Gradient RP-HPLC analysis of a phospholipid, E5564, utilizing water, methanol and phosphoric acid occasionally results in the appearance of a broad unknown peak in the chromatogram before a well-resolved E5564 peak. This unknown peak does not elute in a reproducible fashion with regards to peak shape and retention time, and is not present in chromatograms resulting from injections of the diluent alone. Investigation of this phenomenon revealed that iron ions in sub-ppm levels in the HPLC mobile phase chelated E5564 and the resultant complex(es) comprised the broad peak. The iron source was identified as phosphoric acid, which was used as a mobile phase modifier. Further studies were conducted to characterize the nature of the phospholipid-iron association and resultant complex.
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http://dx.doi.org/10.1002/bmc.232 | DOI Listing |
Proc Natl Acad Sci U S A
December 2024
Geowissenschaftliches Zentrum, Abteilung für Geochemie und Isotopengeologie, Georg-August-Universität Göttingen, Göttingen 37077, Germany.
The Moon formed 4.5 Ga ago through a collision between proto-Earth and a planetesimal known as Theia. The compositional similarity of Earth and Moon puts tight limits on the isotopic contrast between Theia and proto-Earth, or it requires intense homogenization of Theia and proto-Earth material during and in the aftermath of the Moon-forming impact, or a combination of both.
View Article and Find Full Text PDFAnal Chim Acta
January 2025
Hebei University, Baoding, 071002, China; State Key Laboratory of Medical Proteomics, Beijing Proteome Research Center, National Center for Protein Sciences (Beijing), Beijing Institute of Lifeomics, Beijing, 102206, China. Electronic address:
Background: Host Cell Proteins (HCPs) are impurities expressed in host cells during the biopharmaceutical production process, whichmay compromise product quality and potentially leading to immunogenic reactions or other adverse effects. Mass spectrometry (MS)-based strategy is more and more considered as a promising method for HCPs analysis, since it is capable of simultaneously quantifying thousands of proteins in a single test. However, considering the large excess biopharmaceutical product protein present in the system and the extremely low abundance of HCPs, sensitive MS methods are urgently needed in HCPs analysis.
View Article and Find Full Text PDFAnalyst
October 2024
Human Phenome Institute, Fudan University, Shanghai 200438, P.R. China.
A highly sensitive fluorescence sensor for monitoring low concentrations of hydrogen peroxide was designed. The sensor employs the commercially available palladium or platinum metal on activated charcoal as catalysts to decompose hydrogen peroxide into water and molecular oxygen. The produced oxygen concentration can be measured in real time using an oxygen-sensitive layer doped with photostable oxygen probes.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
September 2024
Department of Chemical and Biomolecular Engineering, National University of Singapore, 4 Engineering Drive 4, Singapore, 117585, Singapore.
Sci Rep
August 2024
Korea Basic Science Institute, Gwangju Center, Chengju-si, Chungcheongbuk-do, 28119, South Korea.
REBa Cu O (REBCO, RE = rare earth)-coated conductor is a competitive option in terms of current-carrying capacity and high-stress durability in developing high-field magnets for nuclear magnetic resonance (NMR) research. Meanwhile, a technical challenge in utilizing a stand-alone REBCO NMR magnet is an unexpected difference in the field uniformity between the designed and measured values after being constructed and charged, i.e.
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