HPLC method for determining ethylenediamine migration from epoxy-amine food packaging coatings into EU food simulants

A simple, rapid, sensitive and inexpensive method has been developed for the determination of ethylenediamine (EDA) in European Union food simulants. The method involves precolumn derivatization with ortho-phthaldehyde (OPA) and 2-mercaptoethanol (ME) to obtain a fluorescent derivative. Liquid chromatographic (HPLC) elution was achieved with methanol-ultrapure water (65:35) as mobile phase with a Waters Spherisorb 5 microm ODS 2 column. Fluorescence detection (FD) was performed at 330 nm (excitation wavelength) and 450 nm (emission). Total chromatographic analysis time was < 10 min. The proposed method was validated by checking linearity, detection and quantification limits, and precision. Relative recovery rates were of about 100% because samples and standard-spiked blanks were processed in the same way. Method precision (RSD < 6%) was satisfactory and the quantification limit (0.25 mg x (-1)) indicated that specific migration limit for EDA in EU food simulants (12 mg x kg(-1)) can be easily controlled. When the validated method was applied to epoxy-amine formulations used for can coatings under different curing conditions, EDA migration was < 1.4 mg x l(-1).