Chromatographic packings comprising metal oxide/hydroxide reacted with phosphonic acid
AssigneeAluminum Company of America
InventorsLarry F. Wieserman, John W. Novak, Jr., Christine M. Conroy, Karl Wefers
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Abstract
A chromatographic packing material is disclosed comprising a metal oxide/hydroxide particle having chemically bonded to reactive sites on a surface thereof, a monolayer of one or more phosphonic acids. The bond to the metal oxide/hydroxide surface is formed by reaction of the phosphorous-containing group of the phosphonic acid with the metal oxide/hydroxide surface, so that the carbon-containing or non-polar group of the phosphonic acid is oriented away from the metal oxide/hydroxide surface.
Claims23
A chromatographic packing material comprising a monomolecular layer of one or more phosphonic acids chemically bonded to substantially all of the exposed hydroxyl groups on the surface of a particulate metal oxide/hydroxide support material having a particle size range of from about 0.5 to 300 microns;
- a pore diameter range of from about 20 to about 10,000 Angstroms;
- and a pore volume of from about 0.1 to about 2 milliliters/gram.
A chromatographic packing material comprising a monomolecular layer of a mixture of phosphonic acids bonded to a particulate metal oxide/hydroxide support material wherein:
- (a) said mixture of phosphonic acids bonded to said support material comprises from about 1 to about 75 wt. % of the total weight of said packing material and said mixture further comprises:
- (i) from about 2 to about 97% of one or more phosphonic acids having the formula RPO(OH).sub.2 wherein R is a 5-30 carbon saturated or unsaturated aliphatic hydrocarbon or an aromatic hydrocarbon;
- and
- (ii) from about 5 to about 75% of one or more phosphonic acids having the formula R'PO(OH).sub.2 wherein R' is a 1-4 carbon saturated or unsaturated aliphatic hydrocarbon;
- and
- (b) said particulate support material is further characterized by a particle size range of from about 0.5 to about 300 microns, a pore diameter range of from about 20 to about 100,000 Angstroms, and a pore volume of from about 0.1 to about 2 milliliters/gram.
A reverse phase chromatographic packing material comprising:
- (a) a particulate aluminum oxide/hydroxide support material having a particle size range of from about 0.5 to about 300 microns, a pore diameter range of from about 20 to about 100,000 Angstroms, and a pore volume of from about 0.1 to about 2 milliliters/gram:
- and having chemically bonded thereto;
- (b) a monomolecular layer of phosphonic acids comprising a mixture of:
- (i) from about 25 to about 95% of one or more phosphonic acids having the formula RPO(OH).sub.2 wherein R is a 5-30 carbon saturated or unsaturated aliphatic hydrocarbon or an aromatic hydrocarbon;
- and
- (ii) from about 5 to about 75% of one or more phosphonic acids having the formula R'PO(OH).sub.2 wherein R' is a 1-4 carbon saturated or unsaturated aliphatic hydrocarbon;
- whereby a reverse phase chromatographic packing material is formed characterized by good pH stability and high efficiency.
The reverse phase chromatographic column exhibiting good pH stability and high efficiency comprising a column filled with particulate packing material comprising a monomolecular layer of phosphonic acids comprising a mixture of:
- (a) from about 25 to about 95% of one or more phosphonic acids having the formula RPO(OH).sub.2 wherein R is a 5-30 carbon saturated or unsaturated aliphatic hydrocarbon or an aromatic hydrocarbon;
- and
- (b) from about 5 to about 75% of one or more phosphonic acids having the formula R'PO(OH)2 wherein R' is a 1-4 carbon saturated or unsaturated aliphatic hydrocarbon;
- said phosphonic acids being bonded to a particulate aluminum oxide/hydroxide support material having a particle size range of from about 0.5 to about 300 microns, a pore diameter range of from about 20 to about 10,000 Angstroms, and a pore volume of from about 0.1 to about 2 milliliters/gram.
A method of making a chromatographic packing material characterized by good pH stability and high efficiency comprising:
- (a) reacting with a particulate metal oxide/hydroxide support material, having a particle size range of from about 0.5 to about 300 microns, one or more phosphonic acids having the formula RPO(OH).sub.2 wherein R is a 5-30 carbon saturated or unsaturated aliphatic hydrocarbon or an aromatic hydrocarbon to form a monomolecular layer of said one or more phosphonic acids on the surface of said particulate support material;
- and
- (b) further reacting said particulate support material with one or more phosphonic acids having the formula R'PO(OH).sub.2 wherein R' is a 1-4 carbon saturated or unsaturated aliphatic hydrocarbon in a quantity sufficient to form chemical bonds with all remaining reactive hydroxyl sites on said support material.
Dependencies are inferred from the claim text.