AQUEOUS SIZE-EXCLUSION CHROMATOGRAPHY OF HYDROXYETHYL-AMYLOPECTIN

A modified starch component, hydroxylated amylopectin (HAP), was analy sed by a low angle laser light scattering apparatus used with high-per formance steric exclusion chromatography. The correct weight-average m olecular weight and molecular weight distribution (MWD) have been obta ined and compared with calibration methods used in conventional chroma tography. The modified amylopectin was first chemically scissored and afterwards fractionated using a low-pressure apparatus with crosslinke d agarose gel and with a fraction collector on line. For comparing wit h conventional methods the calibration curves were obtained from polye thylene oxide and polysaccharides provided by Polymer Laboratories. Th e HAP fractions were separated using a three-columns system and degase d buffered filtered water as the mobile phase. This paper discusses th e different valuable methods of calculations leading to the molecular weight and MWD characterisation. Failure in the universal calibration is observed for grafted carbohydrates.