Positive ion mass spectrometry enables simplified radiocarbon analysis

Radiocarbon ( 14 C) analysis underpins research and regulation across archaeology, Earth system science, the life sciences, and bio-content verification, yet remains constrained by reliance on accelerator mass spectrometry (AMS). Although AMS delivers the sensitivity required to measure natural 14 C abundances, it is built around a single technological paradigm — negative-ion source coupled to high-energy acceleration — that limits automation, throughput, and integration with mainstream analytical workflows. Here we introduce positive-ion mass spectrometry (PIMS), a fundamentally different paradigm for radiocarbon analysis. Instead of using negative-ion production in the source and particle accelerators to suppress isobaric interferences, PIMS achieves simultaneous atomic and molecular interference removal through controlled ion–gas interactions in a collision cell. This decouples interference suppression from ion generation and enables radiocarbon measurement using compact, plasma-based, gas-accepting ion sources operating directly on CO 2 , delivering AMS-level performance within automated gas-phase workflows.