Distiction of an organic non-electrolyte by a specific reaction and a design of a novel transport system with ion-exchange membranes.

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The distinction of an organic solute and its selective transport can be carried out by the combination of a membrane transport and a specific reaction of the organic solute with an inorganic ion.Aldehydes and sugars were selectively transported across an anionexchange membrane via their adduct-formation reactions with bisulfite ion, the complex-formation reaction of sugars with borate ion, and their aciddissociation reactions. Aldehydes react with bisulfite ion to form hydroxyalkanesulfonates(HASA), which are the conjugate bases of a strong acid, and were able to be transported efficiently across an anion-exchange membrane on the basis of the relay of an aldehyde from a bisulfite ion to the other, which were fixed on the membrane. Aldehydes were not transported across the anion-exchange membrane of chloride-ion type. The aldehyde transport was enhanced significantly by the ion-exchange reaction of HASA ion in the membrane with bisulfite ion in the receiving phase. Aldehydes were transported efficiently against the concentration gradient when the bisulfite ion concentration was high. On the basis of these results, the transport mechanism and the transport equation were discussed. The flux was dependent on the aldehyde concentration in the source phase solution and the existence of a limiting value was predicted by the equation and confirmed experimentally. It was possible to separate an aldehyde from another aldehyde depending on their stability constants of their adducts with bisulfite ion. Sugars were also actively transported and were separated from each other on the same basis.Organic solutes can be selectively transported or concentrated via this method in the membrane transport system by specific reactions of the organic solutes with inorganic ions.