GC–MS Insights into Food Packaging Safety

Q. You have recently published a paper on the identification of volatile and semi-volatile compounds in food packaging using a gas chromatography–mass spectrometry (GC–MS) non-targeted method.¹ Could you talk us through the background and your findings?

A: This work was carried out within the framework of a research project focused on the study of the chemical safety of bioplastics for food contact. Replacing petroleum-based plastics with more sustainable solutions to reduce their negative environmental impact is an EU priority. In this context, bio-based and/or biodegradable plastics are being promoted as an alternative to conventional petroleum-based non-biodegradable plastics for use in food packaging. However, the critical aspect of chemical safety is often overlooked. The European framework Regulation 1935/2004 requires the safety of substances migrating from food contact materials (FCMs) into food.² The aim of this work was to apply non-targeted methodologies to investigate potential volatile and semi-volatile migrant compounds from bio-based and/or biodegradable food packaging materials. A wide variety of compounds were identified; bioplastics contain complex mixtures of substances, some of which have been classified as highly toxic according to Cramer's rules.

Q. You describe Purge and Trap (P&T)-GC–low-resolution (LR)MS and GC–high-resolution (HR)MS as complementary, but how much overlap existed between the two compound lists? Were any semi-volatile compounds detected by both methods?

A: Our research focuses on detecting any volatile and semi-volatile compounds present in bioplastics. P&T GC–MS is a highly suitable technique for detecting volatile substances, while GC–HRMS after extraction with an organic solvent is appropriate for detecting semi-volatile substances. Indeed, some substances can be detected by both techniques; however, both methodologies are complementary and allow us to obtain a complete characterization of the chemical composition of volatile and semi-volatile substances present in bio-based plastics.

Q. The 17 samples were acquired from Spanish retailers or industrial suppliers. How representative is this sample set of the broader European bioplastics market, and could regional manufacturing differences limit the generalisability of your findings?

A: This is a preliminary study in which different bioplastics with potential applications as food packaging materials, including bio-polyethylene, polyester-type polymers, PLA, were analyzed. The aim was to gain a preliminary insight into the chemical composition of these materials. Since differences in formulations and manufacturing processes between different suppliers result in different chromatographic profiles, a larger sampling would probably be more representative of the bioplastics that are on the market.

Q. You note that only nine of the 50 substances detected by HRMS appear on the EU positive list. Does this finding suggest that the current regulatory framework for bioplastics is inadequate?

A: In other previous studies carried out in the laboratory with conventional petroleum-based plastic food packaging materials, we also identified compounds present in the plastics that were not included in the EU positive list.^3,4

Q. How confident are you that another laboratory applying your optimized P&T and GC–HRMS workflows would arrive at a comparable compound list?

A: The analysis of food packaging materials, especially the identification of non-intentionally added substances (NIAS), presents significant challenges, partly due to the lack of standardized non-targeted screening methodologies. Studies reported in the literature have revealed discrepancies in the results obtained using non-targeted methods in different laboratories.⁵ These differences can be attributed to various factors, such as variations in analytical methods, the spectral libraries used, etc. In this specific case, I consider that if other laboratories apply the optimized workflows described here, using identical analytical conditions, analyzing an identical sample, and with very similar equipment, they should obtain a comparable compound list.

Q. Bio-based materials are often marketed as inherently safer alternatives to conventional plastics, yet your findings reveal a comparable or greater chemical complexity in some cases. Do you think the term "bio-based" misleads consumers and policymakers about chemical safety?

A: Indeed, our findings have revealed that bioplastics are chemically complex mixtures of substances comparable to conventional plastics. The fact that they are bio-based materials does not necessarily imply that they are safer alternatives to conventional materials. These materials are being promoted as a sustainable packaging solution. Numerous efforts are underway to develop environmentally friendly materials; however, the critical aspect of chemical safety often remains unaddressed. I consider it is necessary to evaluate the chemical safety of these materials particularly those for food contact applications to ensure consumer health protection.

Q. Several of the identified substances—particularly BHT degradation products and phthalate derivatives—are well-known contaminants from conventional plastics. Does their presence in bioplastics suggest cross-contamination during manufacturing, shared additive formulations, or something else entirely?

A: The main reason behind this research was to identify volatile and semi-volatile compounds present in bioplastics for food contact applications and in this way obtain valuable information about what substances have the potential to migrate into food. Quantification of the identified compounds was not performed in this study. Therefore, without quantification data, we cannot draw conclusions about the origin of the BHT degradation products and phthalate derivatives, that is we cannot determine if their presence is due to cross-contamination during manufacturing or if they were used as additives.

Q. Given the rapidly evolving bioplastics market, how frequently do you think non-targeted screening studies like this one need to be repeated to keep pace with new formulations entering the food contact sector?

A: The development of bioplastics is evolving very rapidly. With new formulations and manufacturing processes, studies like this one are necessary to fully understand the composition of the materials and thus to know the identity of the substances that could potentially migrate into food. This information is essential for assessing the safety of materials for food contact.

References

1. Vázquez-Loureiro, P.; Cariou, R.; Dervilly, G.; et al. Identification of Volatile and Semi-Volatile Components in Food Contact Bioplastics Based on GC–MS Non-Targeted Screening. J Chrom A 2025, 1762, 466377. DOI: 10.1016/j.chroma.2025.466377
2. European Union. (2004). Regulation (EC) No. 1935/2004 of the European Parliament and of the Council of 27 October 2004 on materials and articles intended to come into contact with food and repealing Directives 80/590/EEC and 89/109/EEC Official Journal of the European Union, L338, 4–17.
3. García Ibarra, V.; Rodríguez Bernaldo de Quirós, A.; Paseiro Losada, P.; Sendón, R. Non-Target Analysis of Intentionally and Non Intentionally Added Substances from Plastic Packaging Materials and their Migration into Food Simulants. Food Packag Shelf Life 2019, 21, 100325. DOI: 10.1016/j.fpsl.2019.100325
4. García Ibarra, V.; Rodríguez Bernaldo de Quirós, A.; Paseiro Losada, P.; Sendón, R. Identification of Intentionally and Non-Intentionally Added Substances in Plastic Packaging Materials and their Migration into Food Products. Anal Bioanal Chem 2018, 410, 3789–3803. DOI: 10.1007/s00216-018-1058-y
5. Koster, S.; Clement, F.; Wang, L.; et al. Interlaboratory Investigation of NIAS with Non-Targeted Methods: Need for Harmonisation. Food Addit Contam Part A 2025, 42 (8), 1034–1051. DOI: 10.1080/19440049.2025.2528794