Covalently Immobilized Fluorinated Carboxylic Acid Stationary Phase For Liquid Chromatography

• US 20090043042A1
• Filed: 08/06/2008
• Published: 02/12/2009
• Est. Priority Date: 08/06/2007
• Status: Active Grant

• Current Assignee: National Institute of Standards and Technology (Government of the United States of America), THE GOVERNMENT OF THE UNITED STATES OF AMERICA, AS REPRESENTED BY THE SECRETARY OF COMMERCE
• Original Assignee: National Institute of Standards and Technology (Government of the United States of America), THE GOVERNMENT OF THE UNITED STATES OF AMERICA, AS REPRESENTED BY THE SECRETARY OF COMMERCE
• Inventors: Sander, Lane C., Lippa, Katrice A., Rimmer, Catherine A.
• Granted Patent: US 7,794,837 B2
• Time in Patent Office: Days
• US Class Current: 524/588
• CPC Class Codes: B01D 15/325 Reversed phase
• CPC Class Codes: B01J 20/103 comprising silica
• CPC Class Codes: B01J 20/282 Porous sorbents ion exchange B01J39/00 - B01J41/00
• CPC Class Codes: B01J 20/287 Non-polar phases; Reversed phases
• CPC Class Codes: B01J 20/3204 Inorganic carriers, supports or substrates
• CPC Class Codes: B01J 20/3219 involving a particular spacer or linking group, e.g. for attaching an active group
• CPC Class Codes: B01J 20/3259 comprising at least two different types of heteroatoms selected from nitrogen, oxygen or sulfur with at least one silicon atom
• CPC Class Codes: Y10T 428/2991 Coated
• CPC Class Codes: Y10T 428/2993 Silicic or refractory material containing [e.g., tungsten oxide, glass, cement, etc.]
• CPC Class Codes: Y10T 428/2995 Silane, siloxane or silicone coating

Abstract

A stationary phase for a liquid chromatograph and process for making is provided. The stationary phase material may have a modified base substrate and a fluorinated carboxylic acid covalently bonded thereto through an amide or ester bond. The stationary phase may have a substantially consistent shape selectivity characteristic with an α_TBN/BaP of less than 1 within a temperature range of at least 10-70° C. Advantageously, a fluorinated stationary phase has a shape selectivity characteristic exhibited with an α_TBN/BaP of less than 1 with a mobile phase having up to at least 30% water. A process for making the stationary involves mixing a substrate material or fluorinated carboxylic acid with a reactive alkylsilane linker and at least one organic solvent to form a first solution. The other of the substrate material or fluorinated carboxylic acid is then added to the first solution, or to a product separated from the first solution, to form a second solution. The second solution is reacted to form the stationary phase.

Claims

1. A process for making a stationary phase for a reversed phase liquid chromatograph comprising:

mixing a substrate material or fluorinated carboxylic acid with a reactive alkylsilane linker and at least one organic solvent to form a first solution;

adding the other of said substrate material or said fluorinated carboxylic acid to said first solution or separated product therefrom to form a second solution; and

reacting said second solution forming said stationary phase.

2. The process of claim 1 wherein said mixing step is comprised of mixing said substrate material with said reactive alkylsilane linker and said at least one organic solvent, said mixing step being followed by a step of separating a functionalized substrate from said first solution, said separated product from said first solution being said functionalized substrate, said adding step comprising adding said fluorinated carboxylic acid and at least one organic solvent to said functionalized substrate forming said second solution.

3. The process of claim 1 wherein said mixing step is comprised of mixing said fluorinated carboxylic acid with said reactive alkylsilane linker and said at least one organic solvent, said adding step comprising adding said substrate material to said first solution forming said second solution.

4. The process of claim 1 wherein said second solution is heated to at least 25°

C.

5. The process of claim 1 wherein said substrate material has at least one synthetic organic polymer or a constituent selected from the group consisting of comprised of silica, alumina, titania, zirconia, hafnia, and combinations thereof.

6. The process of claim 1 wherein said substrate material has silica.

7. The process of claim 1 wherein said reactive alkylsilane linker has at least one constituent selected from the group consisting of comprised of 3-aminopropyltriethoxysilane, 3-aminopropylmethyldiethoxysilane, 3-aminopropyldimethylethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropylmethyldimethoxysilane, 3-aminopropyldimethylmethoxysilane, 3-aminopropyltrichlorosilane, 3-aminopropylmethyldichlorsilane, 3-aminopropyldimethylchloroxysilane, 4-aminobutyltriethoxysilane, 4-aminobutylmethyldiethoxysilane, 4-aminobutyldimethylethoxysilane, 4-aminobutyltrimethoxysilane, 4-aminobutylmethyldimethoxysilane, 4-aminobutyldimethylmethoxysilane, 4-aminobutyltrichlorosilane, 4-aminobutylmethyldichlorsilane, 4-aminobutyldimethylchloroxysilane, glycidoxy-t-butyldimethylsilane, (3-glycidoxypropyl)bis(trimethylsiloxy)-methylsilane, (3-glycidoxypropyl)dimethylethoxysilane, (3-glycidoxypropyl)methyldiethoxysilane, (3-glycidoxypropyl)methyldimethoxysilane, (3-glycidoxypropyl)triethoxysilane, (3-glycidoxypropyl)trimethoxysilane, other amino- or epoxide-terminated reactive silanes, and combinations thereof.

8. The process of claim 1 wherein said adding step further comprises adding at least one catalyst to form said first or second solution.

9. The process of claim 8 wherein said at least one catalyst has a catalyst selected from the group consisting of diisopropylcarbodiimide, dicyclohexylcarbodiimide, ethyl(dimethyl aminopropyl)carbodiimide or other relevant alkylcarbodiimides, N-hydroxybenzotriazole or N-hydroxysuccinimide.

10. The stationary phase formed by the process of claim 1.

11. The process of claim 1 wherein said stationary phase has fluorinated carboxylic acid covalently bonded to said substrate material.

12. A stationary phase material for a liquid chromatograph comprising:

a modified base substrate; and

fluorinated carboxylic acid covalently bonded to said modified base substrate through an amide or ester bond.

13. The stationary phase material of claim 12 wherein said modified base substrate is an alkylsilane-modified base substrate.

14. The stationary phase material of claim 12 wherein said fluorinated carboxylic acid has at least 7 perfluorinated carbon atoms.

15. The stationary phase material of claim 12 wherein said fluorinated carboxylic acid has about 17 perfluorinated carbon atoms.

16. A stationary phase material for a liquid chromatograph having a substantially consistent shape selectivity characteristic with an α

_TBN/BaP of less than 1 within a temperature range of at least 10-70°

C.

17. The stationary phase material of claim 16 having fluorinated carboxylic acid covalently bonded to a modified base substrate.

18. The stationary phase material of claim 17 wherein said fluorinated carboxylic acid is covalently bonded to said modified base substrate through an amide or ester bond.

19. A fluorinated stationary phase material for a liquid chromatograph having shape selectivity characteristics exhibited with an α

_TBN/BaP of less than 1 with a mobile phase having up to at least 30% water.

20. The fluorinated stationary phase of claim 19 having fluorinated carboxylic acid covalently bonded to a modified base substrate.