In an article published on November 1, 2021, in the peer-reviewed journal Toxics, Pablo Miralles and co-authors from the Foundation for the Promotion of Health and Biomedical Research in the Valencian Region (FISABIO-Public Health), Valencia, Spain, reported on a fast and automatic method to analyze and identify intentionally added substances (IAS) but also non-intentionally added substances (NIAS) in plastic food contact materials (FCMs). The scientists developed an approach and performed a proof-of-concept using post-consumer recycled low density polyethylene (LDPE) film.
Since Miralles and co-authors aimed to develop a fast way to conduct an initial product screening, they performed extraction experiments with the organic solvent acetone at 40°C for one hour instead of using food simulants according to the European Commission Regulation (EU) No 10/2011. The LDPE extract was analyzed by gas chromatography coupled to high-resolution mass spectrometry (GC-Q-Orbitrap HRMS) followed by automated data processing and tentative identification of the acquired features. The criteria for a tentative identification were a NIST Library match score of >90%, an exact mass accuracy < 2ppm, and a retention index of absolute differences < 50 units.
Miralles et al. detected 374 annotated features in the recycled LDPE extract and tentatively identified 83 of them. These identified compounds included plastics additives, such as plasticizers, stabilizers, surfactants, emulsifiers, LDPE oligomers, as well as other “substances with a wide variety of industrial, chemical, and cosmetic applications.” According to the authors, 12 chemicals are included in the (EU) No 10/2011 regulation’s list of authorized substances. To validate their developed method, the scientists purchased commercially available analytical standards for 10 of the 83 tentatively identified substances and confirmed the identity of all 10 using these standards.
On the tentatively identified substances, the researchers also performed a risk assessment using the threshold of toxicological concern (TCC) approach. They found none of the chemicals to pose a safety risk but “complementary studies related with the toxicity of the unidentified substances and the potential mixture toxicity (cocktail effects) should be conducted in parallel using bioassays.” Previous studies have combined non-target chemical analysis with bioassay and reported toxicity of the chemicals mixtures that were contained in and migrating from plastics products (FPF reported and here).
The authors conclude that their developed method serves as a “fast and automatic approach that can be applied for the non-target analysis of unknown substances (IAS/NIAS) of different plastic FCM, showing its great utility and versatility.” The challenges regarding NIAS identification have previously been summarized in a review that also found the need to update regulations on NIAS in FCMs (FPF reported).
Miralles, P. (2021). “A Fast and Automated Strategy for the Identification and Risk Assessment of Unknown Substances (IAS/NIAS) in Plastic Food Contact Materials by GC-Q-Orbitrap HRMS: Recycled LDPE as a Proof-of-Concept.” Toxics. DOI: 10.3390/toxics9110283