Analysis and testing of bisphenol A, bisphenol A diglycidyl ether and their derivatives in canned dog foods

Abstract

An analytical method was developed for the simultaneous determination of bisphenol A (BPA), bisphenol A diglycidyl ether (BADGE) and their derivatives, BADGE·2H2O, BADGE·H2O, BADGE·HCl·H2O, BADGE·2HCl and BADGE·HCl, in canned animal food commodities using reversed-phase high-performance liquid chromatography (HPLC) with fluorescence detection. The samples were cleaned up using solid-phase extraction (SPE) with hydrophobic polystyrene–divinylbenzene (PS/DVB) copolymer sorbent. The performance characteristics confirmed that the method used was in accordance with the EU validation criteria. The recovery values ranged from 62 to 97%. The repeatability (CVr) and within-laboratory reproducibility (CVW) values ranged from 2.3 to 9.7% and from 2.8 to 10.8%, respectively, while the limit of detection (LOD) and the limit of quantification (LOQ) values ranged from 5 to 10 µg/kg and from 5 to 15 µg/kg, respectively. The method was successfully used to evaluate the levels of 7 bisphenols in 24 of the canned dog foods retailed on the Slovenian market. BADGE·2H2O was found in all the samples tested, with values ranging from 16 to 540 µg/kg, while BPA was found in 96% of the samples tested and ranged from <5 to 208 µg/kg. The contribution of BADGE·H2O and BADGE·HCl·H2O was minor, while no traces of BADGE, BADGE·2HCl or BADGE·HCl were detected. Epoxy phenolic coatings were identified in the cans tested by the Fourier transform infrared spectroscopy (FTIR) analysis. Given the temporary human tolerable daily intake (TDI) value of 4 µg/kg b.w./day recently laid down by the European Food Safety Authority (EFSA), these results, especially those for the BPA in canned dog foods, merit further attention and investigation.