Minimization of Isoamylase Interference in Size-Exclusion Chromatography of Debranched Starch Molecular Structure

Size-exclusion chromatography (SEC) of sodium acetate buffer, denatured isoamylase, and debranched starch is used with various NaCl concentration as mobile phase to identify and minimize interference of buffer and isoamylase in analysis of debranched starch molecular structure. Also, superdex (SD) 75, SD 75 + SD 30, or SD 200 + SD 30 is used to compare SEC results under different columns. When a deionized water is used as mobile phase, elution times of each buffer and isoamylase are overlapped with molecular distribution of debranched starch in all column conditions. Higher NaCl concentration of mobile phase delays elution time of isoamylase in all column conditions but does not change fractionation behavior of debranched starch chains. Elution time of isoamylase is overlapped with that of debranched starch at higher than 200 mM of NaCl concentration with SD 75. In SD 75 + SD 30 and SD 200 + SD 30 column, elution of isoamylase completely separate with that of debranched starch when NaCl concentration of mobile phase is higher than 50 mM. Overall, the interference is minimized by addition of NaCl to mobile phase with SD 75 + SD 30 and SD 200 + SD 30 column.