DETERMINATION OF 2-ALKYLCYCLOBUTANONE USING FLUORESCENT LABELING

2-Alkylcyclobutanones are formed under the influence of ionising radia tion from triglycerides. The determination of cyclobutanones could be a powerful means of identifying irradiated foods, not only from a lega l viewpoint but also in food quality control. In this paper 2-dodecylc yclobutanone was used as a model substance, synthesised by means of th e key substance 1-bromo-1-ethoxycyclopropane. The determination was ca rried out by labelling the cyclic ketone with fluorescent dyes and sub sequent HPLC separation. 1-Pyrenebutyrylhydrazide and 7-diethylamino-3 -carbonylazide were used as labelling reagents. Dodecylcyclobutanone w as sensitively determined in fat matrices. Labelling with 1-pyrenebuty rylhydrazide was unsuccessful because of its low reactivity. Medium- a nd short-chain aldehydes and ketones were easily labelled. After reduc tion to the corresponding alcohol, dodecylcyclobutanone, as well as al dehydes and ketones, were successfully labelled with 7-diethylamino-3- carbonylazide. Separation was carried out with good results on RP-18 r eversed phases using methanol water mixtures as mobile phases. The det ection limit of dodecylcyclobutanone is about 5 ng.