Determination of molecular mass distribution of amylopectin using asymmetrical flow field-flow fractionation

The molar mass (Mw), radius of gyration (Rg), diffusion co-efficient (D), and hydrodynamic radius (Rh) of amylopectin (waxy maize starch) has been determined using asymmetrical flow field-flow fractionation coupled with multi-angle light scattering and refractive index detectors (AF4/MALS/RI). A high pressure microwave vessel (HPMV) was used to dissolve amylopectin in 1 M KSCN. The effect of varying the flow rates on the Mw and Rg distributions of amylopectin were investigated to determine the optimum flow rates. The average Mw and Rg values of amylopectin determined using the Berry and Debye equations. D and Rh values were determined directly from the AF4 retention times and compared to values obtained by dynamic light scattering.