Microwave-assisted chromatography preparation

• US 7,812,291 B2
• Filed: 07/12/2006
• Issued: 10/12/2010
• Est. Priority Date: 08/20/2004
• Status: Expired due to Fees

• Current Assignee: CEM Global LLC
• Original Assignee: CEM Global LLC
• Inventors: Collins, Michael John Sr., Hargett, Wyatt Price Jr., Collins, Michael John Jr., Thomas, James Edward, Barnhardt, E. Keller
• Primary Examiner(s): ROBINSON, DANIEL LEON
• Application Number:
  US11/456,997
• Publication Number:
  US 20060261058A1
• Time in Patent Office: 1,553 Days
• Field of Search: 219/679, 219/678, 219/680, 219/681, 219/682, 219/683, 219/684, 219/685, 210/656, 210/657, 210/658, 210/659, 961/01, 961/02, 961/03, 961/04, 961/05, 961/06, 961/07
• US Class Current: 219/679
• 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 sample preparation apparatus for flash chromatography, comprising:

a source of microwave radiation for applying microwave energy;

a microwave cavity in wave communication with said source;

a microwave transparent vessel in said cavity holding chromatography media; and

a gas pump in gas communication with said vessel in said cavity for moving gases through said vessel during the application of microwaves to the vessel and chromatography media to facilitate evaporation of solvent from said chromatography media.

2. The apparatus according to claim 1, wherein said microwave source is selected from the group consisting of magnetrons, klystrons, and solid state devices.

3. The apparatus according to claim 1 further comprising a microprocessor for controlling said microwave source.

4. The apparatus according to claim 1, comprising a waveguide between said source and said cavity.

5. The apparatus according to claim 1, wherein said vessel comprises a chamber portion and a top portion.

6. The apparatus according to claim 1, wherein said microwave transparent vessel is selected from the group consisting of glass, polymers and quartz.

7. The apparatus according to claim 5, comprising a gas inlet about said top portion of said vessel for allowing make-up gas into said vessel.

8. The apparatus according to claim 7, wherein said gas inlet comprises tubing projecting into said vessel.

9. The apparatus according to claim 1, comprising a gas outlet about said vessel for allowing solvent to evacuate said vessel.

10. The apparatus according to claim 9, wherein said gas outlet communicates with said gas pump.

11. The apparatus according to claim 1, comprising chemical resistant tubing between said vessel and said gas pump.

12. The apparatus according to claim 3 wherein said microprocessor controls said microwave source and said gas pump.

13. The apparatus according to claim 7, wherein said gas inlet is in physical communication with said gas pump;

and

said gas pump maintains pressure in said vessel to facilitate the evaporation of the solvent from the chromatography media.

14. The apparatus according to claim 1, wherein said gas pump comprises a vacuum pump.

15. A microwave-assisted chromatography sample preparation instrument, comprising:

a microwave source;

means for controlling the application of microwave energy from said microwave source;

a microwave transparent vessel in wave communication with said microwave source for evaporating solvent from a solvent-containing composition;

a gas inlet tube about said vessel for allowing make-up gas into said vessel;

a gas exit tube about said vessel for allowing solvent to evacuate said vessel; and

a gas pump in physical communication with said vessel for creating a gas flow through said vessel to evaporate solvent from the solvent-containing composition in the vessel and from the vessel during and between applications of microwave energy.

16. The instrument according to claim 15, wherein said microwave source is selected from the group consisting of magnetrons, klystrons, and solid state devices.

17. The instrument according to claim 15, wherein means for controlling the application of microwave energy comprises a microprocessor in signal communication with said source for controlling the application of microwave energy from said microwave source to said sample.

18. The instrument according to claim 17, comprising means for pulsing the microwave energy to avoid overheating the sample.

19. The instrument according to claim 15, comprising a waveguide between said source and said vessel.

20. The instrument according to claim 15 wherein said microwave transparent vessel is selected from the group consisting of glass, polymers, and quartz.

21. The instrument according to claim 15, wherein said gas outlet communicates with said gas pump using chemical resistant tubing.

22. The instrument according to claim 15 wherein said microprocessor simultaneously controls said microwave source and said gas pump.

23. The instrument according to claim 15, further comprising a temperature sensor for measuring the temperature of the sample.

24. The instrument according to claim 23, wherein said temperature sensor is selected from the group consisting of infrared detectors, ultraviolet detectors, and fiber optic sensors.

25. The instrument according to claim 23, comprising a temperature sensor in signal communication with a computer microprocessor.

26. The instrument according to claim 25, wherein said microprocessor is in signal communication with said source and with said temperature sensor for thereby moderating the application of microwaves from the source based upon the monitored temperature.