Effects of Capacitive Coupling on Ion Remeasurement Using Quadrupolar Excitation in High-Resolution FTICR Spectrometry

摘要

Axial ejection is found to be the principal cause of the loss of ions during Fourier transform mass spectrometry remeasurement experiments. Ion remeasurement improves to near unit efficiency when an open-ended cylindrical analyzer cell is used with capacitive coupling of the excitation signal to the adjacent trapping plates. With capacitive coupling enabled for the entire experiment, 100% remeasurement efficiency is observed over a narrow mass range (10 Da) for 200 scans of ions of poly(ethylene glycol) formed by internal matrix assisted laser desorp-tion/ionization. Greater than 99.5% efficiency per re-measurement cycle has been achieved for wide mass range (1000 Da) remeasurement with capacitive coupling enabled. Further evidence for axial ejection during re-measurement comes from a comparison of remeasurement efficiencies obtained at different trapping potentials.