title: Accurate mass and nuclear magnetic resonance identification of bisphenolic can coating migrants and their interference with liquid chromatography/tandem mass spectrometric analysis of bisphenol A.
abstract: Two unknown compounds were previously determined to be potential interferences in liquid chromatography/tandem mass spectrometry (LC/MS/MS) analysis of bisphenol A (BPA) in canned infant formula. Both yielded two identical MS/MS transitions to BPA. The identities of the unknowns were investigated using accurate mass LC/MS, LC/MS/MS, and elemental formula and structures proposed. Exact identities were confirmed through purification or synthesis followed by (1)H and (13)C nuclear magnetic resonance (NMR) experiments, as well as comparisons of one unknown with commercial standards. Comparisons of negative ion electrospray ionization (ESI) MS/MS and accurate mass spectra suggested both unknowns to be structurally identical (to BPA and each other). Positive ion ESI spectra confirmed both were larger molecules, suggesting that in the negative mode they likely fragmented to the deprotonated BPA ion in the source [corrected]. Elemental composition of positive ion accurate mass spectra and NMR analysis concluded the unknowns were oxidized forms of the known epoxy can coating monomer, bisphenol A diglycidyl ether (BADGE). One of the unknowns, 2,2-[bis-4-(2,3-dihydroxypropoxy)phenyl]propane, commonly known as BADGE*2H(2)O, is widely reported as an epoxy-phenolic can coating migrant, but has not been suggested to interfere with the MS/MS analysis of BPA. The other unknown, 2-[4-(2,3-dihydroxypropoxy)phenyl]-2-[4'-hydroxyphenyl]propane, or the oxidized form of bisphenol A monoglycidyl ether (BAMGE*H(2)O), has not been previously reported in food or packaging.
authors.affiliation: US Food and Drug Administration, Center for Food Safety and Applied Nutrition, College Park, MD 20740, USA. Luke.Ackerman@fda.hhs.gov
authors.forename: Luke K
authors.initials: LK
authors.lastname: Ackerman
authors.forename: Gregory O
authors.initials: GO
authors.lastname: Noonan
authors.forename: Timothy H
authors.initials: TH
authors.lastname: Begley
authors.forename: Eugene P
authors.initials: EP
authors.lastname: Mazzola
mesh_terms: D001559:Benzhydryl Compounds; D002853:Chromatography, Liquid / Q000379:methods*; D018857:Food Packaging; D041943:Infant Formula / Q000737:chemistry; D019906:Nuclear Magnetic Resonance, Biomolecular; D010636:Phenols / Q000032:analysis / Q000737:chemistry*; D011407:Propane / Q000031:analogs & derivatives* / Q000032:analysis / Q000737:chemistry*; D053719:Tandem Mass Spectrometry / Q000379:methods*; D000098826:Bisphenol A Compounds
chemical_list: D001559:Benzhydryl Compounds; D010636:Phenols; D011407:Propane; C422413:2,2-bis(4-(2,3-dihydroxypropoxy)phenyl)propane; C006780:bisphenol A; D000098826:Bisphenol A Compounds