Separation of Sorbitol and Mannoheptulose from Fructose, Glucose and Sucrose on Reversed-Phase and Amine-Modified HPLC Columns

Abstract

Several reversed-phase and amine-modified HPLC columns known to separate fructose, glucose, and sucrose were studied for their effectiveness in the more difficult separations of glucose from sorbitol and glucose from mannoheptulose. An amine-modified silica column was best for separation of glucose from sorbitol, and a pro-pylamine column was best for separation of glucose from mannoheptulose. Because of reversed order of elution in separating glucose and sorbitol with a carbohydrate column. It could not be used in series with other columns to improve separation. The effectiveness of a column toward these more difficult separations cannot be predicted on the basis of its effectiveness in separating fructose, glucose, and sucrose. To test these findings on a natural mixture, carbohydrates in apple and pear juices, which contain appreciable amounts of sorbitol, were quantified using the amine-modified silica column.