Tags: Analytical Seminar


Charge Detection-MS: Opening a New Frontier of Mass Spectrometry

Techniques for the detection of extremely high mass ions or the analysis of heterogenous samples in mass spectrometry are often limited by overlapping charge states and poor resolution.1 The invention of electrospray ionization allowed for ionization of increasingly larger ions in mass spectrometry where multiple charging allows for the mass-to-charge ratio to be much lower than the molecular mass.2 In traditional mass spectrometry, the mass-to-…


Targeted LC–MS/MS Characterization of PFAS in Food Packaging and Their Migration into Food Simulants

Food packaging materials extensively utilize PFAS compounds for their exceptional grease and moisture resistance properties, yet their environmental persistence and potential health implications necessitate robust analytical methodologies.1 The primary analytical challenges arise from PFAS structural diversity, ultra-trace concentrations, and complex matrix interference from packaging substrates. Contemporary LC–MS/MS methodologies address these…


Generative Diffusion-Based De Novo Protein Design of Lipid/CD1-Restricted TCR Mimics

De novo protein design has experienced a renaissance in recent years due to advances in generative diffusion-based approaches to develop high affinity, target-specific binders. However, the ability of these tools to generate “new-to-nature” proteins with unique backbones and amino acid sequences that target lipid/protein assemblies has not yet been explored. Here, we apply an end-to-end design pipeline using RFdiffusionAA, LigandMPNN, Chai-…


Structural Analysis of Intact Glycosaminoglycan Mixtures with Capillary Electrophoresis and High Resolution Tandem Mass Spectrometry

Glycosaminoglycans (GAGs), linear polysaccharides found near the cell membrane as proteoglycans and free oligosaccharides, play important roles regarding cell functions. GAGs have been implicated as potential biomarkers in many diseases like cancer and kidney related diseases and are used as therapeutics for many types of ailments. Because they are highly sulfated, complex GAGs have been analyzed with reverse polarity capillary electrophoresis (…


Tandem-Trapped Ion Mobility Spectrometry for Characterizing Structure and Function of Proteoforms

Cellular processes depend on the coordinated function of all proteoforms—the distinct molecular forms of a protein that arise from mechanisms such as alternative splicing and post-translational modifications. Different proteoforms can have distinct free energy landscapes that may alter their structures, motions, and interactions with other proteins. As a result, changes in proteoforms can alter cellular regulation and lead to…


The Study of N-glycans using HILIC, Ion Mobility, and Mass Spectrometry

N-linked glycosylation is an important post translational modification, and the changes in N-glycan patterns are known to be associated with various human diseases. The study of N-glycans is crucial for the safety and efficacy of biotherapeutics. Tandem mass spectrometry (MS/MS) is a popular method in glycomics where glycans are identified via their mass to charge (m/z) and fragment ions. However, glycans exist as isomers arising from linkage,…


Bioanalytical Applications and Fundamental Studies Enabled by High-Resolution Cyclic Ion Mobility Separations Coupled to Mass Spectrometry

Ion mobility spectrometry-mass spectrometry has emerged as an orthogonal and complementary analytical technique to liquid chromatography-tandem mass spectrometry in omics-based analyses. Carbohydrate-containing molecules, such as human milk oligosaccharides and glycolipids, are notoriously difficult to characterize, largely owing to their high degrees of isomeric heterogeneity. Thus, new analytical methodologies are required to improve the…


Trapped Ion Mobility-Assisted Sequencing and Analysis of Protein Ions

The sequencing of intact proteins within a mass spectrometer enables the profiling of post-translational modification (PTM) crosstalk but is frequently hindered by convoluted spectra and the fact that tandem mass spectrometry (MS/MS) techniques often generate poor sequence coverages when applied to protein ions. Ion mobility spectrometry is a promising tool to overcome the complexity of these spectra by separating ions by their mass- and size-to…


Improving Separation of Stereochemical and Positional Isomers: A Combined HILIC-IM-MS Approach

The fundamental building blocks of life consist of lipids, carbohydrates, proteins, and nucleic acids which are assembled from small repeating monomer subunits. Specifically monosaccharides are the precursors of carbohydrates and amino acids are the building blocks of proteins. These two monomers are chiral (except glycine) and can exist in multiple stereochemical forms making their characterization complex.  While monosaccharides and amino…


Leveraging High-Resolution Ion Mobility-Mass Spectrometry Approaches for Improving Analysis of Metabolites, Illicit Drugs, and Environmental Contaminants

Ion mobility-mass spectrometry (IM-MS) has emerged as a powerful analytical technique in the biological -omics over the last two decades, due to advantages in speed and separation capabilities. Despite its now widespread utility, the resolving power of many commercial IM platforms (~40-60) is often insufficient for resolution of structurally similar compounds such as stereoisomers. This presents a critical need for us to develop higher…
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