为快速检测食品中铝添加剂含量,建立了以8-羟基喹啉为探针电化学测定铝离子的新方法。利用电化学聚合方法制备了聚L-瓜氨酸修饰电极(poly L-citline modified electrode,PLCit/GCE),与玻碳电极(glass carbonelectrode,GCE)相比,8-羟基喹啉在修饰后的电极上的电流响应信号显著增大。由于8-羟基喹啉与铝离子易形成配位化合物,向8-羟基喹啉溶液中加入铝离子时,会使8-羟基喹啉在PCLit/GCE上氧化峰电流减小,产生负相关,因此用8-羟基喹啉为探针可实现对铝离子的检测。利用循环伏安法研究了8-羟基喹啉在PLCit/GCE上的电流与铝离子浓度的线性关系。优化实验条件后,以8-羟基喹啉为探针对Al³⁺进行测定,Al³⁺浓度在8.00×10^-8~1.00×10^-6 mol/L内时,与8-羟基喹啉氧化峰电流呈现良好的负相关线性关系,相关系数R=0.993 8,检出限为6.00×10^-8 mol/L。该方法用于蜂蜜中铝离子的测定,回收率为95.0%。

In order to determine rapidly the content of aluminum additives in food,a new electrochemical method is developed for the determination of aluminum ion with 8-hydroxyquinoline as probe.Poly-L-citrulline modified electrode (PLCit/GCE) is prepared via electrochemical polymerization.Compared with glassy carbon electrode,the current response signal of 8-hydroxyquinoline on the modified electrode increases significantly.Because the coordination compounds are easily formed between 8-hydroxyquinoline and aluminum ions,the oxidation peak current of 8-hydroxyquinoline on PCLit/GCE will decrease and result in a negative correlation when aluminum ions are added into 8-hydroxyquinoline solution.Therefore,8-hydroxyquinoline can be used as probe to detect aluminum ions.The linear relationship between the current of 8- hydroxyquinoline on poly-L-citrulline modified electrode and aluminum ion concentration is studied by means of cyclic voltammetry method.8-Hydroxyquinoline is used as a probe to detect Al³⁺ after experimental conditions are optimized.The concentration of Al³⁺ within 8.00×10^-8-1.00×10^-6 mol·L^-1 shows a good negative linear correlation with the oxidation peak current of 8-hydroxyquinoline on the modified electrode.The correlation coefficient is 0.993 8,and the detection limit is 6.00×10^-8 mol·L^-1.The recovery is 95.0% when this method is applied to detect aluminum ion in honey.

郭萌(2000-),女,本科生。