An integrated approach based on high resolution mass spectrometry for the determination of the leachable substances from cosmetic packaging

Plastic packaging for cosmetics is a source of human exposure to various chemicals potentially causing adverse health effects. Packaging materials contain both intentionally added substances (IAS), such as monomers, plasticizers, and antioxidants, as well as non-intentionally added substances (NIAS), which may be present as impurities in the raw materials used for the packaging production, oligomers, degradation products, or contaminants introduced during manufacturing processes. [1] These compounds can migrate to the cosmetic product, raising concerns about consumer health. Comprehensive identification of leachables is challenging due to the wide range of chemical classes and their varied physicochemical properties. Therefore, an integrated analytical approach based on different platforms is required for the untargeted analysis of such substances. [2] The aim of this research was to develop an untargeted, integrated workflow to evaluate compounds leached from cosmetic packaging, using high-resolution mass spectrometry (HRMS) in combination with different separation techniques—namely supercritical fluid chromatography (SFC) and ultra-high-performance liquid chromatography (UHPLC). HRMS analysis was performed using a Waters G2-Si Synapt Q-TOF using electrospray ionization in both positive and negative ion mode (ESI+ and ESI-). The samples of cosmetic packaging made of virgin and recycled polyethylene terephthalate (PET) were run in duplicate in data-independent acquisition mode. A 50% v/v ethanol solution was used as a food simulant: cosmetic packaging samples were filled with the food simulant and stored at 60 °C for 3 days. The samples were evaporated to dryness via vacuum evaporation concentration and redissolved in 1 mL methanol (up- concentration factor 100) and analyzed by both SFC-HRMS (normal phase) and UHPLC-HRMS (reverse phase). Data processing and alignment were performed using the MS-Dial software v 4.9, resulting in the extraction of 20284 and 7199 features from UHPLC-HRMS and SFC-HRMS, respectively. To reduce the high number of extracted features, filtering and data reduction strategies were applied, including a 5-fold change intensity threshold compared to the blank samples and library match. A suspect screening list of 6130 substances, including plastic monomers, additives and processing aids, was used to support compound identification. Identification confidence was enhanced through MS/MS spectral matching using the MassBank of North America (MoNA) and in-silico spectra generated via Competitive Fragmentation Modeling. [3] A total of 224 leachable compounds were annotated with confidence level 1 to 3 [4]: 147 by UHPLC-HRMS, 51 by SFC-HRMS, with 26 compounds annotated by both techniques. The annotated substances included plasticizers, dyes, intermediates, UV absorbers, flame retardants, antibacterial agents, flavouring agents, and antioxidants. These findings highlight the complementarity of UHPLC and SFC coupled with HRMS for profiling semi-volatile and non-volatile substances, thus strengthening the importance of an integrated approach for a comprehensive safety assessment of substances migrating from packaging materials. Further evaluation of semi-volatile components is currently in progress using in-situ derivatization followed by comprehensive 2D-Gas Chromatography (GC)-HRMS analysis. Finally, the complex data generated will be analyzed using multivariate statistical analysis techniques: unsupervised, supervised and data fusion approaches to improve the classification performance and identify the compounds capable of differentiating recycled and virgin PET.