GEL-PERMEATION CHROMATOGRAPHIC DETERMINATION OF STARCHES USING ALKALINE ELUENTS

By using a dilute solution hydroxide as eluent in a gel permeation chromatography analysis of natural and modified starches, many of the difficulties encountered with less basic eluent (so-called ghost peaks or memory effects) or with the instability of columns encountered with dimethyl-sulphoxide, are avoided. The system is shown to give reproducible results and no problems with column stability are encountered after several months' use. Either ordinary refractive index detection or after-column complexation with iodine and spectrophotometric detection are used. The latter system is especially suited for the analysis of changes that occur on amylose during various treatments (entsymatic or acid hydrolysis or extrusion).