Cryogenic Gas-phase IR Spectroscopy on a Commercial Ion Mobility-Mass Spectrometry Platform.

Area of Science:

• Analytical Chemistry
• Spectroscopy
• Biophysics

Background:

• Gas-phase infrared (IR) spectroscopy combined with ion mobility spectrometry (IM-MS) offers detailed structural insights for analyte identification.
• Current instrumentation is often custom-built, requiring specialized expertise for operation.

Purpose of the Study:

• To demonstrate messenger-tagging IR spectroscopy on a modified, commercially available Synapt G2-S IM-MS system.
• To adapt existing IM-MS instrumentation for efficient cryogenic ion trapping and IR excitation.
• To overcome barriers in adopting orthogonal IR spectroscopy for routine IM-MS workflows.

Main Methods:

• Messenger-tagging IR spectroscopy was implemented using a cryogenic ion trap integrated into a Synapt G2-S IM-MS.
• Optimized timing cycles and voltage gradients were developed for efficient ion trapping and tagging.
• IR light was used to excite tagged ions prior to mass spectrometry detection.

Main Results:

• Successful demonstration of messenger-tagging IR spectroscopy on a widely used commercial IM-MS platform.
• Characterization of leucine enkephalin using IM-MS-IR.
• Separation and IR spectroscopic analysis of isomeric trisaccharides (cellotriose and melezitose) based on ion mobility.

Conclusions:

• This work presents the first implementation of messenger-tagging IR spectroscopy in a commercial IM-MS system.
• The user-friendly approach facilitates the integration of IR spectroscopy into existing IM-MS workflows.
• This technique enhances the ability to distinguish and identify unknown molecules, particularly in untargeted omics studies.