Data-Driven Collision Cross Section Library for Structural Analysis and Identification of Expanded Polystyrene Buoy Photodegradation Products in Aquaculture

초록

The environmental impact of photodegradation products from Expanded Polystyrene (EPS) aquaculture buoys poses a growing ecological concern. Structural characterization of these degradation products, particularly isomeric intermediates, has been limited. This study addresses these challenges by developing a compound-specific collision cross-section (CCS) database using cyclic ion mobility-mass spectrometry (cIM-MS) combined with in silico CCS calculations. A total of 49 photodegradation products were identified. Calculated CCS values showed discrepancies of less than 5% when compared with experimental measurements and were further validated using six reference standards. Despite improvements in resolution through multipass cIM-MS experiments, isomers with CCS differences less than 1 & Aring;2 remained unresolved. To overcome this, Gibbs free energy calculations were conducted, providing additional identification confidence in distinguishing structurally similar isomers. The resulting CCS database enhances the accuracy of compound identification in environmental monitoring and supports ecological risk assessments associated with EPS degradation. This work highlights the value of integrating experimental ion mobility data with computational modeling to resolve structural ambiguities in complex environmental mixtures.

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