Halogen-containing microplastics such as polytetrafluoroethylene (PTFE) and poly(vinyl chloride) (PVC) are analytically relevant targets, yet their selective characterization by ICP-MS remains challenging, particularly for fluoropolymers due to the limited formation of F+ in conventional positive-ion mode. Here we introduce negative-ion single-event ICP-MS as a direct strategy for particle-resolved characterization of halogen-containing microplastics by monitoring F− …