Migration from can coatings: Part 3. Synthesis, identification and quantification of migrating epoxy-based substances below 1000 Da

• Published in: Food additives and contaminants Vol. 21; no. 4; pp. 390 - 405
• Main Authors: Schaefer, A., Simat, T. J.
• Format: Journal Article
• Language: English
• Published: London Taylor & Francis Group 01.04.2004; Taylor & Francis
• Subjects: Benzhydryl Compounds; Biological and medical sciences; can coatings; Chromatography, High Pressure Liquid - methods; Diffusion; Epoxy Compounds - analysis; Epoxy Compounds - chemistry; Epoxy Resins - analysis; Epoxy Resins - chemistry; epoxy-based substances; Food Analysis - methods; Food Contamination - analysis; Food engineering; Food industries; Food Packaging; Fundamental and applied biological sciences. Psychology; General aspects; Handling, storage, packaging, transport; high-performance liquid chromatography-electrospray ionization-mass selective detection (HPLC-ESI-MSD)/ultraviolet detection (UVD)/fluorescence detection (FLD); Humans; migration; Molecular Weight; size exclusion chromatography (SEC)-UVD; Spectrometry, Mass, Electrospray Ionization - methods; Migration; Size; Container content interaction; HPLC chromatography; Epoxy resin; Fluorescence; Identification; Analysis method; Ionization; Packaging; Control method; Detection; Food
• ISSN: 0265-203X; 1464-5122
• DOI: 10.1080/02652030310001657388

Bisphenol A-derived glycidyl ethers as well as its reaction products with other lacquer components can migrate into the packed food from epoxy-based can coatings. A sensitive and selective method is presented using high-performance liquid chromatography coupled with ultraviolet light, fluorescence and electrospray ionization-mass selective detection for the identification and quantification of all migrants with a bisphenol A backbone and a molecular weight below 1000 Da, an estimated boundary for the absorption in the gastrointestinal tract. The identification of migrants was confirmed by microreactions of technical bisphenol A diglycidyl ether with solvents and phenols, which provided the fragmentation pattern of the mass selective detection and relative retentions of 42 different bisphenol A-related substances. It was shown by calibration of different isolated and synthesized bisphenol A derivatives that the fluorescence response relies on the amount of bisphenol A moiety in the respective molecule. Therefore, all migrating bisphenol A-related substances below 1000 Da were determined as bisphenol A diglycidyl ether equivalents using a calibration (fluorescence detection) of the commercially available bisphenol A diglycidyl ether monomer. The limit of quantification was set at 5 μg bisphenol A diglycidyl ether equivalents kg −1 (or 0.8 μg dm −2 ). This method was validated for epoxy coatings (0.1 μg dm −2 limit of detection and 24 μg bisphenol A-related substances below 1000 Da dm −2 standard deviation, corresponding to 4.4% relative standard deviation). The quantification could be extended by combining the fluorescence response and structural information gained from the mass spectra, which provides more accurate results for each migrant. The calculation is based on the calibration of the bisphenol A chromophore content of the molecule. According to this method, the amount of migrating bisphenol A-related substances below 1000 Da in the acetonitrile extract (assuming a worst case) varied from about 0.4 to 0.7 mg dm −2 in the examined coatings. The determined amounts comply with about 50% of the total migrate below 1000 Da.