Selective transport of aldehydes across an anion-exchange membrane via the formation of bisulfite adducts

Organic nonelectrolytes can be selectively transported through an ion-exchange membrane if they specifically converted to electrolytes in the membrane. Aldehydes react with bisulfite to form (HASA), which are the conjugate bases of strong acids. Aldehydes are shown be transported efficiently across an anion-exchange membrane via the coupled counter-transport HMSA ion with hydroxide ion and the relay of an aldehyde from one membrane-bound bisulfite to another. Permeation rates are in the order of formaldehyde > acetaldehyde > acetone; this parallels the relative order of the stability constants for formation of the respective with bisulfite ion. Aldehydes can be separated readily from other organic solutes by this .