Screening for chemicals in paper and board packaging for food use: chemometric approach and estimation of migration

An analytical survey of 20 paper and board (P&B) materials intended for food use was carried out with the aim to identify chemicals with a potential to migrate into foods. Representative materials covering a range of uses (primary and secondary packaging and article for take away foods) were obtained from distributors. A screening approach was applied by means of solvent extraction with subsequent analysis by gas chromatography/mass spectrometry. A large number of analytes were detected, and a chemometric approach was used to explore the data. Principal component analysis was used to identify and select some compounds as markers for sample classification. In the corrugated and printed packaging, it is worth emphasizing the presence of residual solvents, probably coming from printing inks, as well as hydrocarbons and aromatic compounds, mainly toluene and plasticizers linked also to the recycled pulp content such as diisobutyl phthalate or diisopropylnaphthalenes, whereas in the plastic-laminated samples, triacetin was identified as the prevailing compound. A literature search for safety data or legislative restrictions of the identified substances was performed. Additionally, the semi-quantification of the compounds in the packaging allowed a worst case estimation of food contamination by means of the infinite total migration model; occasionally, migration estimations overcame the specific migration limits. The chosen analytical methods coupled with a chemometric approach proved to be an effective way to describe the data; it may be concluded that only the simultaneous consideration of several chemicals with a multivariate approach allowed the investigated packaging materials to be distinguished.