Inorganic ion pairs in physiology: significance and quantitation

1. Body fluids contain ion pairs such as NaC10, CaCl+, CaHCO+3 and MgSO04. 2. Ion pairs must often be considered in the quantitation of acid-base, solubility, Donnan and other equilibria. 3. Fluxes of ion pairs, such as NaCO-3 and perhaps NaSO-4 and NaCl0, may sometimes contribute significantly to total ion fluxes across cell membranes. 4. Dissociation constants for ion pairs are discussed, but values appropriate to body fluids are often uncertain.