New separation method for organic and inorganic selenium compounds based on anion exchange chromatography followed by inductively coupled plasma mass spectrometry.
Résumé
We describe a new method for separating the organic and inorganic selenocompounds methaneseleninic acid, selenite, selenate, methylselenocysteine, selenocystine as well as both selenomethionine and its oxidized form. The separation is performed on a Hamilton PRP-X100 column. According to the literature, the oxidized form of selenomethionine-which is easily formed-is eluted close to the dead volume when this column is used. The choice of parahydroxybenzoic acid as mobile phase enabled us to elute all of these species after this oxidized form, resulting in better identification and quantification. The factors determining separation (eluent concentration, pH, gradient) were optimized via an experimental design. Application of the method to yeast and commercial tablets showed that the principal Se compound present was selenomethionine, which was also present in its oxidized form.
Mots clés
Selenium
Speciation
Anion exchange chromatography
Experimental design
Tablet
Selenates
Selenites
Inorganic acids
Selenium compound
Inorganic compound
Organic compounds
pH gradient
Concentration factor
Quantitative analysis
Mobile phase
Elution
Mass spectrometry
Coupled method
Inductive coupling plasma spectrometry
Separation method