Studies On Determination And Reaction With Amino Acids Of Bisphenol Diglycidyl Ethers In Canned Food

Bisphenol diglycidyl ethers are found to migrate from can coatings into foods,and react with food components,leading to health problems.Thus,it is important to develop methods for determination of bisphenol diglycidyl ethers in canned food and study the reaction of bisphenol diglycidyl ethers with food components.The objectives of this work were to develop a high-performance liquid chromatography(HPLC)with fluorescence detection(FLD)method for simultaneous determination of bisphenol A diglycidyl ether(BADGE)and its derivatives in canned food,and to investigate the reaction rules and reaction mechanisms of BADGE with amino acids,as well as identify the reaction products.The main results are listed as follows:1.A HPLC-FLD method was developed for simultaneous determination of BADGE,BADGE ·H2O,BADGE 2H20,BADGE HCl,BADGE-2HC1,BADGE· H2O· HCl in canned food.The method was developed using spiked food matrixes.Separation conditions were optimized using the modeling software DryLab(?).Good separation in 5 min was obtained using a core-shell particle column.The linear regression coefficients>0.9995.The limit of detection(LOD)varied from 1.03 to 1.57 ng/g and the limit of quantification(LOQ)were from 3.43 to 5.24 ng/g.The analytical recoveries ranged from 91.65%to 100.76%.The RSD for repeatability were less than 7.02%.The developed analytical method in our study is rapid,low-cost,strong interference-resistant,and suitable for the determination of BADGE and its derivatives in canned food.2.The response surface methodology(RSM)was applied to investigate the reaction rules of BADGE with methionine(Met),cysteine(Cys),and histidine(His)in model systems.The regression models for each reaction system were established.The reaction yields of all systems increased significantly with prolonged time,elevated temperature,and higher BADGE concentration.The reaction yields of BADGE with Met and His decreased to minimum values,and then increased with higher pH value.Under alkaline and neutral conditions,the reaction of BADGE with Cys was very fast,while under acidic conditions the reaction was much slower.Moreover,interaction between factors showed significant effects on the reaction yields.3.Some reaction products of BADGE with methionine,cysteine,and histidine were tentatively identified with HPLC coupled to electrospray ionization mass spectrometry(ESI-MS),including BADGE · 2Met,BADGE · H2O·Met,BADGE SCH3 Met,BADGE H20 SCH3,BADGE 2SCH3,BADGE H2O·Cys,BADGE·2Cys,BADGE·2His.The reaction mechanisms of BADGE with methionine,cysteine,and histidine were discussed.The electrophilic epoxy groups of BADGE are likely to react with nucleophilic species of amino acids.The reaction products of BADGE with amino acids were different under acidic and basic conditions.This is due to the following:(1)The nucleophile attack different carbon atom under acidic and basic conditions;(2)The intermediate product of BADGE and Met under acidic conditions is unstable;(3)The nucleophilic properties of sulfhydryl group of Cys under acidic and basic conditions are significantly different.The results of this work provide theory basis and guidance for improving the safety of canned products and perfecting regulations at home and abroad.