Large-scale identification of selenium metabolites by online size-exclusion-reversed phase liquid chromatography with combined inductively coupled plasma (ICP-MS) and electrospray ionization linear trap-Orbitrap mass spectrometry (ESI-MS(n))

in Metallomics (2012), 4(5), 422-432

A method was developed for the comprehensive cartography of the selenium metabolites synthesized in the process of conversion of selenite [Se(IV)] into organic compounds and enrichment of yeast with ... [more ▼]

A method was developed for the comprehensive cartography of the selenium metabolites synthesized in the process of conversion of selenite [Se(IV)] into organic compounds and enrichment of yeast with selenium. The number of compounds detected was considerably increased (49) owing to the optimization of the fractionation procedure and the use of UPLC. The increased purity of the minor selenoorganic amino acids and oligopeptides allowed successful on-line de-novo identification based on the exact mass (o1 ppm) and fragmentation (MS2/MS3) mass spectra obtained with high resolution and high mass accuracy. The quality of mass spectra allowed the re-interpretation of previously reported structures of some selenium species. [less ▲]

Recent advances in analytical chemistry and mass spectrometry for organic selenium and tellurium compounds

in Rappoport, Zvi (Ed.) The Chemistry of Organic Selenium and Tellurium compounds Volume 3 Part 1 and 2 (2012)

The objective of this chapter is to present the recent developments in mass spectrometry for selenium (Se) and tellurium (Te) analysis. The state-of-the-art of mass spectrometry based techniques available ... [more ▼]

The objective of this chapter is to present the recent developments in mass spectrometry for selenium (Se) and tellurium (Te) analysis. The state-of-the-art of mass spectrometry based techniques available is critically evaluated with particular emphasis in ion sources and mass analyzers. The complexity of identification and characterization of Se, Te species including their speciation in the environment or in biological materials requires methodologies not only limited to mass spectrometry. Particular attention is given to sample preparation and hyphenated techniques with mass spectrometry for a comprehensive characterization of these trace elements. All these aspects are illustrated with up-to-date applications from the literature. Finally, future trends in mass spectrometry give the readers new insights in Se and Te species detection. [less ▲]

Contribution of multidimensional liquid chromatography with Inductively Coupled Plasma Mass Spectrometry and Ion Mobility Mass Spectrometry detection in speciation analyses of selenium containing from selenium-rich yeasts

Poster (2011, June)

Mass spectrometry applied to biomolecules analysis

Conference (2011, March 31)

Study of the Se-containing metabolomes in Se-rich yeast by size-exclusion-cation-exchange HPLC with the parallel ICP MS and electrospray orbital ion trap detection

in Metallomics (2010), 2(8), 535-548

Strong cation exchange HPLC with the parallel ICP MS and electrospray hybrid linear ion trap quadrupole orbital trap mass spectrometry (ESI Orbitrap MS) detection was developed for the study of the ... [more ▼]

Strong cation exchange HPLC with the parallel ICP MS and electrospray hybrid linear ion trap quadrupole orbital trap mass spectrometry (ESI Orbitrap MS) detection was developed for the study of the metabolomic pattern of selenium in selenium-rich yeast. The mobile phase composition (gradient of ammonium formate in 20% methanol) was optimized to obtain separation in conditions guaranteeing the identical ICP MS sensitivity during the entire chromatographic run and the compatibility with electrospray ionization. Twenty seven Se-containing metabolites observed in the HPLC-ICP MS chromatogram were identified by ESI Orbitrap MS based on the Se isotopic pattern, the accurate molecular mass, and the multistage fragmentation patterns. The method allowed for the first time the correlation of the differences observed in HPLC-ICP MS chromatography of water extracts of Se-rich yeast samples from different manufacturers with the identity of the eluted compounds determined by ESI MS. [less ▲]

Detection and identification of hydrophilic selenium compounds in selenium-rich yeast by size exclusion-microbore normal-phase HPLC with the on-line ICP-MS and electrospray Q-TOF-MS detection

in Analytica Chimica Acta (2010), 657(2),

Normal-phase HPLC and hydrophilic interaction HPLC (HILIC) were investigated for the separation of selenometabolites in a water extract of Se-rich yeast prior to their detection by ICP-MS and ... [more ▼]

Normal-phase HPLC and hydrophilic interaction HPLC (HILIC) were investigated for the separation of selenometabolites in a water extract of Se-rich yeast prior to their detection by ICP-MS and identification by electrospray MS/MS. The targeted fraction was a low-abundant fraction co-eluting with salt and sulfur analogues in size-exclusion chromatography which has so far been inaccessible to Se speciation studies. The optimization of the separation conditions resulted in the highest separation efficiency when HILIC was used and elution was carried out isocratically with a low concentration ammonium acetate buffer (1 mM ammonium acetate/10mM acetic acid) in 80% acetonitrile. Out of 15 peaks observed with the Se-specific ICP-MS detection 12 was identified by electrospray Q-TOF MS/MS (2,3-dihydroxypropionyl (DHP)-Se-methylselenocysteine [M+H](+): 272, Se-methyl-gamma-glutamyl-selenocysteinylglycine dioxide [M+H](+): 402, gamma-glutanlyl-Se-methylselenocysteine[M+H](+): 313; isomers of gamma-glutamylselenocystathionine [M+H](+): 400; Se-methyl-selenoglutathione [M+H](+): 370, isomers of N-acetylselenocystathionine [M+H](+): 313, 2,3-DHP-selenohomolanthionine [M+H](+): 373, isomers of 2,3-DHP-seienocystathionine[M+H](+): 359,2,3-DHP-selenolanthionine [M+H](+): 345 and selenohomolanthionine [M+H](+): 285). (C) 2009 Elsevier B.V. All rights reserved. [less ▲]