Migration and characterisation of nanosilver from food containers by AF4-ICP-MS

In this work, silver migration from commercial food containers was evaluated according to European Regulation 10/2011. Several experimental parameters affected silver release: food simulant, temperature, exposition time and sampled bag area. Results demonstrated a significant silver nanoparticle (AgNP) migration into aqueous and acidic simulants. The amount of silver migrated increased with storage time and temperature although, in general, silver showed a low tendency to migrate into food simulants (17 ng/g). However, the food simulant did not seem to be a really outstanding variable for long term storage. AF(4)-ICP MS was used to confirm the presence of AgNPs in the simulants. The low limit of detection achieved (0.4 mu g L-1) allowed the identification of AgNPs and their size characterisation (40-60 nm). Finally, scanning electron microscopy/energy-dispersive X-ray analysis suggested a possible transformation of the AgNPs detected in the extracts, due to association with other ligands, such as chlorine and sulphur, present in the original containers. (C) 2014 Elsevier Ltd. All rights reserved.