Method for fluid sampling using electrically controlled droplets

• US 7,454,988 B2
• Filed: 02/09/2006
• Issued: 11/25/2008
• Est. Priority Date: 02/10/2005
• Status: Active Grant

• Current Assignee: Applied Biosystems LLC (Thermo Fisher Scientific Incorporated)
• Original Assignee: Applera Corporation (Thermo Fisher Scientific Incorporated)
• Inventors: Tan, Roy H.
• Primary Examiner(s): Rogers; David A.
• Application Number:
  US11/351,706
• Publication Number:
  US 20060186048A1
• Time in Patent Office: 1,020 Days
• Field of Search: 73/232.2, 73/233, 73/233.4, 73/233.5, 73/280.1, 73 2804- 2806, 73 3101- 3103, 73/310.7, 738/632.1, 738/632.2, 738/632.3, 738/632.4, 738/634.1, 738/648.1, 738/647.1, 204/600, 204/643, 204/648, 422/83, 422/84, 422/88, 422/89, 422/94
• US Class Current: 73/863.21
• CPC Class Codes: G01N 1/4055 by solubility techniques
• CPC Class Codes: G01N 2001/4066 using difference of solubility between liquid and gas, e.g. bubbling, scrubbing or sparging
• CPC Class Codes: G01N 2030/065 using different phases to separate parts of sample
• CPC Class Codes: G01N 2030/143 selective absorption
• CPC Class Codes: G01N 30/06 Preparation
• CPC Class Codes: G01N 30/14 by elimination of some components
• CPC Class Codes: Y10T 436/25875 Gaseous sample or with change of physical state

Abstract

The present disclosure relates to a method for sampling a fluid, such as air. As fluid flows through a device, a scrubbing liquid is positioned in a pattern to contact the fluid and constituents in the fluid are transferred to in the liquid.

Claims

1. A method for sampling a fluid, the method comprising:

providing a sampling fluid in a directional stream;

positioning a scrubbing liquid in a pattern to intercept the sampling fluid;

contacting the sampling fluid with the scrubbing liquid to remove at least one constituent from the sampling fluid;

collecting the scrubbing liquid to collect the constituent; and

analyzing the scrubbing liquid for the presence of the constituent,

wherein the scrubbing liquid is positioned in the pattern by electrical control.

2. The method of claim 1, wherein the sampling fluid is a gas.

3. The method of claim 2, wherein the gas is air.

4. The method of claim 1, wherein the pattern comprises of individually controllable droplets.

5. The method of claim 4, wherein the sampling fluid is a gas, and wherein the gas is air or human respiration.

6. The method of claim 4, wherein the droplets are controlled by electrowetting.

7. The method of claim 6, wherein the droplets are controlled by electrowetting on a dielectric.

8. The method of claim 7, wherein the electrowetting on a dielectric is optically activated.

9. The method of claim 7, further comprising:

providing a gas sampling device, wherein the device comprises;

a first surface;

a second surface, parallel and proximate to the first surface;

a volume at least partially defined by said first and second surfaces;

a source chamber suitable for containing a liquid, said source chamber being fluidly connected to said volume;

a collection chamber suitable for containing a liquid, said collection chamber being fluidly connected to said volume; and

a passage allowing a flow of gas through said volume; and

moving liquid droplets from the source chamber to the collection chamber.

10. The method of claim 9, wherein analyzing comprises providing an analytical device for performing at least one of colorimetric, fluorescent, chemiluminescent, and chromatographic analysis.

11. The method of claim 9, further comprising:

providing a plurality of air sampling devices, wherein the devices are positioned in a parallel stack or in series.

12. The method of claim 9, wherein the collection chamber is fluidly connected to a mass spectrometer, a liquid chromatograph, or a gas chromatograph.

13. The method of claim 1, wherein the pattern comprises of individually controllable structures.

14. The method of claim 13, wherein the scrubbing liquid comprises ferrofluids.

15. The method of claim 14, wherein the sampling fluid is a gas, and wherein the gas is air or human respiration.

16. The method of claim 14, further comprising:

providing a gas sampling device, wherein the device comprises;

a first surface;

a second surface, parallel and proximate to the first surface;

a cavity at least partially defined by said first and second surfaces;

a plurality of magnetizable structures, each of which is shaped so as to provide two ends, wherein each end functions as one pole of a dipole when the ferrofluid is magnetized, and wherein the ends oppose each other across said cavity;

a power source configured to provide an electric current to the plurality of magnetizable structures in a manner that generates a magnetic field across said cavity; and

a passage fluidly coupled with said cavity.

17. The method of claim 16, further comprising optically activating the ferrofluid structures.

18. The method of claim 16, wherein the ferrofluid is hydrophilic or hydrophobic.

19. The method of claim 16, wherein analyzing comprises providing an analytical device for performing at least one of colorimetric, fluorescent, chemiluminescent, and chromatographic analysis.

20. The method of claim 16, wherein the collection chamber is fluidly connected to a mass spectrometer, a liquid chromatograph, or a gas chromatograph.

21. A method for sampling gases, the method comprising:

providing a gas in a directional stream;

positioning a scrubbing liquid in a pattern droplets to intercept the gas;

contacting the gas with the scrubbing liquid to remove at least one constituent from the gas;

collecting the scrubbing liquid to collect the constituent; and

analyzing the scrubbing liquid for the presence of the constituent,

wherein the scrubbing liquid is positioned in the pattern of droplets by electrowetting on a dielectric.

22. A method for sampling gases, the method comprising:

providing a gas in a directional stream;

positioning a scrubbing liquid in a pattern of ferrofluid structures to intercept the gas;

contacting the gas with the scrubbing liquid to remove at least one constituent from the gas;

collecting the scrubbing liquid to collect the constituent; and

analyzing the scrubbing liquid for the presence of the constituent,

wherein the scrubbing liquid is positioned in the pattern of ferrofluid structures by applying a magnetic field to the ferrofluid.