Condensed phase membrane introduction mass spectrometry: A new frontier for the real-time monitoring of hazardous chemical migration from food contact materials

In this study, the application framework of Condensed Phase Membrane Introduction Mass Spectrometry (CP-MIMS), a direct mass spectrometry technique, is extended for real-time monitoring of migration processes from food contact materials (FCMs) with a focus on Bisphenol A (BPA) as re-emerging contaminant. The whole instrumental system was properly designed to meet important requirements in terms of signal stability, low noise and ease of handling. A dedicated MATLAB APP was developed for semi-automated processing of instrumental output. A full factorial experimental design was applied to optimize five response variables by varying the acceptor phase flow-rate and composition, stirring, temperature, and membrane length. The CP-MIMS method was validated in tap water and food simulants, obtaining detection limits in the 0.8–6 µg/kg range. Considering the great advantage of real-time analysis of BPA migration from FCMs, not yet explored in literature, its high sample throughput and compliance with the green analytical chemistry principles, the CP-MIMS method has proven to be suitable for the determination of BPA below the specific migration limit established by the EU (0.05 mg/kg). The applicability of the method was demonstrated by performing migration tests on plastic articles, acquiring the migration profile of BPA over time for samples that showed detectable release of BPA. Excellent trueness was proved by comparison with a confirmatory liquid chromatography-high resolution mass spectrometry method. This study provides important insights into the role of CP-MIMS in scientific research to achieve valuable temporal resolution in the study of dynamic processes, such as the release of compounds from FCMs.