Adding a new separation dimension to MS and LC–MS: What is the utility of ion mobility spectrometry?

Abstract

* These authors contributed equally.Ion mobility spectrometry is an analytical technique known for more than 100 years, which entails separating ions in the gas phase based on their size, shape, and charge. While ion mobility spectrometry alone can be useful for some applications (mostly security analysis for detecting certain classes of narcotics and explosives), it becomes even more powerful in combination with mass spectrometry and high-performance liquid chromatography. Indeed, the limited resolving power of ion mobility spectrometry alone can be tackled when combining this analytical strategy with mass spectrometry or liquid chromatography with mass spectrometry. Over the last few years, the hyphenation of ion mobility spectrometry to mass spectrometry or liquid chromatography with mass spectrometry has attracted more and more interest, with significant progresses in both technical advances and pioneering applications. This review describes the theoretical background, available technologies, and future capabilities of these techniques. It also highlights a wide range of applications, from small molecules (natural products,

Enhanced CHO Clone Screening: Application of Targeted Locus Amplification and Next‐Generation Sequencing Technologies for Cell Line Development

“…Routine measurement of ion mobility parameters (drift time and collisional cross sections [CCS]) as utilized in this setup improved confidence in the sequence variant identification compared to the standard LC-MS/MS peptide mapping approach, and could additionally distinguish peptides by their CCS value, indicating a structural change (Table S1, Supporting Information). [51] Relative levels of the mutated peptide variants as quantified by extracted ion chromatograms of the two clones were very comparable with the levels from the TLA/NGS method ( Figure 1C; Figure S2, Supporting Information). Clone C seemed to differ more significantly in the mutation levels as determined by the TLA/ NGS, genomic DNA, mRNA level, and LC-MS ( Figure 1C).…”

“…Analysis of the MS/MS fragment spectrum confirmed the methionine to isoleucine/leucine substitution, as predicted by the TLA/NGS (Figure A,B, Supporting Information). Routine measurement of ion mobility parameters (drift time and collisional cross sections [CCS]) as utilized in this setup improved confidence in the sequence variant identification compared to the standard LC–MS/MS peptide mapping approach, and could additionally distinguish peptides by their CCS value, indicating a structural change (Table S1, Supporting Information) . Relative levels of the mutated peptide variants as quantified by extracted ion chromatograms of the two clones were very comparable with the levels from the TLA/NGS method (Figure C; Figure S2, Supporting Information).…”

Adduct ion formation as a tool for the molecular structure assessment of ten isomers in traveling wave and trapped ion mobility spectrometry

“…However, on changing from the TOF to the IMS‐TOF mode, the MS sensitivity reduced by three orders of magnitude, being most pronounced for the TWIMS system (Figure S1, supporting information). This dramatic loss in ion transmission upon use of IMS probably occurs in the high‐pressure region …”

Semi‐quantitative non‐target analysis of water with liquid chromatography/high‐resolution mass spectrometry: How far are we?

“…Secondly, relating the spectrum to a specific structure can be difficult due to the complexity of the spectra. The ion mobility data, similarly to MS/MS spectra, are strongly dependent on the instrumental conditions, which also makes the application of libraries complicated . However, distinguishing isobaric compounds with very similar retention times may become possible, if home‐built libraries are available .…”

“…The interpretation of MS/MS spectra, collision cross‐sections, and action spectra is often tedious as such data are only available in libraries and databases for a limited number of compounds. Both MS/MS spectra and collision cross‐sections also strongly depend on the instrumental parameters used and so far gold standards have not been implemented (compared with electron ionization where a gold standard for ionization energy, 70 eV, is widely accepted). In addition, the need for libraries in general can be seen as a limitation.…”