Breastmilk storage containers made from plastic materials are commonly used to store excess breastmilk samples for infant feeding. While these plastic containers are often analysed to ensure they are safe from known harmful chemicals such as BPA, there is very little information on the occurrence of other potentially harmful constituents such as unexpected chemical substances in the plastic material. This study aimed to identify major chemical migrants from breastmilk plastic containers and propose chemical structures of these compounds. It also evaluated migration profile differences between mono and multilayer plastic products and samples defrosted under different temperatures.
Migration studies were carried out in food simulant and cow´s milk according to the European Regulation. Simulant samples were diluted with water while cow milk samples were extracted using a modified QuEChERS method. Samples were analysed using liquid chromatography coupled with high-resolution mass spectrometry with a data-independent acquisition method and a non-targeted workflow. The identification of major migrants was facilitated by multivariate analysis and confirmed using an in-house MS2 library of potential chemical structures.
Results showed the identification of nine compounds, five of these were matched in MS2 library. The majority of the identified migrants were cyclic oligomers that can originate from adhesives used on plastic material. Migrant compounds were detected in both mono and multilayer plastic containers, but multilayer samples comprised of more chemical migrants of higher peak intensities. Similar trends were observed when comparing room-temperature and warm water-defrosted samples.