Can vibrational spectroscopy finally find Its place in the world of analytical mass spectrometry?

Infrared (IR) spectra of gas-phase ions provide detailed fingerprints that are sensitive to the minutest differences in molecular structure and hence can easily distinguish between isomeric species. Although practiced in many academic research laboratories, gas-phase IR spectroscopy has not yet found its way into the world of analytical mass spectrometry. There are at least two obvious reasons for this: (1) the addition of a spectroscopic dimension to an analytical measurement has typically taken tens of minutes for each species, making it poorly suited to high-throughput analysis; and (2) the complex, expensive lasers required have made spectroscopic measurements impractical for biomedical research.
We have overcome these problems in an approach that combines ultrahighresolution SLIM-based ion mobility, cryogenic IR spectroscopy, and mass in a single instrument. By increasing sensitivity and implementing a multiplexing approach to spectral measurement, we can measure an IR fingerprint spectrum of a molecule in as little as 10 seconds. Moreover, we do this using a simple, user-friendly, fiber-pumped IR laser no larger than a shoebox.
After demonstrating the capabilities of our technique, this talk will focus on its application in distinguishing isomeric glycans and glycan-related metabolites. We also have developed schemes to generate IR reference spectra starting from a relatively small number of simple, readily available standards from which we can grow a database for more complex species.