Densitometric determination of carbohydrates: Application to purification and molecular weight determination of polysaccharide from Hericium erinaceum mushroom

A simple, precise, sensitive and quick densitometric method for quantitative total carbohydrate determination as well as for preparation of elution profiles of polysaccharides was developed and validated. The method is based on spotting 3 μL of sample solution by use of disposable micro capillary pipettes as a single drop on a TLC silica gel plate. The plate is then submitted to in situ derivatization with orcinol–sulfuric acid reagent and is scanned densitometrically at 560 nm (for hexoses, deoxy sugars, and uronic acids) or at 610 nm (for pentoses and ketoses). It was demonstrated that the densitometric method has a greater linearity range and similar precision in comparison to the widely used colorimetric phenol–sulfuric acid method. The proposed method was successfully applied to elution profile preparation during purification and molecular weight determination of a novel polysaccharide isolated from the mycelium of edible and medicinal mushroom Hericium erinaceum.