Apparatus for supercritical fluid extraction having means for removing extraction from collection solvent

• US 5,584,989 A
• Filed: 10/12/1993
• Issued: 12/17/1996
• Est. Priority Date: 07/13/1990
• Status: Expired due to Fees

• Current Assignee: Isco, Inc. (Teledyne Technologies Incorporated)
• Original Assignee: Isco, Inc. (Teledyne Technologies Incorporated)
• Inventors: Jameson, Daniel G.
• Primary Examiner(s): Drodge, Joseph W.
• Application Number:
  US08/134,032
• Time in Patent Office: 1,162 Days
• Field of Search: 210/137, 210/511, 210/634, 210/188, 210/198.2, 210/656, 210/808, 422/103, 422/255, 422/256, 422/260, 422/261, 422/288, 422/69, 422/70, 96/155, 96/174
• US Class Current: 210/137
• CPC Class Codes: B01D 11/0203 with a supercritical fluid
• CPC Class Codes: B01D 11/0407 the supercritical fluid acting as solvent for the solute
• CPC Class Codes: B01D 15/40 using supercritical fluid as mobile phase or eluent
• CPC Class Codes: F04B 15/08 the liquids having low boiling points
• CPC Class Codes: F04B 2205/03 Pressure in the compression chamber
• CPC Class Codes: F04B 2205/05 Pressure after the pump outlet
• CPC Class Codes: F04B 2205/09 Flow through the pump
• CPC Class Codes: F04B 49/065 and making use of computers
• CPC Class Codes: F04B 9/042 the means being cams
• CPC Class Codes: F05B 2230/41 Hardening; Annealing
• CPC Class Codes: F05C 2201/0493 Tin
• CPC Class Codes: F05C 2253/12 Coating
• CPC Class Codes: F16K 15/1823 for ball check valves
• CPC Class Codes: G01F 1/34 by measuring pressure or differential pressure
• CPC Class Codes: G01N 1/34 Purifying; Cleaning processes or apparatus for extracting or separating nucleic acids from biological samples C12N15/1003
• CPC Class Codes: G01N 1/40 Concentrating samples
• CPC Class Codes: G01N 2001/4033 sample concentrated on a cold spot, e.g. condensation or distillation
• CPC Class Codes: G01N 2001/4061 Solvent extraction
• CPC Class Codes: G01N 2030/6013 interfaces to detectors
• CPC Class Codes: G01N 2035/0441 for samples
• CPC Class Codes: G01N 30/02 : Column chromatography
• CPC Class Codes: G01N 30/28 : Control of physical parameters of the fluid carrier
• CPC Class Codes: G21F 5/015 : for storing radioactive sources, e.g. source carriers for irradiation units; Radioisotope containers

Abstract

To collect analyte in a supercritical fluid extraction process, the extractant flows to a collection container under pressure. In one embodiment, the collection container contains collection solvent through which the extractant flows to partition analyte. The extractant adds to the liquid and when the collection solvent-extractant mixture rises to a heating zone, the extractant vaporizes selecively since its vapor pressure is higher than the vapor pressure of the collection solvent. When its pressure exceeds a preset valve pressure it is vented so that extractant continually leaves the collection container. After the extraction is complete, the analyte is concentrated in the collection solvent. In another embodiment, the collection vessel includes a solid material on which the analyte collects. It is removed under pressure by a solvent that is concentrated under pressure.

Claims

1. An apparatus for supercritical fluid extraction comprising:

a supercritical fluid extractor;

at least one container arranged to collect extractant and extraction solvent from said supercritical fluid extractor;

means for pressurizing the at least one container at a predetermined pressure wherein extractant selectively passes into collection solvent in the at least one container; and

means for selectively and substantially continuously removing extraction solvent from said collection solvent in said at least one container based on vapor pressure differential between the extraction and collection solvents.

2. An apparatus for supercritical fluid extraction in accordance with claim 1 further comprising a device for controlling the pressure within the at least one container.

3. An apparatus for supercritical fluid extraction in accordance with claim 2 further comprising separating means for separating fractional evaporated extraction solvent from liquid collection solvent mixed with thereof in the removed solvent by separating liquid and gas phases.

4. An apparatus for supercritical fluid extraction comprising:

a supercritical fluid extractor means;

at least one container arranged to collect extractant and extraction solvent from said extractor means;

means for pressurizing the at least one container at a predetermined pressure wherein extractant selectively passes into collection solvent in the at least one container;

means for selectively and substantially continuously removing extraction solvent from said collection solvent in said at least one container based on vapor pressure differential between the extraction and collection solvent during extraction;

each said at least one container being adapted to communicate with said supercritical fluid extraction means by means of a restrictor; and

each said at least one container having an opening with said opening being closed by a septum means which at least partially seals the container when the container is not in contact with the restrictor.