聚谷氨酸修饰电极测定食品中的麦芽酚

Determination of maltol in food by cyclic voltammetry with the poly glutamic acid modified electrode

建立一种用聚谷氨酸修饰电极测定麦芽酚的新方法。制备了聚谷氨酸修饰电极,用循环伏安法研究了麦芽酚在聚谷氨酸修饰电极上的电化学行为。实验表明:聚谷氨酸修饰电极对麦芽酚的电化学氧化具有明显催化作用,与未修饰的玻碳电极相比,麦芽酚在聚谷氨酸修饰电极上的氧化峰电流明显增大;在p H8.0的磷酸氢二钠-柠檬酸缓冲溶液(sodium hydrogen phosphate-citric acid buffer solution,PBS)中,麦芽酚在聚谷氨酸修饰电极上呈现不可逆的氧化峰,氧化峰电流与麦芽酚浓度成正比,线性范围为2.40×10-6~6.61×10-4mol/L,检出限为8.0×10-7mol/L。用该种方法测定了面包、饮料、啤酒中的麦芽酚,回收率在98.8%~103.7%之间,结果满意。该方法灵敏、准确、实用,对食品中麦芽酚的测定具有实际意义和应用前景。

A novel vohammetry methodology was developed for determination of mahol using a poly glutamic acid modified electrode.The poly glutamic acid modified electrode was prepared by cyclic vohammetry.The eleetrochemical behavior of mahol on the poly glutamic acid modified electrode was studied.The experimental results showed that the poly glutamic acid modified electrode exhibited significant catalytic activity for the electro-oxidation of maltol,compared with the unmodified glassy carbon electrode,the oxidation peak current increased significantly at the poly glutamie acid modified electrode.In the sodium hydrogen phosphatecitric acid buffer solution （PBS） of pHS.0, an irreversible oxidation peak of matol was obtained by cyclic vohammetry,the oxidation peak current was proportional to the concentration of mahol in the range of 2.40 × 10-6 6.61 × 10-4 mol/L and the detection limit was 8.0 × 10-7 mol/LThe method was applied for the determination of mahol in food with satisfactory recoveries of 98.8%-103.7%.This method is sensitive,accurate and practical and it has practical significance and application prospects for the determination of matol in a series of food.