Distinguishing between Isobaric Ions Using Microdroplet Hydrogen–Deuterium Exchange Mass Spectrometry

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.

Peptide Oxidation Induced by Liquid–Solid Contact Electrification as Revealed in Liquid Microjunction-Surface Sampling Probe Mass Spectrometry

“…For instance, when studying pharmaceutical compounds using MS, the oxidized peak may be incorrectly assigned to drug metabolites that are isomeric or structurally identical to the oxidized product . In addition to conventional qualitative analysis, ambient ionization techniques have been incorporated into hydrogen/deuterium exchange MS in several previous studies. − Overlapping signals corresponding to oxidized species and partially deuterated species would negatively impact the accuracy of determining the deuterium uptake number . In light of these issues, it is crucial to identify feasible approaches to eliminate oxidation from MS analysis.…”

Mass spectrometry imaging advances and application in pharmaceutical research

“…A relatively confident result for an ion identification could be assured by chemometrics based on multiple matching criteria, including exact mass tolerance, isotope abundance, adduct ion types, and featured fragments [117][118][119]. Apart from the post-acquisition dry method, the online wet experiments also provide complementary chemical structure to help isobaric ion differentiation, such as hydrogen-deuterium exchange (HDX) during the ionization process in the liquid phase or and post-ionization traveling process in the gas phase [120,121].…”

Silicone Wristband Spray Ionization Mass Spectrometry for Combined Exposome and Metabolome Profiling

“…Coupling of wristband technology with HR‐MS can enable the evaluation of environmental contaminates, screen unexpected chemical exposures, and capture information about pesticides, flame retardants, polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs) [27] . We previously used polymer‐based spray ionization mass spectrometry for the metabolomic and lipidomic profiling of biological fluid samples [17,22–26] . It has advantages in rapid screening and in vitro diagnosis of disease, identification of discriminative biomarkers and dysregulated pathways, and even illumination of gene‐environment interactions, and disease‐relevant genomic regions [28] …”

“…[14,15] Recent studies demonstrated that polymer-based spray ionization coupled with high-resolution mass spectrometry (HR-MS) provides a promising approach for molecular and metabolic profiling and quantitation of biological fluids. [16][17][18][19][20][21][22][23][24][25][26] Coupling of wristband technology with HR-MS can enable the evaluation of environmental contaminates, screen unexpected chemical exposures, and capture information about pesticides, flame retardants, polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs). [27] We previously used polymerbased spray ionization mass spectrometry for the metabolomic and lipidomic profiling of biological fluid samples.…”

“…[27] We previously used polymerbased spray ionization mass spectrometry for the metabolomic and lipidomic profiling of biological fluid samples. [17,[22][23][24][25][26] It has advantages in rapid screening and in vitro diagnosis of disease, identification of discriminative biomarkers and dysregulated pathways, and even illumination of gene-environment interactions, and disease-relevant genomic regions. [28] We report here the development of in situ sampling coupled with an ambient ionization method, which we name silicone wristband electrospray ionization mass spectrometry (SWESI-MS), to detect some model compounds derived from drink, diet, smoke, and medicine (caffeine, acetaminophen, urea, and nicotine).…”