Large scale fractionation of pullulan and dextran

A recently developed large scale fractionation technique named continuous spin fractionation (CSF) was applied to fractionate pullulan and dextran. 450 g of pullulan with a broad molecular weight distribution were fractionated using water as solvent and acetone as precipitant. In this study, we have in five CSF runs prepared three fractions with apparent M¯w* values ranging from 17.6 to 413 kg mol−1. Seventy grams of dextran were fractionated with a mixed solvent of water plus methanol. Five fractionation steps resulted in four samples with M¯w values between 4.36 and 18.2 kg mol−1.