High-Throughput Multiplexed Infrared Spectroscopy of Ion Mobility-Separated Species Using Hadamard Transform

Coupling vibrational ion spectroscopy with highresolution ion mobility separation offers a promising approach for detailed analysis of biomolecules in the gas phase. Improvements in the ion mobility technology have made it possible to separate isomers with minor structural differences, and their interrogation with a tunable infrared laser provides vibrational fingerprints for unambiguous database-enabled identification. Nevertheless, wide analytical application of this technique requires high-throughput approaches for acquisition of vibrational spectra of all species present in complex mixtures. In this work, we present a novel multiplexed approach and demonstrate its utility for cryogenic ion spectroscopy of peptides and glycans in mixtures. Since the method is based on Hadamard transform multiplexing, it yields infrared spectra with an increased signal-to-noise ratio compared to a conventional signal averaging approach.

Automated summary

Coupling vibrational ion spectroscopy with high-resolution ion mobility separation allows for detailed analysis of biomolecules in the gas phase. A novel multiplexed approach using Hadamard transform multiplexing is introduced, which improves the signal-to-noise ratio of infrared spectra compared to conventional methods. This study demonstrates the utility of this approach for cryogenic ion spectroscopy of peptides and glycans in mixtures.