Distinguishing between Isobaric Ions Using Microdroplet Hydrogen-Deuterium Exchange Mass Spectrometry.

Xiaowei Song,Mohammad Mofidfar,Jia Li,Richard N Zare

doi:10.3390/metabo11110728

Xiaowei Song, Mohammad Mofidfar + Show 2 more

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https://doi.org/10.3390/metabo11110728

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Journal: Metabolites	Publication Date: Oct 23, 2021
Citations: 10	License type: CC BY 4.0

Affiliation: Stanford University, Fudan University

Abstract

Isobaric ions having the same mass-to-charge ratio cannot be separately identified by mass spectrometry (MS) alone, but this limitation can be overcome by using hydrogen–deuterium exchange (HDX) in microdroplets. Because isobaric ions may contain a varied number of exchangeable sites and different types of functional groups, each one produces a unique MS spectral pattern after droplet spray HDX without the need for MS/MS experiments or introduction of ion mobility measurements. As an example of the power of this approach, isobaric ions in urinary metabolic profiles are identified and used to distinguish between healthy individuals and those having bladder cancer.

Highlights

Ambient ionization mass spectrometry (AIMS) refers to the strategy that directly analyzes the sample’s composition or target species under atmospheric and room-temperature conditions [1,2]
Glucose and inositol can be readily distinguished by microdroplet hydrogen–deuterium exchange (HDX)/mass spectrometry. We presented this example to illustrate in these situations that the MS/MS patterns are quite close with each other; microdroplet HDX is a much simpler but effective strategy if possible isobaric ions happen to have a different number of exchangeable protons
Because there were more HDX-generated deuterated peaks in the metabolic profiles compared to the pre-HDX metabolic profile, we evaluated the performance of principal component analysis (PCA) on sample clustering according to the native and HDX metabolic profiles, respectively

Summary

Introduction

Ambient ionization mass spectrometry (AIMS) refers to the strategy that directly analyzes the sample’s composition or target species under atmospheric and room-temperature conditions [1,2]. AIMS can successfully detect a wide range of chemical species, such as synthetic drugs; pesticides; and endogenous metabolites, including amino acids, fatty acids, nucleosides, carboxylic acids, carbohydrates, aldehydes, glycerophospholipids, etc. [3,4,5,6,7]

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