Peptide studies using a fast atom bombardment high field mass spectrometer and data system: 3—negative ionization: Mass calibration, data acquisition and structural characterization

1983 ◽  
Vol 10 (6) ◽  
pp. 387-393 ◽  
Author(s):  
Alexander M. Buko ◽  
Lawrence R. Phillips ◽  
Blair A. Fraser
Keyword(s):  
Data Acquisition ◽  
Mass Spectrometer ◽  
Structural Characterization ◽  
High Field ◽  
Fast Atom Bombardment ◽  
Ionization Mass ◽  
Calibration Data ◽  
Field Mass ◽  
Mass Calibration ◽  
Negative Ionization

Solvent-free dynamic nuclear polarization enhancements in organically modified mesoporous silica

2021 ◽  
Author(s):  
Marcos de Oliveira Jr. ◽  
Kevin Herr ◽  
Martin Brodrecht ◽  
Nadia Berenice Haro-Mares ◽  
Till Wissel ◽  
...  
Keyword(s):  
Mesoporous Silica ◽  
Porous Materials ◽  
Structural Characterization ◽  
Dynamic Nuclear Polarization ◽  
High Field ◽  
Nuclear Polarization ◽  
Organically Modified ◽  
Field Dynamic ◽  
Free Dynamic

High-field Dynamic Nuclear Polarization is a powerful tool for the structural characterization of species on the surface of porous materials or nanoparticles. For these studies the main source of polarization...

scholarly journals The Q Exactive HF, a Benchtop Mass Spectrometer with a Pre-filter, High-performance Quadrupole and an Ultra-high-field Orbitrap Analyzer

2014 ◽  
Vol 13 (12) ◽  
pp. 3698-3708 ◽  
Author(s):  
Richard Alexander Scheltema ◽  
Jan-Peter Hauschild ◽  
Oliver Lange ◽  
Daniel Hornburg ◽  
Eduard Denisov ◽  
...  
Keyword(s):  
Mass Spectrometer ◽  
High Field ◽  
High Performance ◽  
Ultra High Field ◽  
Q Exactive ◽  
Orbitrap Analyzer

scholarly journals 662. Identification of Clinically Relevant Microbes with the MasSpec Pen

2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S386-S387
Author(s):  
Sydney C Povilaitis ◽  
Ashish D Chakraborty ◽  
Rachel D Downey ◽  
Sarmistha Bhaduri Hauger ◽  
Livia Eberlin
Keyword(s):  
Mass Spectrometry ◽  
Mass Spectrometer ◽  
Model Performance ◽  
Sample Surface ◽  
Clinical Analysis ◽  
Ambient Ionization ◽  
Rapid Identification ◽  
Negative Ion ◽  
Ionization Mass ◽  
Molecular Features

Abstract Background In the age of antimicrobial resistance, rapid identification of infectious agents is critical for antimicrobial stewardship and effective therapy. To this end, ambient ionization mass spectrometry techniques have been applied for rapid identification of microbes directly from culture isolates. We have developed a handheld, mass spectrometry-based device, the MasSpec Pen, that permits direct molecular analysis of a biological sample in seconds (Scheme 1). Here, we employ the MasSpec Pen to identify clinically relevant microbes directly from culture isolates. Methods Staphylococcus aureus, Staphylococcus epidermidis, Group A and B Streptococcus, Kingella kingae (K.k), and Pseudomonas aeruginosa (P.a) were cultured on 5% sheep’s blood nutrient agar at 37 °C overnight. Colonies were transferred to a glass slide where they were analyzed directly with the MasSpec Pen coupled to a Q Exactive mass spectrometer (Thermo Scientific) in negative ion mode. For MasSpec Pen analysis, a 10 µL droplet of water was held in contact with the sample surface for 3 seconds and then aspirated to the mass spectrometer for analysis. Data was normalized and the molecular features resulting from the analysis solvent and nutrient medium were removed. The least absolute shrinkage and selection operator (lasso) statistical method was used to build classification models for prediction of bacterial identity. Model performance was evaluated by leave-one-out cross-validation and a validation set of samples. Scheme 1: MasSpec Pen workflow Results Various small molecules were detected including metabolites and glycerophospholipid species. The mass spectral profiles for each species exhibited qualitative differences among them (Figure 1). Additionally, several quorum-sensing molecules were observed in P.a. including hydroxy-heptyl-quinoline (m/z 242.155). Lasso statistical classifiers were created to differentiate organisms at the level of Gram type, genus, and species with each model comprised of a sparse set of molecular features. Accuracies of 90% or greater were achieved for all lasso models and as high as 98% for the differentiation of Staphylococcus (Staph.) and Streptococcus (Strep.). Figure 1: Molecular profiles of species analyzed Figure 2: Statistical classification results Conclusion These results demonstrate the potential of the MasSpec Pen as a tool for clinical analysis of infected biospecimens. Disclosures Sydney C. Povilaitis, BA, MS Pen Technologies, Inc. (Other Financial or Material Support, Patent) Livia Eberlin, PhD, MS Pen Technolpogies, Inc. (Board Member, Shareholder)

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