Process of removing and concentrating desired molecules from solutions

Abstract

A method is disclosed for the quantitative removal and concentration of desired molecules or ions, such as gases, anions and amino acids, from a source solution which may contain larger concentrations of other molecules. The method comprises bringing the source solution into contact with a solid cation-ligand-matrix consisting of a cation complexed to a ligand molecule covalently bonded to a matrix consisting of an organic spacer bonded to a solid inorganic support through a silicon atom. The cation has an affinity for the desired molecules to form a complex between the desired molecules and the cation portion of the solid cation-ligand-matrix at binding sites initially held by H.sub.2 O or other weakly coordinated ligands or via ion pairing. The desired molecule complex is broken releasing either the desired molecules or desired molecules complexed with the cation by contacting the solid cation-ligand-matrix-desired molecule complex with a much smaller volume of a receiving solution in which said desired molecules are soluble. The concentrated ions or molecules thus removed may be analyzed and/or recovered by known methods. The process is useful in measuring the concentrations of molecules originally present at parts per billion levels; in the removal of low levels of toxic molecules such as ammonia or anions such as chromate from potable and saline water; in the preparation of ultrapure salts and gases; and in the recovery of valuable molecules present in low concentrations as in the separation of amino acids, etc.