Journal: Analytical Chemistry

Abbreviation

Anal. Chem.

Publisher

American Chemical Society

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ISSN

1520-6882
0003-2700

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Publications 1 - 10 of 320
  • Determining the Regiochemistry and Relative Stereochemistry of Small and Druglike Molecules Using an Alignment Algorithm for Infrared Spectra
    Item type: Journal Article
    Böselt, Lennard; Dötzer, Reinhard; Steiner, Sandra; et al. (2020)
    Analytical Chemistry
    The relative stereochemistry and isomeric substitution pattern of organic molecules is typically determined using nuclear magnetic resonance spectroscopy (NMR). However, NMR spectra are sometimes nonconclusive, e.g., if spectra are extremely crowded, coupling patterns are not resolved, or if symmetry reasons preclude interpretation. Infrared spectroscopy (IR) can provide additional information in such cases, because IR represents a molecule comprehensively by depiction of the complete set of its normal vibrations. The challenge is thereby that diastereomers and substitution isomers often give rise to highly similar IR spectra, and visual distinction is insufficient and may be biased. Here we show the adaptation of an alignment algorithm, originally developed for vibrational circular dichroism (VCD) spectroscopy, to automatically match IR spectra and provide a quantitative measure of the goodness of fit, which can be used to distinguish isomers. The performance of the approach is demonstrated for different use cases: diastereomers of flexible druglike molecules, E/Z-isomers, and substitution isomers of pyrazine and naphthalene. It can be applied to IR spectra measured both in the gas phase (gas chromatography IR) and in solution. © 2020 American Chemical Society
  • Self-Aliquoting Microarray Plates for Accurate Quantitative Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry
    Item type: Journal Article
    Pabst, Martin; Fagerer, Stephan R.; Kohling, Rudolf; et al. (2013)
    Analytical Chemistry
  • Recent Advances in the Analysis of Single Cells
    Item type: Review Article
    Armbrecht, Lucas; Dittrich, Petra S. (2017)
    Analytical Chemistry
  • A New, Modular Mass Calibrant for High-Mass MALDI-MS
    Item type: Journal Article
    Weidmann, Simon; Barylyuk, Konstantin; Nespovitaya, Nadezhda; et al. (2013)
    Analytical Chemistry
  • Analyte templating
    Item type: Journal Article
    Gavioli, Elena; Maier, Norbert M.; Haupt, Karsten; et al. (2005)
    Analytical Chemistry
  • High-Throughput Monitoring of Cocaine and its Metabolites in Hair Using Microarrays for Mass Spectrometry and MALDI-MS/MS
    Item type: Journal Article
    Kernalléguen, Angéline; Steinhoff, Robert F.; Bachler, Simon; et al. (2018)
    Analytical Chemistry
  • Integrating Multiple MS Techniques for in-Depth Antibody Glycosylation Analysis: Revealing Glycosylation-Dependent Structural and Functional Properties
    Item type: Journal Article
    Zhou, Yuye; Schedin Weiss, Sophia; Tan, Congrui; et al. (2025)
    Analytical Chemistry
    Glycosylation plays a critical role in modulating protein structure, stability, and binding properties, yet comprehensive tools to systematically characterize these effects are scarce. Here, we integrated multiple mass spectrometry (MS) techniques, including high-resolution nanoelectrospray ionization MS (nESI-MS), cross-linking matrix-assisted laser desorption/ionization time-of-flight MS (XL-MALDI-MS), native MS, ion mobility mass spectrometry (IM-MS), together with collision-induced unfolding and a temperature-controlled nESI source to comprehensively investigate glycosylation-dependent changes in protein structural and functional properties. Applying this integrated platform to human IgG Fc, we uncovered how glycosylation alterations in hospitalized COVID-19 patients impact Fc conformation, stability, and receptor binding. nESI-MS profiling revealed a loss of core fucosylation, galactosylation, and sialylation in patient samples. These changes in glycosylation, particularly the loss of fucosylation (afucosylation), correlate with enhanced FcγRIIIa binding, a more open conformation, and reduced stability. These findings highlight glycosylation as a key factor in immune dysregulation during severe COVID-19, and demonstrate the power of integrating multiple MS techniques to uncover the structural and functional consequences of glycan variation. This integrated MS platform is broadly applicable to other glycoprotein systems, including quality control in glycoengineering and research on infectious diseases.
  • High-Precision Oxygen-Isotope Analysis of Iron (Oxyhydr)oxides Using High-Temperature Conversion Isotope Ratio Mass Spectrometry
    Item type: Journal Article
    Galili, Nir; Somlyay, Anna; Aquila, Giorgia; et al. (2025)
    Analytical Chemistry
    We introduce a novel high-precision method for oxygen-isotope analysis of iron (oxyhydr)oxides using high-temperature conversion isotope ratio mass spectrometry (HTC-IRMS). In this approach, a finely ground mixture of iron (oxyhydr)oxide and graphite is heated at 1450 °C in a helium flow environment, converting oxygen to CO gas with nearly 100% yield. Continuous-flow IRMS analysis of the liberated CO yields a precision of ±0.15‰ (1σ, n = 28) and shows excellent agreement with (and improved precision over) traditional fluorination methods. This practical and safe technique expands access to oxygen-isotope measurements of iron oxides, thereby enhancing their utility in Earth and environmental sciences.
  • Multiplexed Detection of Tumor Markers and Discrimination of Cancer Cell Types by Laser Ablation-Dielectric Barrier Discharge Ionization-Mass Spectrometry
    Item type: Journal Article
    Guan, Xiaokang; Lu, Qiao; Wei, Naijie; et al. (2025)
    Analytical Chemistry
    We present an ambient mass spectrometry immunoassay platform based on specific mass tags detected by laser ablation-dielectric barrier discharge ionization-mass spectrometry (LA-DBDI-MS). It features high sensitivity, multiplexed quantitation, minimal sample consumption, and convenient operation. The organic small-molecule mass tags allow very high sensitivity and quantitative detection of multiple proteins, even of membrane-bound proteins on cell surfaces, through signal amplification (approximately 600 times). By using just 2 μL of serum, we achieved the detection of thrombin (LOD 6.6 pM) and cancer antigen 125 (CA125) (LOD 1.4 U/mL). Seven protein biomarkers, including CA125, carcinoembryonic antigen (CEA), epithelial cell adhesion molecule (EpCAM), protein tyrosine kinase 7 (PTK7), transferrin receptor 1 (CD71), cluster of differentiation 8 alpha protein (CD8a), and cluster of differentiation 33 (CD33), were simultaneously detected in situ in four types of cancer cells within 2 h. This platform is expected to enable multiplexed protein detection in single-drop samples or at the single-cell scale, distinguish different types of cells, and has potential applications in clinical diagnosis.
  • Orthogonal Investigation at Single-Particle and Ensemble Levels Uncovers Lipoprotein-Extracellular Vesicle Binding
    Item type: Journal Article
    Musicò, Angelo; Frigerio, Roberto; Normak, Karl; et al. (2026)
    Analytical Chemistry
    Mesoscale interactions critically shape the biological identity of extracellular nanoparticles, including extracellular vesicles. These interactions encompass biomolecular coronas, transient aggregation, and fusion events. Among them, the interaction between extracellular vesicles and lipoproteins has recently garnered significant attention due to their potential impact on functionality and in vivo fate of extracellular vesicles. In this work, we present a first investigation of the binding between human red blood cell-derived extracellular vesicles and lipoproteins across multiple scales, in both buffer and plasma. Red blood cell-derived extracellular vesicles were selected as a model system for their physicochemical homogeneity, potential in personalized medicine, and production scalability. To achieve this, we employed an ad hoc suite of orthogonal analytical techniques: fluorescence cross-correlation spectroscopy (FCCS), super-resolution microscopy, flow cytometry, and Single Molecule Array assays (Simoa). Our results reveal class-specific and context-dependent extracellular vesicle-lipoprotein associations. Notably, lipoproteins bind to extracellular vesicles with affinities ranging from 10 nM to 1 mu M and with up to 100% extracellular vesicles interacting with high-density lipoproteins in the presence of plasma proteins. These findings uncover a complex and dynamic interactome of red blood cell-derived extracellular vesicles across lipoprotein classes. This work establishes a robust methodological framework for studying mesoscale interactions of extracellular nanoparticles under physiologically relevant conditions. Its versatility allows for its application to diverse interaction scenarios, supporting systematic investigation of context-dependent effects on EV-LP binding.
Publications 1 - 10 of 320