Identification and Analysis of the Migration of Primary Aromatic Amines from Flexible Food Packaging by High-performance Liquid Chromatography (HPLC)

Background and Objectives: Primary Aromatic Amines (PAAs) are contaminants that can migrate from food flexible packaging. The main origin of these compounds is polyurethane adhesives used in the laminating process of multilayer films. Residual aromatic di-isocyanates of the reaction of adhesive polymerization migrate into the food, and are hydrolyzed to PAAs by the moisture of food. 2,4- and 2,6-Toluene diamine (TDA) isomers or 4,4'-, 2,4'- and 2,2'-methylene diamine (MDA) may migrate from laminated multilayer films. In this study, the migration of TDAs and MDAs was identified and analyzed in 24 samples of multilayer film by validated High Performance Liquid Chromatography (HPLC). Materials and Methods: Migration test was applied by 3% acetic acid on a sample of laminated films. Migrants was pre-concentrated using solid phase extraction cartridges (SPE). PAA values were measured by HPLC-DAD instrument. Results: Of 24 laminated multilayer samples, 15 samples were acceptable and 10 samples had PAAs higher than 10 μg / kg. In the one sample of multilayer film, the total amount of 2,4-TDA and 2,6-TDA, and in the nine samples, the values of 2,4'-MDA and 2,2'-MDA were more than 10 μg/kg. Conclusion: We can detect and analyze the five primary aromatic amines from laminated multilayer films with HPLC method. Also we can check the safety of these films, defects of lamination process, the structure of adhesive base and its sanitary/insanitary status.