Chemical Fingerprinting of Synthetic Polymers via Direct Insertion Probe Mass Spectrometry

We report on the chemical fingerprinting of synthetic polymers using direct insertion probe mass spectrometry (DIP-MS), an analytical approach requiring only minimal sample preparation. A total of 38 different polymers were analyzed using temperature-programmed DIP-MS with atmospheric pressure chemical ionization (APCI) to establish a comprehensive spectral library. The studied polymers included homo- and copolymers from various classes, such as polyolefins, polyethers, polyesters, polyamides, styrenics, thermoplastic elastomers, and fluoropolymers. DIP-APCI-MS provided detailed structural information, enabling reliable identification of nearly all polymers based on their characteristic thermal decomposition patterns. Moreover, the utilization of temperature-programmed approach allowed monitoring of sample degradation as a function of temperature, further aiding polymer identification. Overall, temperature-programmed DIP-APCI-MS proved to be a robust and efficient method for the chemical fingerprinting of synthetic polymers, with potential applications in areas such as microplastic analysis and plastic recycling.