Abstract: A total of 21 kinds of recycled high-density polyethylene (rHDPE) in contact with food were selected from three companies. Migration experiments were performed by contacting these samples with two representative food simulants (95% ethanol and 4% acetic acid) at 60 ℃ for 10 days. The migration of substances to food simulants was detected by gas chromatography quadrupole time-of-flight-mass spectrometry (GC-QTOF-MS). Altogether 161 substances were selected and classified into four grades in decreasing order of toxicity (I–IV), among which 59 substances belonged to grades III and IV, and their predicted octanol/water partition coefficient (XLogP) was greater than that of the substances belonging to grades I and II. Benzene and substituted derivatives accounted for the highest proportion of all selected substances. Special attention should be paid to phenylester plasticizers, degradation products of antioxidants and polycyclic aromatic hydrocarbon (PAHs). Changes in the migration of substances from the samples were analyzed using orthogonal partial least squares-discriminant analysis (OPLS-DA), and it was found that the migration of substances from the final products was elevated compared with that from the masterbatch samples. This study can provide a theoretical basis for the analysis and safety risk assessment of migrating substances in rHDPE in contact with food.

Key words: recycled high-density polyethylene; migration; gas chromatography quadrupole time-of-flight-mass spectrometry; orthogonal partial least squares-discriminant analysis