Sugars in Popular Drinks
A typical application of HPLC may be illustrated by the identification of glucose, fructose and sucrose in a popular drink such as Pepsi using a 4 mm × 30 cm column of Macropak-NH4 and acetonitrile-water system at a flow rate of 2.0 mL/min as shown in Figure. It is observed that fructose is eluted first followed by glucose and fructose and the whole separation takes about 15 min.
Figure: The HPLC separation of glucose, fructose and sucrose in Pepsi shown as three distinct peaks
However, size exclusion chromatography has been used for qualitative identification and quantitative determination of these sugars in four types of canned fruit juices of apple, orange, pineapple and cranberry, as shown in Figure. Also shown is chromatogram for the standards which can be used for quantitative determination of the constituent sugars. The packing which had an exclusion limit of 1000, was a cross linked-polystyrene polymer made hydrophilic by sulphonation. A 25 cm long column with this packing contained 7600 plates at 80oC.