河北省教育厅科技项目(2009329)

摘　　要：本文研究了植物甾醇在裸玻碳电极上的电化学反应过程,建立了差分脉冲法快速测定粮油食品中的总植物甾醇含量的新方法。试验表明:通过快速循环伏安法测定植物甾醇在1.72 V处出现氧化峰,无还原峰,其电极反应过程是不可逆的;并且探索了电化学法测定植物甾醇的试验条件,结果显示:乙腈-异丙醇(9:1,V/V)为最佳有机溶剂,支持电解质是50 mmol/L高氯酸锂(Li Cl O4),脉冲幅度50 m V、电位增量为3 m V、脉冲宽度为0.05 s、脉冲间隔为0.3 s;在此条件下,以差分脉冲伏安法测定植物甾醇的线性范围是160~800μg/m L,检测限是8.8μg/m L(S/N=3),线性系数r=0.998。并用该法测定了玉米胚芽油脱臭馏出物中总植物甾醇含量,回收率为97.0~101.3%;结果表明,在非水溶剂中,电化学分析法测定植物甾醇是可行的,并且操作简便,样品无需前处理,测定结果精确。The electrochemical reaction process of plant sterols in a bare glassy carbon electrode was investigated to develop a new differential-pulse voltammetric method for rapid detection of phytosterols in cereals, oils, and other foodstuff. Cyclic voltammogram of phytosterols showed that the oxidation peak appeared at 1.72 V and no reduction peak was observed, which indicated that the electrode reaction process was irreversible. The electrochemical conditions were optimized for the detection of phytosterols. The results showed that the optimal conditions were: acetonitrile and 2-propanol(9:1,V/V) as organic solvent, 50 mmol/L Li Cl O4 as supporting electrolyte, pulse amplitude of 50 m V, potential increment of 3 m V, pulse width of 0.05 s, and pulse interval of 0.3 s. Under these optimized conditions, the calibration curves for determination of phytosterol demonstrated an excellent linear response within the range 160 to 800 μg/m L(r = 0.998), with the detection limit at 8.8 μg/m L(S/N = 3). The proposed method was successfully applied to the determination of phytosterol in corn germ oil deodorizer distillate and the recovery rate was 97.0% to 101.3%. The results indicate that the electrochemical analysis method is feasible for the detection of phytosterols in non-aqueous solvents, easy to perform, and does not require complicated pretreatment of samples.

关 键 词：植物甾醇 电化学分析 快速检测 粮油食品 

分 类 号：O657.1[理学—分析化学] TS207.3[理学—化学]