Abstract: Recycled high density polyethylene (rHDPE) for food contact is one of the trends of the development of circular economy at present. However, the residual chemicals in RHDP for food contact may migrate to food, causing food safety risks. Twenty-three kinds of rHDPE samples for food contact provided by four enterprises were contacted with two representative food simulants (95% ethanol and 4% acetic acid) at 60℃ for 10 days as migration test conditions, and the substances migrated to the food simulants were detected by gas chromatography-quadrupole time-of-flight mass spectrometry (GC-QTOF-MS). The 161 substances screened out were classified according to their toxicity (from low to high, they were classified into I-IV grades), among which 59 substances were classified into III and IV grades, and their predicted octanol/water partition coefficient (XLogP) was greater than that of substances classified into I and II grades. Benzene and substituted derivatives account for the highest proportion in the screened substances. Phenylester plasticizers, degradation products of antioxidants and Polycyclic aromatic hydrocarbon (PAHs) need special attention. Using orthogonal partial least squares discriminant analysis (OPLS-DA), it is found that the migration amount of migrating substances in the samples at different stages is higher than that in the master batch samples. This study can provide a basis for the analysis and safety risk assessment of migrating substances in rHDPE for food contact.

Key words: recycled high density polyethylene (rHDPE), Migration, Gas chromatography tandem quadrupole time-of-flight mass spectrometry (GC-QTOF-MS), Orthogonal partial least squares discriminant analysis (OPLS-DA)