A device and system for reversibly trapping and isolating carbohydrate moieties. The apparatus includes an aldehyde-containing trapping material, a trapping means into which the aldehyde-containing trapping material is packable and through which hydrazine-activated carbohydrate-containing samples are passable, and additional hydrazine to release hydrazine-activated carbohydrates from the trapping material. As a result, all remaining non-carbohydrate material is not bound to the apparatus.