Size exclusion chromatography (SEC) is frequently applied in industries and many labs for Mw and Mw distribution (MwD) determination because of its time and cost efficiency. Since the retention volume of SEC depends on the hydrodynamic volume rather than Mw, the use of globular coil-type standards Pulluan(P)-82, leads to a significant overestimation of Mw of many plant and fungal polysaccharides with flexible chain conformation. In this research, we developed a Mw standards with linear structure and expanded chain conformation. The standard kits were characterized and compared with the performance of P-82.
Materials:
Lentinus edodes (PLE ), Guar galactomannan (GG ), CM-cellulose (CMC )
Shodex P-82, PS-OBG-Mw( From Putus Macromolecular company)
The three polysaccharides in Table 1 showed expanded chain conformation in solution. The Mw determined by using Putus standards are more accurate than Mw determined by using Pullulan-82, compared to their real Mw measured by LLS. Using P-82 to determine Mw of expanded chain leads to a significant overestimation. Noted that such overestimation was not significant for Mw lower than 100K (YBG and SBG in Table 1), what can be explained by the disability of LLS in the measurement of small particle.