2.5. Migration experiments
LDPE A, B, C and 0 films were stored in 3% acetic acid and 95%
ethanol by total immersion at 60 8C for 10 days. A 0.2%
surfactant solution was prepared by diluting the surfactant
solution NovaChem (mixture of surfactants, Postnova Analytics
GmbH, Germany) with ultrapure water (TKA Genpure,
Germany). Samples in 0.2% NovaChem were stored at 60 8C for
10 days. Additionally isooctane was chosen as second
alternative fat simulant under rapid extraction conditions at
40 8C for 24 h according to EN 1186-15. The migration
experiments were performed according to EN 13130-1 and
EN 1186-3. An area of 1 dm2 of the respective LDPE film was
stored in 100 ml Erlenmeyer flasks which were filled with
100 ml of the respective simulant, whereby the test films were
completely covered with the simulant. The samples were then
stored in a temperature controlled oven under the conditions
described above. At the end of the storage time the films were
removed from the simulant and the simulant was transferred
in several steps quantitatively to 15 ml centrifuge tubes. All
simulants were evaporated carefully under a gentle nitrogen
stream (at 40 8C) to dryness. The residues were then taken up
in 15 ml 3% nitric acid for ICP-MS measurements.