Comparative study of different polar adsorbents for adsorption of water soluble vitamins

The comparative study of adsorption properties of several adsorbents with focus on selective isolation of water-soluble B vitamins (B-2, B, B-6 and B-12) from food products and some pharmaceutical formulations by solid-phase extraction is performed. The adsorption of vitamins was investigated for eleven adsorbents including bare silica, silica modified with polyvinylpyrrolidone, octadecyl-, aminopropyl-, cyanobutyl-functional groups, poly(styrene-divinylbenzene) modified with lactam groups, hypercrosslinked polystyrene, activated carbon and porous microdispersed sintered detonation nanodiamond. Dynamic adsorption capacities of adsorbents for each of the tested vitamins were determined from the dynamic output curves. The highest adsorption capacity was found for HCPS-based sorbents, but complete desorption from these sorbents required harsh conditions. On this reason MSDN was suited better for the preconcentration of water soluble vitamins. [GRAPHICS] .