Identification of recycled polyethylene and virgin polyethylene based on untargeted migrants

• Published in: Food packaging and shelf life 2021-12, Vol.30, p.100762, Article 100762
• Main Authors: Chen, Zhi-Feng, Lin, Qin-Bao, Su, Qi-Zhi, Zhong, Huai-Ning, Nerin, Cristina
• Format: Article
• Language: English
• Subjects: (Semi-)volatile organic compounds; GC-MS; Markers of recycled PE; Multivariate statistical analysis; Recycled polyethylene; Untargeted screening
• ISSN: 2214-2894; 2214-2894
• DOI: 10.1016/j.fpsl.2021.100762

With increasing attention to recycled polyethylene (PE), its safety as a food contact material has become non-negligible. In this study, we report an untargeted gas chromatography coupled to mass spectrometer (GC-MS) analysis combined with multivariate data analysis for discriminating recycled PE from virgin PE. 80 (semi-)volatile migrants were identified, including 10 hydrocarbons, 29 esters, 3 aldehydes, 9 alcohols, 2 ethers, 4 acids, 4 benzene derivatives, 4 ketones, 3 amides, 2 piperazine derivatives and 10 unknowns. The hydrocarbons in virgin samples showed a greater variety and abundance than those in recycled samples. Based on orthogonal partial least squares discriminant analysis (OPLS-DA) and non-parametric test, 38 markers were selected to establish a classification model to identify recycled and virgin PE. These markers mainly derived from additives, daily chemical products related and food related input pollutants, most of which were rich in recycled samples. Furthermore, in classification models, linear discrimination analysis (LDA) showed higher stability and predictability than soft independent modelling of class analogy (SIMCA). The average accuracy of training and prediction set reached 100% and 92%, respectively, in LDA model. The identification of recycled PE and virgin PE based on migration of untargeted substances is feasible. [Display omitted] •Untargeted GC-MS analysis combined with multivariate data analysis was used for discriminating recycled PE from virgin PE.•80 migrants can be divided into four main categories: hydrocarbon, esters, others and unknown.•38 markers include 8 daily chemical products and 2 food related contaminants, 9 additives and 19 unknown sources substances.•Identification of recycled and virgin PE based on untargeted migrants is feasible with the high accuracy of LDA.