3.4. Se species analysis of Se-antioxi-Pep by HPLC-ICP-MS
Fig. 4 shows the HPLC-ICP-MS chromatograms of the antioxidative
peptides that were eluted from the DEAE-Sepharose-FF ion-exchange column. SeCys2, MeSeCys, Se (IV), and SeMet were identified
on the basis of their matching retention times with Se standards
(cf. Fig. 1a). It was noted that Se species remarkably varied
between fractions. All four seleno-compounds were found in F3-3,
although SeCys2 and MeSeCys were poorly separated. However,
only SeMet was identified in F5-1. Each fraction contained SeMet
as its major species. Sub-fraction F5-1, which had the highest
antioxidative activity among all the sub-fractions, was chosen for
further identification through ESI FT-ICR MS.