A new hybrid quadrupole-ion trap operational mode for miniature mass spectrometer

The increasing sophistication of miniature mass spectrometers necessitates significant analytical performance enhancements to meet the demands of on-site applications. Here, we address this need by integrating a hybrid quadrupole-ion trap (Q-IT) analyzer into a compact "Brick" mass spectrometer platform. We developed and characterized a novel hybrid Quadrupole-Ion Trap (hQ-IT) operational mode designed to improve duty cycle and mitigate space-charge effects. In this configuration, the quadrupole and ion trap share similar vacuum pressure and are driven by a synchronized RF circuit, simplifying the hardware. The quadrupole operates as a mass filter, selectively admitting ions into the trap. The key innovation of the hQ-IT mode is the parallelization of processes; by synchronizing the quadrupole's filtering with the ion trap's MS scan, ion injection and cooling occur concurrently with mass analysis. This approach abandons the discrete, multi-step cycle of conventional ion trap operation and consolidates the entire analytical workflow into a single, continuous scan. As a result, the hQ-IT mode demonstrated higher signal intensity while maintaining comparable mass resolution. Most notably, it achieved a 10-fold improvement in the limit of detection (LOD) compared to the conventional mode. This operational paradigm offers a clear path toward higher sensitivity and throughput in miniature systems and could readily be implemented to enhance the performance of laboratory-scale instruments.