Numerous sugars exist, including glucose, fructose, sucrose, digo-, and poly saccharides. The varied isomeric forms that sugars take when being analysed constitute the most challenge.
Several monosaccharides also differ from one another in relatively subtle ways, for as by having hydroxyl groups that are positioned differently. In order to separate the six different glucose isomers that may be involved in the study of glucose, fairly complicated separation techniques may be needed. The sole method used to accomplish this is chromatography. No other technique can effectively separate sugars.