Methods of analysis for 2-dodecylcyclobutanone and studies to support its role as a unique marker of food irradiation

Methods of analysis for 2-dodecylcyclobutanone (2-DCB) using gas chromatography with mass spectrometric detection (GC–MS), liquid chromatography with time-of-flight mass spectrometric detection (LC–TOF-MS) and LC with tandem MS (MS/MS) detection have been developed and optimised for maximum sensitivity to allow very low irradiation doses to be detected. The LC–MS/MS method, following derivatisation with 2,4-dinitrophenylhydrazine, was found to be the most sensitive technique and was used to determine the amount of 2-DCB formed from the model compounds palmitic acid, glyceryl tripalmitate and 1,3-dipalmitoyl-2-oleoylglycerol irradiated over a range of doses by two different irradiation sources (gamma and electron beam). The model compounds were also treated with a number of non-irradiation based processing techniques including heating in the presence and absence of oxygen, light, and redox active metal salts, in a conventional oven, microwave oven and pressure cooker. No 2-DCB was detected in any of the processed non-irradiated model compounds, reaffirming the hypothesis that 2-DCB is a unique radiolytic product that can be used as a marker of irradiation in foodstuffs.