Visualization of tocopherol acetate absorbed inside laminated films by a matrix-assisted laser desorption/ionization-imaging mass spectrometry

Abstract

The aim of this study was to visualize the sorption of tocopherol acetate as a penetrant into polymer films. A matrix-assisted laser desorption/ionization-imaging mass spectrometry (MALDI-IMS) technique was used to visualize the distribution of tocopherol acetate in films during the migration process. A phytic acid-aided MALDIIMS using 2',4',6'-trihydroxyacetophenone as a matrix allowed us to successfully visualize the absorbed tocopherol acetate in both ethylene-vinyl acetate copolymer (EVA) and low-density polyethylene (LDPE) films after 1 weekstorage of tocopherol acetate at 40°C. The IMS technique allowed us to also visualize the actual distribution of tocopherol acetate inside the EVA/barrier/EVA laminated films, in which tocopherol acetate sorption was blocked at the barrier layer.