Diapositive 1 - de l'Université libre de Bruxelles

Chapitre IVFigure 30: XANES spectra of S-reference compounds (A) Amino acid cystine has a double peakaround 2.473 keV and chondroitin sulphate has a single peak at 2.482 keV (B) Methionine andcystein amino acid spectra display a single peak at 2.473 keV.The XANES spectra of the soluble and insoluble organic matrices of the skeleton ofA. rubens presented a main peak at 2.482 keV and small peaks at 2.473 and 2.476 keV(Figure 31). The main peak was characteristic of sulphated sugars, the 2.473 peak wasdue to the presence of S-containing amino acids (cysteine, methionine) and the 2.476peak to methionine sulphoxide. It must be noticed that in the soluble matrix, theascendant part of the peak at 2.482 did not display the classically observed shoulder.Despite these spectra were not calibrated for a quantitative analysis, the S aminoacid andsulphoxide peaks were more intense in the insoluble matrix.89