A Modular Variable Temperature FT-IMS Instrument Optimized for Gas-Phase Ion Chemistry Applications.

Area of Science:

• Analytical Chemistry
• Physical Chemistry
• Spectroscopy

Background:

• Ion mobility spectrometry (IMS) is a powerful analytical technique for separating ions based on their size, shape, and charge.
• Understanding ion-neutral interactions is crucial for interpreting IMS data and reaction kinetics.
• Previous studies have primarily focused on IMS experiments conducted at ambient temperatures.

Purpose of the Study:

• To characterize and optimize a modular, open-source rolled ion mobility spectrometer for heated ion chemistry experiments.
• To investigate the effect of elevated temperatures on ion-neutral interactions and chemical reactions within the drift cell.
• To evaluate the analytical performance of multiplexed mobility data acquisition modes.

Main Methods:

• Development and characterization of a heated, open-source ion mobility spectrometer with minimal outgassing materials.
• Conducting deuterium incorporation and hydrogen/deuterium exchange experiments at various elevated temperatures.
• Comparative analysis of traditional signal-averaging and Fourier Transform-IMS (FT-IMS) data processing techniques.

Main Results:

• Elevated temperatures significantly increase deuterium incorporation and facilitate hydrogen/deuterium exchanges.
• Fast ion-neutral exchange rates increase with temperature, while slow exchange rates attributed to ion-neutral clustering remain constant.
• No significant changes in mobility shifts were observed for slow exchange processes.
• Multiplexing mobility data using FT-IMS demonstrates analytical merit compared to traditional signal-averaging.

Conclusions:

• Heated ion mobility spectrometry is a valuable tool for studying temperature-dependent ion chemistry and reaction kinetics.
• Temperature control in IMS provides a means to access and study reaction pathways not observable at ambient conditions.
• FT-IMS offers enhanced analytical capabilities for processing multiplexed mobility data in heated experiments.