Identification of photodegradation products of Allura Red AC (E129) in a beverage by ultra high performance liquid chromatography-quadrupole-time-of-flight mass spectrometry.

The study deals with the identification of the degradation products formed by simulated sunlight photoirradiation in a beverage that contains Allura Red AC (E129) dye. An UHPLC-MS/MS method that makes use of high resolution quadrupole-time-of-flight mass spectrometer, was developed. For the identification of the degradation products the software tool Information Dependent Acquisition (IDA) was used to automatically obtain information about the high resolution MS and MS/MS spectra of the species present. Accurate mass data were essential for the identification of the appropriate elemental composition: the elucidation of unknown chemical structures was obtained by using powerful software to mine the recorded chromatogram. The identified degradation products are formed from side-reactions and/or from the interactions taking place among the dye and other ingredients present in the beverage (i.e. ascorbic acid, citric acid, sucrose, aromas, strawberry juice and extract of chamomile flowers). The presence of aromatic amine or amide groups in the chemical structures of the degradation products suggests the potential hazard for the consumer health.