Analysis of selenomethylselenocysteine and selenomethionine by LC-ESI-MS/MS with diethyl ethoxymethylenemalonate derivatization.
A simple method to identify and determine Selenomethionine (SeMet) and Selenomethylselenocysteine (Se-MeSeCys) with diethyl ethoxymethylenemalonate (DEEMM) derivatization and LC-ESI-MS/MS determination was developed. Separation of SeMet and Se-MeSeCys was achieved in 15.3 minutes. The calibration graph was linear in the range of 0.32 pmol to 49 pmol for SeMet and 0.34 pmol to 40 pmol for Se-MeSeCys. To prevent oxidation of SeMet, 2-mercaptoethanol was introduced to the calibration solutions. Detection limits were 0.1 pmol, which are comparable to LC-ICP-MS analysis. The developed method therefore offers an alternative to LC-ICP-MS offering similar sensitivity and additionally allows identification. The method was used to determine Se-MeSeCys and SeMet in onion samples.
Institute of Chemistry, University of Tartu, Estonia.
Riin
R
Rebane
Koit
K
Herodes
Ivo
I
Leito
D002851:Chromatography, High Pressure Liquid; D003545:Cysteine / Q000031:analogs & derivatives* / Q000032:analysis; D008314:Malonates / Q000737:chemistry*; D008623:Mercaptoethanol / Q000737:chemistry; D019697:Onions / Q000737:chemistry; D016566:Organoselenium Compounds / Q000032:analysis*; D010084:Oxidation-Reduction; D017279:Selenocysteine / Q000031:analogs & derivatives; D012645:Selenomethionine / Q000032:analysis*; D021241:Spectrometry, Mass, Electrospray Ionization
D008314:Malonates; D016566:Organoselenium Compounds; D017279:Selenocysteine; D008623:Mercaptoethanol; C044472:diethyl (ethoxymethylene)malonate; D012645:Selenomethionine; D003545:Cysteine; C002979:selenomethylselenocysteine