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We investigate cross-correlation between B quadrupole and B-F dipole-dipole coupling in two BODIPY compounds and one bis(benzoxazol)methanide in partially oriented polystyrene (PS) samples. Especially for the bis(benzoxazol)methanide, the transitions for which the two interactions interfere con- or destructively clearly show distinct linewidths.
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http://dx.doi.org/10.1002/mrc.5507 | DOI Listing |
Magn Reson Chem
March 2025
Institut für Anorganische Chemie, Georg-August-Universität Göttingen, Göttingen, Germany.
We investigate cross-correlation between B quadrupole and B-F dipole-dipole coupling in two BODIPY compounds and one bis(benzoxazol)methanide in partially oriented polystyrene (PS) samples. Especially for the bis(benzoxazol)methanide, the transitions for which the two interactions interfere con- or destructively clearly show distinct linewidths.
View Article and Find Full Text PDFACS Omega
October 2024
Research Analytical Biochemistry Laboratory, Department of Chemistry and Biology, Toronto Metropolitan University, Toronto M5B 2K3, Canada.
Previous meta-analysis indicated that plasma or serum proteome groups using various experimental conditions detected different peptides from the same plasma proteins, which is strong evidence for the veracity of blood fluid LC-ESI-MS/MS but also evidences that the trypsin digestion step is a key source of variation in plasma proteomics. Agreement between different digestion conditions and MS/MS algorithms may serve as an independent confirmation of the validity of the LC-ESI-MS/MS analysis of plasma peptides. Plasma contains a high percentage of albumin held together by multiple disulfide bonds; hence, reduction and/or alkylation may greatly enhance the digestion efficiency of albumin.
View Article and Find Full Text PDFAnal Biochem
June 2024
Research Analytical Biochemistry Laboratory (RABL), Department of Chemistry and Biology, Toronto Metropolitan University, Canada. Electronic address:
The naturally occurring peptides and digested proteins of fetal versus adult bovine serum were compared by LC-ESI-MS/MS after correction against noise from blank injections and random MS/MS spectra as statistical controls. Serum peptides were extracted by differential precipitation with mixtures of acetonitrile and water. Serum proteins were separated by partition chromatography over quaternary amine resin followed by tryptic digestion.
View Article and Find Full Text PDFProg Nucl Magn Reson Spectrosc
June 2020
Department of Chemistry, Queen's University, 90 Bader Lane, Kingston, Ontario K7L 3N6, Canada. Electronic address:
This review describes the latest developments in the field of O NMR spectroscopy of organic and biological molecules both in aqueous solution and in the solid state. In the first part of the review, a general theoretical description of the nuclear quadrupole relaxation process in isotropic liquids is presented at a mathematical level suitable for non-specialists. In addition to the first-order quadrupole interaction, the theory also includes additional relaxation mechanisms such as the second-order quadrupole interaction and its cross correlation with shielding anisotropy.
View Article and Find Full Text PDFRapid Commun Mass Spectrom
July 2019
Swiss Federal Laboratories for Materials Science and Technology (Empa), Überlandstrasse 129, CH-8600, Dübendorf, Switzerland.
Rationale: Species with ionization energies beyond what is accessible using state-of-the-art lab sources are affected by poor detection limits in ordinary mass spectrometry setups, whose throughput is also often limited. Extreme ultraviolet (XUV) photoionization mass spectrometry, in combination with linear time-of-flight (TOF), is necessary for the sensitive detection of high ionization energy compounds at trace level. XUV photoionization is available at beamlines, although with limited access.
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