Performance Evaluation of a Hybrid Linear Ion Trap/Orbitrap Mass Spectrometer

TLDR

The paper describes the design and performance of a novel hybrid linear ion trap/orbitrap mass spectrometer. The instrument couples a linear ion trap to an orbitrap via an rf‑only quadrupole, injects pulsed ion beams into a rapidly changing electric field, traps them at high kinetic energies, detects image current after field stabilization, and uses Fourier transformation of the transient to achieve wide mass‑range detection with high resolving power, mass accuracy, and dynamic range. The hybrid instrument operates in LC/MS mode at 1 spectrum/s with a nominal resolving power of 60,000, mass accuracy within 2 ppm (internal) or 5 ppm (external), a maximum resolving power exceeding 100,000, and real‑time acquisition of up to three high‑mass‑accuracy MS/MS spectra per second.

Abstract

Design and performance of a novel hybrid mass spectrometer is described. It couples a linear ion trap mass spectrometer to an orbitrap mass analyzer via an rf-only trapping quadrupole with a curved axis. The latter injects pulsed ion beams into a rapidly changing electric field in the orbitrap wherein they are trapped at high kinetic energies around an inner electrode. Image current detection is subsequently performed after a stable electrostatic field is achieved. Fourier transformation of the acquired transient allows wide mass range detection with high resolving power, mass accuracy, and dynamic range. The entire instrument operates in LC/MS mode (1 spectrum/s) with nominal mass resolving power of 60,000 and uses automatic gain control to provide high-accuracy mass measurements, within 2 ppm using internal standards and within 5 ppm with external calibration. The maximum resolving power exceeds 100,000 (fwhm). Rapid, automated data-dependent capabilities enable real-time acquisition of up to three high-mass accuracy MS/MS spectra per second.