Oat spelts xylan molecular mass estimation by size exclusion chromatography

This work addresses the investigation of the parameters that may affect the molecular mass estimation of oat spelts xylan (OSX) by size exclusion chromatography (SEC). These parameters, relative to sample preparation and SEC operating conditions, are: xylan concentration, the solvent characteristics, the eluent pH and ionic strength. The SEC experiments were performed on a Sephacryl S-400 HR column. Glycine–NaOH buffer with the pH ranging from 9 to 12.5 was used as eluent. The OSX was dissolved in aqueous solutions of NaOH with concentrations ranging from 0.2 to 0.5 M. The results showed that the xylan concentration and the eluent ionic strength have no significant effect on the determination of the molecular mass. The NaOH concentration in the OSX solution and the eluent pH, have a great influence on the determination of the molecular masses. This is explained by possible changes of OSX–water interactions leading to different hydrodynamic volumes, upon different solution characteristics.