MICROWAVE-ASSISTED CHROMATOGRAPHY PREPARATION

• US 20080116363A1
• Filed: 01/28/2008
• Published: 05/22/2008
• Est. Priority Date: 08/20/2004
• Status: Active Grant

• Current Assignee: CEM Global LLC
• Original Assignee: CEM Global LLC
• Inventors: COLLINS, MICHAEL, BARNHARDT, E., HARGETT, WYATT, THOMAS, JAMES
• Granted Patent: US 7,939,785 B2
• Time in Patent Office: Days
• US Class Current: 250/251
• CPC Class Codes: F26B 21/14 using gases or vapours other than air or steam , e.g. inert gases
• CPC Class Codes: F26B 3/347 Electromagnetic heating, e.g. induction heating or heating using microwave energy
• CPC Class Codes: F26B 5/048 in combination with heat developed by electro-magnetic means, e.g. microwave energy
• CPC Class Codes: F26B 9/003 Small self-contained devices, e.g. portable
• CPC Class Codes: G01N 1/44 Sample treatment involving radiation, e.g. heat
• CPC Class Codes: G01N 2030/567 coating
• CPC Class Codes: G01N 30/06 Preparation
• CPC Class Codes: H05B 6/806 for laboratory use

Abstract

An instrument and associated method are disclosed for preparing samples for column chromatography. The method includes the steps of applying microwave energy to a sample composition containing at least one solvent to encourage a chemical reaction and generate desired products, thereafter mixing an absorbent media with the sample to absorb the solvent, the media being compatible with liquid chromatography that will separate the expected products, being chemically inert to the expected products, and being added in an amount sufficient to provide a substantially dry mixture of the media and the sample, but less than an amount that overly broadens the resolution of the sample during liquid chromatography, thereafter applying microwave energy to the dry mixture of the media and the sample to thereby encourage the solvent to evaporate under the influence of the microwave energy, and thereafter adding the dry mixture of the media and the remaining sample to a liquid chromatography column and separating the components of the remaining sample for identification and purification purposes.

Claims

1. A method of preparing samples for column chromatography comprising:

applying microwave energy to a sample composition containing at least one solvent to encourage a chemical reaction and generate desired products;

thereafter mixing an absorbent media with the sample to absorb the solvent, the media being compatible with liquid chromatography that will separate the expected products, being chemically inert to the expected products, and being added in an amount sufficient to provide a substantially dry mixture of the media and the sample, but less than an amount that overly broadens the resolution of the sample during liquid chromatography;

thereafter applying microwave energy to the dry mixture of the media and the sample to thereby encourage the solvent to evaporate under the influence of the microwave energy; and

thereafter adding the dry mixture of the media and the remaining sample to a liquid chromatography column and separating the components of the remaining sample for identification and purification purposes.

2. A sample preparation method according to claim 1 comprising:

carrying out the microwave assisted reaction in a microwave transparent vessel;

mixing the absorbent media with the sample in the same vessel to produce the dry mixture in the vessel; and

applying the microwave energy to the dry mixture to remove the solvent while the dry mixture remains in the same vessel.

3. The method as in claim 2 comprising computer microprocessor control of at least the steps of carrying out the reaction and applying microwave energy to the sample.

4. The method as in claim 3 wherein the step of carrying out a reaction comprises using pulsed microwave energy controlled by the microprocessor.

5. The method as in claim 1 wherein the sample is actively cooled using a cooling fan.

6. The method as in claim 1 wherein the absorbent media is selected from the group consisting of silica, sand, alumina, and diatomaceous earth.

7. The method as in claim 6 wherein the absorbent media comprises a volume of media about equal to the volume of solvent.

8. A method of preparing samples for column chromatography, comprising:

applying microwave energy to a sample composition containing at least one solvent to encourage a chemical reaction and generate desired products;

mixing a scavenging composition with the sample to remove contaminants and excess reagents;

mixing an absorbent media with the sample to absorb the solvent, the media being compatible with liquid chromatography that will separate the expected products, being chemically inert to the expected products, and being added in an amount sufficient to provide a substantially dry mixture of the media and the sample, but less than an amount that overly broadens the resolution of the sample during liquid chromatography;

thereafter applying microwave energy to the dry mixture of the media and the sample to thereby encourage the solvent to evaporate under the influence of the microwave energy; and

thereafter adding the dry mixture of the media and the remaining sample to a liquid chromatography column and separating the components of the remaining sample for identification and purification purposes.

9. The method of claim 8 wherein the step of adding a scavenging composition to the sample comprises electrophile scavenging compositions, nucleophile scavenging compositions, base scavenging compositions, and acid scavenging compositions.

10. The method of claim 8 further comprising the step of applying microwave energy to the scavenger-sample mixture to accelerate the scavenging removal of contaminants and excess reagents prior to the step of mixing the absorbent media with the sample.

11. The method of claim 8 comprising adding a coupling reagent to the sample to facilitate the conversion of reactants to products.

12. The method of claim 8 comprising adding a catalyst reagent to the sample to accelerate the rate of the reaction.

13. The method of claim 8 wherein column chromatography comprises the technique of flash chromatography.

14. A method of dry-loading samples for column chromatography, comprising:

adding an amount of chromatography media to a vessel holding a sample, the sample being dissolved in a solvent;

evaporating the solvent using microwave energy, leaving dried chromatography media containing the sample; and

dry-loading the dried chromatography media containing the sample onto a separation chromatography column for identification and purification of the sample components.

15. The method according to claim 14 wherein the step of adding an amount of chromatography media to a vessel comprises an amount about equal to the amount of solvent.

16. The method according to claim 14 wherein the step of adding an amount of chromatography media to the vessel comprises manually adding the chromatography media to the vessel.

17. The method according to claim 14 wherein the step of loading the dried chromatography media containing the sample onto a separation chromatography column comprises manually loading the chromatography media onto the column.

18. The method according to claim 14 wherein the step of adding an amount of chromatography media to the vessel comprises a microprocessor in electronic control of adding an amount of chromatography media to the vessel.

19. The method according to claim 14 wherein the step of evaporating the solvent using microwave energy comprises a microprocessor in electronic control of the microwave energy.

20. The method according to claim 19 wherein the step of evaporating the solvent using microwave energy comprises a microprocessor in electronic control of pulsing the microwave energy.

21. The method according to claim 14 wherein the step of dry-loading the dried chromatography media containing the sample onto a separation chromatography column comprises a computer microprocessor in electronic control of loading the dried chromatography media containing the sample onto a separation chromatography column for identification and purification of the sample components.