Study On Determination Of Vitamin E By Electrochemiluminescence Sensing

Tocopherol（TP）is a dietary supplement required by the human body,and its content is often accompanied by changes in human body function or health status.The RAD and the FNB had stipulated the daily intake of TP for people,and even for different age groups,the amount is different.Therefore,quantifying TP is crucial.At this stage,the analytical methods of TP are relatively unitary and mainly focus on traditional chromatography,which is complicated,costly and time-consuming.With the continuous improvement of people’s attention to food nutrition and the development of the healthy food industry,how to quickly detect and evaluate the nutritional components of food is an urgent problem that needs to be solved.The content of TP in food has an important impact on the nutritional quality of food.The establishment of an efficient and rapid detection method for TP in food can provide advanced technical means for the rapid evaluation of food nutritional quality.In this paper,the rapid detection of TP by sensing is the research object,and two sets of electrochemiluminescence（ECL）detection methods for the detection of TP have been established.Firstly,a rapid detection ECL sensing based on LDH was constructed.By grafting Ti₃C₂T_x-QDs on the surface of LDH-IL composite nanomaterials,taking advantage of Ti₃C₂T_x in structure and composition and the dual signal amplification of LDH-IL,this method has a selective quenching effect on TP.After the optimal selection of parameters,the linear response equation F₀-F=476.4028 lg C_TP+4814.4150（R²=0.996）with a detection limit of 6.34×10^-10mol·L^-1 was obtained in the range of TP concentration from 5×10^-9to 1×10^-3 mol·L^-1.The recoveries of standard additions in milk powder,eggs,rice and flour were 84.56%to 102.99%,which was consistent with the results of HPLC,confirming the practical performance of this system for the detection and identification of TP.Secondly,a MIECLS sensor system based on BP was constructed.By combining the electropolymerization molecular imprinting technique and immobilizing QDs on the surface of BP-IL,the active BP can be passivated and stabilized by the IL,whereas BP,as the underlying modification material made by IL can adhere to the electrode surface firmly.This method produces a specific quenching of TP under the dual effects of the signal amplification effect of BP-IL on QDs and the TP-specific spatial structure of MIPs.Finally,the linear regression equation of TP detection as the concentration of 1×10^-10～1×10^-4mol·L^-1 was F₀-F/F₀=0.0734 lg C_TP+1.0999（R²=0.998）,with detection limit of6.19×10^-11mol·L^-1.At the same time,the recovery rates in milk powder,eggs,rice and flour were 85.43%～100.65%,which was consistent with the verification results of HPLC,and the practicability of the sensor for the detection and identification of TP had been confirmed.