Related Experiment Video
Updated: Aug 17, 2026

Analysis and Specification of Starch Granule Size Distributions
Published on: March 4, 2021
Measurement of the molecular weight distribution of debranched starch
Jeffrey V Castro1, Rachelle M Ward, Robert G Gilbert
1NSW Department of Primary Industries, Yanco Agricultural Institute, PMB Yanco, NSW 2703 Australia.
Abstract:
Combining molecular weight distribution (MWD) data for linear chains of debranched starch from capillary electrophoresis and from size exclusion chromatography (SEC) with detection by differential refractive index and by multi-angle laser light scattering has enabled Mark-Houwink parameters to be determined for linear starch chains. For accurate results, it was found to be important to take SEC band broadening into account, and a methodology for implementing this is presented. This deconvolution technique can be used to reveal features such as maxima or shoulders in the MWD which have qualitative as well as quantitative significance. Remarkably, these data show that the empirical Mark-Houwink relation between molecular weight and hydrodynamic volume is, for linear debranched starch, valid for much lower molecular weights than synthetic polymers. This implies that these Mark-Houwink parameters can be used with "universal calibration" to enable SEC to be used with relative ease to provide MWDs for debranched starch for essentially any degree of polymerization.
Related Concept Videos
Determination of Molar Masses of Polymers II
Molecular Weight of Step-Growth Polymers
As the step-growth polymerization involves step-wise condensation of monomers, the molecular weight also builds up eventually. Consequently, high molecular weight polymers are obtained at the late stages of the polymerization, where 99% of monomers have been consumed.
The extent of the...
Polymers: Molecular Weight Distribution
Polymers: Defining Molecular Weight
The number average molecular weight (Mn) is the summation of the number...
Determination of Molar Masses of Polymers I
SDS-PAGE
A variation of gel electrophoresis, termed polyacrylamide gel electrophoresis (PAGE), is commonly used for separating proteins according to their molecular size by passing them through a polyacrylamide gel. Because of the varying charges associated with amino acid side chains, PAGE can be used to separate intact proteins...

