Using Hadamard Transform Multiplexed IR Spectroscopy Together with a Segmented Ion Trap for the Identification of Mobility-Selected Isomers

The high isomericcomplexity of glycans makes them particularlydifficult to analyze. While ultra-high-resolution ion mobility spectrometry(IMS) can offer rapid baseline separation of many glycan isomers,their unambiguous identification remains a challenging task. One approachto solving this problem is to identify mobility-separated isomersby measuring their highly resolved cryogenic vibrational spectra.To be able to apply this approach to complex mixtures at high throughput,we have recently developed a Hadamard transform multiplexed spectroscopictechnique that allows measuring vibrational spectra of all speciesseparated in both IMS and mass spectrometry dimensions in a singlelaser scan. In the current work, we further develop the multiplexingtechnique using ion traps incorporated directly into the IMS devicebased on structures for lossless ion manipulations (SLIM). We alsoshow that multiplexed spectroscopy using perfect sequence matricescan outperform standard multiplexing using Simplex matrices. Lastly,we show that we can increase the measurement speed and throughputfurther by running multiple multiplexing schemes using several SLIMion traps in combination with simultaneous spectroscopic measurementsin the segmented cryogenic ion trap.