Identification of anionic selenium species in Se-rich yeast by electrospray QTOF MS/MS and hybrid linear ion trap/orbitrap MSn

Abstract

An analytical approach allowing the identification of unknown selenium metabolites in selenium-rich yeast was described. Anion-exchange HPLC of the Se-metabolome fraction co-eluting with salts in size-exclusion chromatography allowed the separation of nine selenium species (excluding isomers and selenate) as monitored by inductively coupled plasma mass spectrometry (ICP MS). The individual fractions were analyzed by electrospray QTOF MS/MS and hybrid linear ion trap/Orbitrap MSn after sample introduction by reversed-phase nanoHPLC and by hydrophilic interaction LC (HILIC), respectively. Out of the nine detected species, eight were identified on the basis of accurate mass measurements and collision induced dissociation/fragmentation information. Seven Se-species (selenohomolanthionine, γ-Glu-selenocystathionine, 2,3-DHP-selenocystathionine, N-acetyl-selenocystathionine, 2,3-DHP-selenohomolanthionine, Se-methyl-selenoglutathione, and 2,3-DHP-Se-methylselenocysteine) were reported for the first time in Se-rich yeast, five of them have never been reported in any biological sample before.

Influence of Speciation on the Response from Selenium to UV-Photochemical Vapor Generation

“…10 Intrinsically volatile selenium species have been characterized by GC-MS, 12 and anionic species by ESI. 13 The large number of selenoamino peptides of interest and their range of concentration in samples has also identified the need for their quantitation at ultra-trace levels.…”

Elemental and Isotopic Mass Spectrometry

“…There are also reported two interesting articles that concern Se-containing metabolomes and anionic Se species in Se-rich yeast by SEC-ICP-MS [149,150]. There are also reported two interesting articles that concern Se-containing metabolomes and anionic Se species in Se-rich yeast by SEC-ICP-MS [149,150].…”

Separation Technique for the Determination of Highly Polar Metabolites in Biological Samples

“…confirmed the potential of electrospray quadrupole time-of-flight (QTOF) MS/MS for the identification of selenium metabolites, such as GSH conjugate, which is in the low intra scan dynamic range [98]. Iwasaki et al .…”