Efficient Ion Remeasurement Using Broadband Quadrupolar Excitation FTICR Mass Spectrometry

Area of Science:

• Analytical Chemistry
• Physical Chemistry
• Spectroscopy

Background:

• Fourier Transform Ion Cyclotron Resonance (FTICR) mass spectrometry is a powerful analytical technique.
• Efficient ion manipulation and remeasurement are crucial for advanced FTICR experiments.
• Optimizing quadrupolar excitation is key to improving ion axialization and detection in FTICR.

Purpose of the Study:

• To investigate and compare different quadrupolar excitation methods for efficient ion remeasurement in FTICR mass spectrometry.
• To determine the factors influencing ion loss during remeasurement experiments.
• To establish optimal conditions for high remeasurement efficiency in FTICR.

Main Methods:

• Utilized repetitive chirp excitation, filtered noise excitation, and high-amplitude, single-frequency excitation.
• Performed experiments in a 4.7 T FTICR spectrometer with an open-ended cylindrical analyzer cell.
• Investigated ion loss mechanisms, particularly z-axis ejection during detection.

Main Results:

• Achieved high remeasurement efficiencies: >99.5% for chirp excitation, 99% for filtered noise, and 99.4% for single-frequency excitation.
• Identified z-axis ion ejection during detection as the primary cause of ion loss.
• Demonstrated the necessity of capacitive coupling of excitation signals to trapping plates for high remeasurement efficiency.

Conclusions:

• Broad quadrupolar excitation methods enable efficient ion axialization across a wide mass range in FTICR.
• Minimizing z-axis ion ejection and employing capacitive coupling are critical for maximizing ion remeasurement efficiency.
• These findings advance the capabilities of FTICR mass spectrometry for complex analyses.