The combination of hydrophilic interaction liquid chromatography with electrospray mass spectrometry (HILIC-MS) has been investigated as a tool for the analysis of assorted toxins produced by cyanobacteria. Toxins examined included saxitoxin and its various analogues (1-18), anatoxin-a (ATX-a, 19), cylindrospermopsin (CYN, 20), deoxycylindrospermopsin (doCYN, 21), and microcystins-LR (22) and -RR (23). The saxitoxins could be unequivocally detected in one isocratic analysis using a TSK gel Amide-80 column eluted with 65% B, where eluent A is water and B is a 95% acetonitrile/water solution, both containing 2.0 mM ammonium formate and 3.6 mM formic acid. The analysis of ATX-a, CYN and doCYN required 75% B isocratic. Simultaneous determination of 1-21 was also possible by using gradient elution. HILIC proved to be suitable for the analysis of microcystins, but peak shape was not symmetric and it was concluded that these compounds are best analysed using existing reversed-phase methods. The HILIC-MS method was applied to the analysis of field and cultured samples of Anabaena circinalis and Cylindrospermopsis raciborskii. In general, the method proved quite robust with similar results obtained in two different laboratories using different instrumentation.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1016/j.chroma.2003.11.083 | DOI Listing |
J Oleo Sci
January 2025
Graduate School of Science and Technology, Kumamoto University.
Near-infrared wavelength-selective soft actuators have attracted much attention for applications in microsystems in bioliving. It is desirable for the photothermal conversion materials in the actuators to be downsized to the molecular scale. However, in conventional actuator materials using copolymer gels composed of thermosensitive and photothermal conversion molecule-coordinated monomers, the strong cross-linking of molecules in the networks impairs the actuator deformation.
View Article and Find Full Text PDFAnal Chim Acta
March 2025
Van't Hoff Institute for Molecular Sciences (HIMS), University of Amsterdam, Science Park 904, 1098 XH, Amsterdam, the Netherlands; Centre for Analytical Sciences Amsterdam, Science Park 904, 1098 XH, Amsterdam, the Netherlands. Electronic address:
Background: Persistent and mobile organic compounds (PMOC) are of great concern for water quality and human health. The recent improvement and availability of high-resolution mass spectrometry in combination with liquid chromatography have widely expanded the potential of analytical workflows for their detection and quantitation in water. Given their high polarity, the detection of some PMOC requires alternative techniques to reversed-phase chromatography, such as hydrophilic interaction liquid chromatography (HILIC) and supercritical fluid chromatography (SFC).
View Article and Find Full Text PDFBiopolymers
March 2025
Department of Chemistry, Bose Institute, Kolkata, India.
The stability of α-crystallin, the major protein of the mammalian eye lens and a molecular chaperone, is one of the most crucial factors for its survival and function. The chaperone-like activity and stability of α-crystallin dramatically increased in the presence of Zn. Each subunit of α-crystallin could bind multiple zinc atoms through inter-subunit bridging and cause enhanced stability.
View Article and Find Full Text PDFJ Sep Sci
January 2025
Chair of Environmental Chemistry and Bioanalytics, Faculty of Chemistry, Nicolaus Copernicus University in Toruń, Toruń, Poland.
Oligonucleotides (ONs) are an increasingly popular category of molecules in the pharmaceutical landscape, particularly attractive for the treatment of genetic and rare diseases. However, analyzing these molecules presents significant challenges, due to their highly hydrophilic nature, multiple negative charges, and the presence of closely related impurities resulting from the complex solid-phase synthesis process. Ion pairing reverse-phase liquid chromatography (IP-RPLC) is the preferred technique for ONs analysis but is not ideal for mass spectrometry (MS) coupling.
View Article and Find Full Text PDFBiomacromolecules
January 2025
BOKU-University, Institute of Physics and Materials Science, Vienna, Peter-Jordan-Straße 82, Vienna 1190, Austria.
To understand xylan-cellulose interactions in softwood, the adsorption behavior of hexameric softwood xylan proxies with various substitutions was analyzed on the three surfaces of a hexagonal cellulose microfibril. The study found that all surfaces could bind xylan motifs, showing equally high affinity for the hydrophilic (110) and hydrophobic (100) surfaces and significantly lower affinity for the hydrophilic (11̅0) surface. Unsubstituted xylose hexamers had the highest affinity and most ordered adsorption structures, while substitutions generally reduced the affinity and regularity.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!