Automated supercritical fluid extraction method and apparatus

• US 5,866,004 A
• Filed: 09/08/1995
• Issued: 02/02/1999
• Est. Priority Date: 10/16/1992
• Status: Expired due to Fees

• Current Assignee: Teledyne Isco, Inc. (Thermo Fisher Scientific Incorporated)
• Original Assignee: Suprex Corp (Teledyne Technologies Incorporated)
• Inventors: Williams, Glen P., Bauer, Paul A. Jr., Kato, Kenneth J., Houck, Raymond K., Koebler, Douglas J., Parks, Robert D.
• Primary Examiner(s): Drodge, Joseph W.
• Application Number:
  US08/524,916
• Time in Patent Office: 1,243 Days
• Field of Search: 210/634, 210/181, 210/136, 210/137, 210/656, 210/511, 210/198.2, 210/321.6, 210/143, 210/739, 210/180, 422/63, 422/64, 422/65, 422/69, 422/70, 422/101, 422/102, 436/178
• US Class Current: 210/634
• CPC Class Codes: B01D 11/0203 with a supercritical fluid
• 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 2001/4061 Solvent extraction
• CPC Class Codes: G01N 2030/062 extracting sample from raw material
• CPC Class Codes: G01N 33/24 Earth materials G01N33/42 takes precedence
• CPC Class Codes: Y10T 436/255 including use of a solid sorbent, semipermeable membrane, or liquid extraction

Abstract

A supercritical fluid extraction (SFE) system. The SFE system includes a mechanism for providing supercritical fluid for extracting analyte from a sample. The SFE system also includes an extraction vessel and a mechanism for moving the extraction vessel into fluidic communication with the SFE system so that supercritical fluid can flow through the extraction vessel and extract analyte from the sample. Preferably, the SFE system is additionally comprised of a mechanism for holding a plurality of extraction vessels and an extraction chamber assembly. In this design, the moving mechanism selectively moves an extraction vessel from the holding mechanism into the extraction chamber in fluidic communication with the SFE system. Preferably, the SFE system further includes a computer for controlling the functions of the SFE system. The computer, for instance, could automatically and sequentially control the supercritical fluid extractions of the samples within the holding mechanism. The SFE system preferably includes a mechanism for collecting analyte from the fluid with analyte. The collecting mechanism is in fluid communication with extraction chamber assembly and preferably includes a restrictor for controlling the flow of fluid with analyte to the collecting mechanism. The restrictor converts the fluid with analyte from a first supercritical pressure to a second pressure which is less than the first supercritical pressure.

Claims

1. A supercritical fluid extraction system comprising:

means for providing supercritical fluid for extracting analyte from a sample;

means for holding a plurality of extraction vessels having samples therein;

an extraction chamber assembly;

means for selectively moving an extraction vessel from the holding means into the extraction chamber assembly so supercritical fluid can flow through the extraction vessel and extract analyte from the sample and microprocessor means for individually programming each vessel with extraction process parameters.

2. A system as described in claim 1 wherein the microprocessor means includes a computer for automatically controlling the providing means, the holding means, the moving means and the extraction chamber assembly such that the analyte is extracted and collected at a desired pressure and a desired temperature with the desired supercritical fluid at a desired flow rate and a desired time, said computer in communication therewith.

3. A supercritical fluid extraction system as described in claim 2 including means for collecting analyte from the fluid with analyte, said collecting means in fluidic communication with the extraction chamber assembly.

4. A system as described in claim 3 wherein the extracting or collecting means includes a restrictor for controlling flow of fluid with analyte from a selected extraction vessel, said restrictor converting the fluid with analyte from a first supercritical pressure to a second pressure, said second pressure less than said first supercritical pressure.

5. A system as described in claim 4 including means for providing a modifier to the supercritical fluid, said modifier providing means in fluidic communication with said means for providing supercritical fluid.

6. A system as described in claim 5 wherein the collecting means includes a collection trap in which analyte is collected from the fluid and means for providing desorbing solvent to the collection trap which dissolves analyte therein.

7. A system as described in claim 6 including means for controlling flow of the fluid from the providing means to the extraction vessel and to the collecting means such that any leaks and plugs can be detected.

8. A system as described in claim 7 wherein the supercritical fluid providing means comprises a pumping system having an output from which supercritical fluid at a desired pressure and flowrate passes;

a source tank of supercritical fluid, said source tank in fluidic communication with the output, said pumping means having at least one variable speed piston which pressurizes the fluid, the speed of the piston at a given time corresponding to the pressure and flowrate of the fluid which passes from the output at the given time; and

microprocessor control means for controlling the pumping means such that the pressure and flowrate of the supercritical fluid provided by the output is maintained at a desired pressure and flowrate.

9. A system as described in claim 8 wherein the restrictor is an automated variable restrictor.

10. A system as described in claim 9 including a vent valve for venting fluid from the extraction vessel, said vent valve located downstream of said extraction vessel and in fluidic communication with said extraction vessel, said vent valve having a first path and a second path.

11. A system as described in claim 10 including plumbing which fluidically connects the supercritical providing means, the modifier providing means, the extraction chamber assembly, the moving means, the collection means and to the exit valve so a desired fluid can flow therebetween;

and including means for flushing the plumbing, the moving means, the vent valve, and the collection means to cleanse the same.

12. A system as described in claim 11 wherein the moving means includes a mechanism for clamping an extraction vessel within the extraction chamber assembly such that the extraction vessel is disposed in fluidic communication between the supercritical fluid providing means and the collecting means;

and means for presenting an extraction vessel from the holding means to the clamping mechanism so that the clamping mechanism can clamp an extraction vessel such that the extraction vessel is disposed between the supercritical fluid providing means and the collecting means, said presenting means disposed adjacent to said clamping mechanism.

13. A system as described in claim 12 wherein the holding means includes a carousel within which the plurality of extraction vessels are held, and the presenting means includes a rotary table in contact with the carousel for turning the carousel to selectively present the extraction vessels to the clamping mechanism.

14. A system as described in claim 13 wherein the clamping mechanism includes a plunger in fluidic communication with the means for providing supercritical fluid;

and means for driving the plunger such that an extraction vessel presented to the plunger by the presenting means can be pushed from the carousel by the plunger into the extraction chamber assembly.

15. A system as described in claim 14 including means for sensing when a selected extraction vessel is in proper engagement within the extraction chamber assembly, said sensing means in electronic communication with the means for driving the plunger.

16. A system as described in claim 15 wherein the extraction chamber assembly includes means for heating the extraction vessel within the extraction chamber assembly, said heating element in thermal communication with an extraction vessel in said chamber assembly.

17. A system as described in claim 16 wherein the plunger or extraction chamber inlet includes means for preheating the supercritical fluid as it flows therethrough.

18. A system as described in claim 17 wherein the extraction vessels are adapted to withstand the pressure of the supercritical fluid.

19. A system as described in claim 18 wherein the holding means comprises means for cooling the extraction vessels within the holding means, said cooling means in thermal communication with the holding means.

20. A system as described in claim 19 wherein the extraction chamber assembly includes means for providing ultrasonic energy to an extraction vessel within the extraction chamber assembly, said ultrasonic means in communication with an extraction vessel within the extraction chamber assembly.

21. A system as described in claim 20 wherein the extraction vessel is comprised of:

a container having a chamber, a first end having a first opening in fluidic communication with the chamber and a second end having a second opening in fluid communication with the chamber;

a first check valve disposed on the first end of the container for selectively sealing the first opening from the chamber; and

a second check valve disposed on the second end of the container for selectively sealing the second opening from the chamber.

22. A system as described in claim 21 wherein each of the check valves is comprised of a seal portion and a spring portion in contact with the seal portion for biasing the seal portion against the respective opening.

23. A system as described in claim 22 wherein the controlling means comprises a plurality of valves for controlling the flow of fluid therethrough, said controlling means selectively controlling the valves and monitoring flow of the fluid through the valves in order to detect and identify leaks and plugs.

24. A system as described in claim 23 wherein the collecting means includes means for heating the collection trap, said heating means in thermal communication with the collection trap;

and means for cooling the collection trap, said means in thermal communication with the collection trap.

25. A system as described in claim 24 wherein the collection means includes at least a first vial in fluidic communication with the collection trap to which analyte dissolved in the desorbing fluid flows.

26. A system as described in claim 25 wherein the collection means includes a cooling unit which maintains the vial at a desired temperature, said cooling unit disposed adjacent to and in thermal communication with the vial.

27. A system as described in claim 26 wherein the collection means includes a fraction collector carousel in which the first vial and at least a second vial, said fraction collection carousel in communication with the computer which controls the position of the fraction collection carousel so a desired vial is positioned to receive desorbing fluid with dissolved analyte at a desired time, said cooling unit maintaining the fraction collection carousel at a desired temperature.

28. A system as described in claim 27 including means for removing water from the supercritical fluid with analyte, said water removing means in fluidic communication with the extraction chamber assembly.

29. A system as described in claim 28 wherein the water removing means includes an absorbent vessel in fluidic communication with the extraction vessel, said absorbent vessel having a material for absorbing water as the supercritical fluid with analyte flows therethrough, said water removing means in fluidic communication with the extraction vessel.

30. A system as described in claim 17 wherein the extraction chamber assembly has pressure retaining means able to withstand pressure up to 680 atm, and an extraction vessel within the extraction chamber assembly is contained by the pressure retaining means, said extraction vessel made of a material not able to independently withstand pressure greater than 50 atm, said vessel when disposed within the pressure retaining means and transmitting pressure therein to the pressure retaining means.

31. A system as described in claim 30 wherein the pressure retaining means is comprised of a first half and a second half which are hingeably connected to form a closed pressure chamber which holds the vessel when they are in contact, and release the vessel when they are not in contact.

32. A system as described in claim 17 wherein the extraction chamber assembly has pressure retaining means able to withstand pressure up to 680 atm, and an extraction vessel within the extraction chamber assembly is contained by the pressure retaining means, said extraction vessel made of a material not able to independently withstand pressure greater than 50 atm.

33. A system as described in claim 32 wherein the extraction vessel is porous.

34. A system as described in claim 33 wherein the vessel is made of teflon, PEEK, stainless steel, plastic or paper.

35. A system as described in claim 15 including high power heating means for heating the supercritical fluid to appropriate extraction temperature conditions before the supercritical fluid enters the extraction vessel, said high power heating means in thermal communication with an inlet to the extraction vessel.

36. A system as described in claim 35 wherein the extraction chamber assembly has thermal insulation to retain heat in the supercritical fluid when it enters the extraction chamber assembly to solubilize analyte in the matrix therein.

37. A system as described in claim 9 wherein the automated variable restrictor defines a channel therethrough, a portion of said channel having a variable inner diameter, and wherein the supercritical fluid includes modifier concentrations as great as 50%, said variable inner diameter of said channel adaptable to allow the fluid through the channel without clogging.

38. A system as described in claim 37 wherein the computer monitors flow of fluid through the channel and varies the diameter of the portion of the channel based on the flow of fluid through the channel.

39. A system as described in claim 38 wherein the automated variable restrictor has a maximum dead volume of 0.86 microliters.

40. An extraction vessel for use with supercritical fluid extraction comprising:

a container having a chamber, a first end having a first opening in fluidic communication with the chamber and a second end having a second opening in fluid communication with the chamber;

a first check valve disposed on the first end of the container for selectively sealing the first opening from the chamber; and

a second check valve disposed on the second end of the container for selectively sealing the second opening from the chamber, said container with the first check valve disposed on the first end and the second check valve disposed on the second end constructed and designed to contain fluid at supercritical temperatures and pressures.

41. An extraction vessel as described in claim 40 wherein each of the check valves is comprised of a seal portion and a spring portion in contact with the seal portion for biasing the seal portion against the respective opening.

42. An extraction vessel as described in claim 41 wherein each end of the container comprises a seal member defining the first and second openings, respectively, and each of the seal portions are spring biased against the respective seal member.

43. An extraction vessel for use with supercritical fluid extraction comprising:

a container having a chamber, a first end having a first opening in fluid communication with the chamber and a second end having a second opening;

a first breakable membrane sealing the first opening; and

a second breakable membrane sealing the second opening, said container with the first membrane sealing the first opening and with the second membrane sealing the second opening constructed and designed to contain fluid at supercritical temperatures and pressures.

44. An extraction vessel as described in claim 43 wherein the first and second membranes have a plurality of channels such that the first and second membranes fracture along the channels during puncturing of the first and second membranes.

45. An extraction vessel as described in claim 44 wherein the first and second membranes are comprised of teflon or PEEK material.

46. A system for supercritical fluid extraction comprising:

means for providing supercritical fluid for extracting analyte from a sample;

an extraction vessel having a sample therein, said extraction vessel in fluidic communication with the providing means such that supercritical fluid is provided to the extraction vessel to transfer analyte therefrom;

a vent valve for venting fluid from the extraction vessel to atmosphere, said vent valve located downstream of said extraction vessel and in fluidic communication with said extraction vessel, said vent valve having a first path and a second path; and

means for collecting analyte from the fluid, said collecting means in fluidic communication with the extraction vessel through the first path, said fluid vented from the extraction vessel away from the collection means along the second path.

47. A system as described in claim 46 including a computer for automatically controlling the vent valve.

48. A method for supercritical fluid extraction comprising the steps of:

extracting analyte from an extraction vessel with supercritical fluid;

collecting analyte from the supercritical fluid in a collection trap in fluidic communication with the extraction vessel; and

venting to atmosphere the supercritical fluid from the extraction vessel from a location downstream of the extraction vessel but upstream of the collection trap.

49. A method as described in claim 48 wherein the venting step includes the step of automatically controlling a vent valve with a computer.

50. A supercritical fluid extraction system comprising:

means for providing supercritical fluid for extracting analyte from a sample;

an extraction vessel having a sample therein, said extraction vessel in fluidic communication with the providing means such that supercritical fluid is provided to the extraction vessel to transfer analyte therefrom;

means for collecting analyte from the fluid, said collecting means in fluidic communication with the extraction vessel; and

means for controlling flow of the fluid from the providing means to the extraction vessel and to the collecting means such that any leaks and plugs can be detected.

51. A system as described in claim 50 wherein the controlling means comprises a plurality of valves for controlling the flow of fluid therethrough, said controlling means selectively controlling the valves and monitoring flow of the fluid through the valves in order to detect and identify leaks and plugs.

52. A system as described in claim 51 wherein the controlling means includes a computer which controls which valve is open or closed at a given time and monitors fluid flow.

53. An extraction system for supercritical fluid extraction comprising:

an extraction chamber assembly for extracting analyte from a sample with supercritical fluid; and

means for removing water from the supercritical fluid with analyte, said water removing means in fluidic communication the extraction chamber assembly.

54. An extraction vessel as described in claim 53 wherein the extracting means includes an extraction vessel having the sample within and the water removing means includes an absorbent vessel in fluidic communication with the extraction vessel having a material for absorbing water as the supercritical fluid with analyte flows therethrough, said water removing means in fluidic communication with the extraction vessel.

55. An extraction system as described in claim 54 wherein the material comprises sodium sulfate or magnesium sulfate.

56. An extraction system as described in claim 55 wherein the material is comprised of hydromatrix, a form of diatomaceous earth.

57. An extraction device for use with supercritical fluid extraction comprising:

an insert constructed and arranged for holding a sample, said insert being porous; and

a container having a chamber which contains the insert, said container operable to retain the pressure of the supercritical fluid within the insert.

58. An extraction device as described in claim 57 including means for providing supercritical fluid to the insert such that analyte can be extracted from the sample within the insert, said providing means in fluidic communication the insert.

59. An extraction system as described in claim 58 wherein the insert is made of teflon, PEEK, stainless steel, plastic or paper.

60. A system for use with supercritical fluid extraction comprising:

means for extracting analyte from a sample with supercritical fluid;

means for collecting analyte from the fluid;

said collecting means in fluidic communication with the extracting means;

means for providing desorbing solvent to the collecting means, said desorbent providing means in fluidic communication with the collecting means; and

a restrictor for controlling flow of fluid with analyte from the extracting means to the collecting means, said restrictor having a first port in fluidic communication with the extracting means, a second port in fluidic communication with the collecting means and a third port in fluid communication with desorbing providing means, said restrictor having a needle member and means for selectively moving the needle member such that the fluid with analyte is converted from a first supercritical pressure in the first port to a second pressure in the second port which is less than the first pressure; and

a computer for automatically controlling the moving means, said computer in communication with the moving means.

61. A restrictor as described in claim 60 including a body member having the first, second and third ports, said body member having a maximum dimension less than 1 inch and a dead volume of less than 1 microliter.

62. A restrictor as described in claim 61 wherein the needle member has a diameter of less than 1/16 of an inch.

63. A restrictor as described in claim 62 including a seat member disposed in the first, said seat member having a length less than 0.3 inches, said seat member having an internal diameter less than 0.016 inches, said seat member made of poly-ether-ether-ketone.

64. A restrictor as described in claim 63 having a total assembled length of less than 2.5 inches and having a total assembled width of less than 1.5 inches.

65. A restrictor as described in claim 60 wherein the selectively moving means moves the needle member based on flow rate of fluid between the first port and the second port.

66. A restrictor as described in claim 65 wherein the supercritical fluid includes modifier concentrations as great as 50% and the moving means moves the needle member to allow the fluid to pass between the first and second ports without clogging.

67. A pumping system for providing supercritical fluid comprising:

an output from which supercritical fluid at a desired pressure and flowrate passes;

means for providing supercritical fluid to the output, said providing means in fluidic communication with the output, said providing means having at least one variable speed piston which pressurizes the fluid, the speed of the piston at a given time corresponding to the pressure and flowrate of the fluid which passes from the output at the given time; and

microprocessor control means for controlling the providing means such that the pressure and flowrate of the supercritical fluid provided by the output is maintained at a desired pressure and flowrate.

68. A pumping system as described in claim 67 wherein the providing means includes a source tank, a pump assembly having the piston in fluid communication with the source tank and a motor for driving the piston, said motor having a variable power input which is controlled by said microprocessor control means.

69. A pumping system as described in claim 68 wherein microprocessor control means includes a pressure transducer for measuring the pressure of the supercritical fluid at the output, said pressure transducer in fluidic communication with the output.

70. A pumping system as described in claim 69 wherein the microprocessor control means comprises a piston position potentiometer.

71. A pumping system as described in claim 70 wherein the output comprises a damping chamber which maintains the fluid passing therefrom essentially at a constant pressure.

72. A pumping system as described in claim 71 wherein the pump assembly comprises means for providing rotary motion, and means for converting the rotary motion into linear motion to drive the piston.

73. A pumping system as described in claim 72 wherein the rotary motion providing means comprises a pully and belt system connected to the motor and a crankshaft connected to the pulley system.

74. A pumping system as described in claim 73 wherein the means for converting the rotary motion into linear motion comprises a crank arm which is connected to the crankshaft at a first end and the piston at a second end.

75. An extraction system for supercritical fluid extraction comprising:

an extraction vessel having a sample therein; and

means for providing supercritical fluid to the extraction vessel so that supercritical fluid can flow through the extraction vessel and extract analyte from the sample, said providing means including means for heating the supercritical fluid to a desired extraction temperature before the supercritical fluid enters the extraction vessel, said supercritical fluid heating means is disposed within a plunger or inlet to the extraction vessel which moves the extraction vessel into fluidic communication with the extraction system for supercritical fluid extraction.

76. A method for supercritical fluid extraction comprising the steps of:

moving an extraction vessel having a sample from a carousel having a plurality of extraction vessels each having a sample with an automated moving device into fluidic communication with a supercritical fluid extraction system so that the supercritical fluid can flow through the extraction vessel and extract analyte from the sample;

extracting analyte from the sample with supercritical fluid and providing a microprocessor means for individuallly programming each vessel with extraction process parameters.

77. A method as described in claim 76 wherein after the step of extracting analyte, there is the step of collecting analyte from the fluid.

78. A method as described in claim 77 wherein after the collecting step, there is the step of analyzing the analyte with a liquid or gas chromatograph.

79. A method as described in claim 78 wherein the extracting analyte step includes the step of extracting analyte from a sample with supercritical fluid under automated control by the supercritical fluid extraction device.

80. A supercritical fluid extraction system comprising:

means for providing supercritical fluid for extracting analyte from a sample;

means for holding a plurality of extraction vessels each having a sample therein;

means for selectively moving an extraction vessel from the holding device into fluid communication with the supercritical fluid providing means so that supercritical fluid can flow through said extraction vessel and gather analyte from the sample.

81. A supercritical fluid extraction device as described in claim 80 including means for collecting analyte from the fluid with analyte, said collecting means in fluidic communication with the extraction vessel.

82. A system for supercritical fluid extraction comprising:

an extraction chamber assembly in which a sample matrix with analyte has the analyte solubilized with supercritical fluid;

means for collecting the analyte, said collecting means connected to the extraction chamber assembly through plumbing;

means for providing supercritical fluid to the extraction chamber and connected thereto with plumbing;

means for providing modifier to the extraction chamber assembly and connected thereto with plumbing; and

means for flushing the plumbing, extraction chamber assembly and collecting means with a desired fluid to cleanse it.

83. A system as described in claim 82 wherein the flushing means includes a blank vessel which, when disposed in the extraction chamber assembly, allows desired fluid to flow therethrough and cleanse the plumbing and collecting means;

and including a computer connected to the modifier providing means and the supercritical fluid providing means for controlling the same such that the desired fluid flushing is obtained.

84. An apparatus for collecting analyte from supercritical fluid extraction comprising:

a collection trap in which analyte is collected;

means for providing desorbing fluid to the collection trap which dissolves the analyte therein, said desorbing providing means connected to the collection trap;

a fraction collection carousel having a first vial and at least a second vial, said fraction collection carousel in fluidic communication with the collection trap so desorbing fluid with dissolved analyte is received by a desired vial; and

a computer in communication with the fraction collection carousel to position so a desired vial is in place to receive the desorbing fluid with dissolved analyte, and in communication with the desorbing fluid providing means to cause the desorbing fluid providing means to provide a desired desorbing fluid at a desired time.

85. An apparatus as described in claim 84 including a cooling unit which maintains the fraction collection carousel at a. desired temperature, said cooling unit disposed adjacent to and in thermal communication with the fraction collection carousel.

86. An extraction chamber assembly comprising:

pressure retaining means comprised of a first half and a second half which are hingeably connected to form a closed pressure chamber in which pressure up to 680 atm can be supported, said chamber receiving an extraction vessel holding a sample matrix, said chamber holds the vessel when they are in contact, and releases the vessel when they are not in contact; and

means for heating the chamber, said heating means in thermal communication with the chamber and adjacent the pressure retaining means.

87. A system for supercritical fluid extraction comprising:

an extraction chamber assembly in which a sample matrix with analyte has the analyte solubilized with supercritical fluid;

means for collecting the analyte, said collecting means connected to the extraction chamber assembly through plumbing;

means for providing supercritical fluid to the extraction chamber and connected thereto with plumbing; and

means for automatically controlling operation of the extraction chamber assembly, the collecting means and the providing means such that the analyte is extracted and collected at a desired pressure and a desired temperature with the desired supercritical fluid at a desired flow rate at a desired time, said controlling means in communication with the extraction chamber assembly, the collecting means and the providing means.

88. A supercritical fluid extraction system comprising:

a carousel for holding a plurality of extraction vessels, each extraction vessel having a sample;

an extraction chamber disposed adjacent to the carousel;

a mechanism for moving an extraction vessel from the carousel to the extraction chamber, said moving mechanism in communication with the carousel and the extraction chamber;

a pump for pumping supercritical fluid to the extraction vessel in the extraction chamber to extract analyte from the sample;

a variable restrictor for reducing the pressure of the supercritical fluid, said variable restrictor connected to the extraction chamber and microprocessor means for individually programming each vessel with extraction process parameters.

89. A method for extracting analyte comprising the steps of:

moving an extraction vessel having a sample from a plurality of extraction vessels each having samples with a moving mechanism;

placing the extraction vessel into an extraction chamber;

introducing supercritical fluid to the extraction vessel to extract analyte from the sample;

flowing the supercritical fluid from the extraction chamber through a variable restrictor to reduce the pressure of the supercritical fluid and providing a microprocessor means for individually programming each vessel with extraction process parameters.

90. A method as described in claim 89 wherein the flowing step includes the steps of:

flowing the supercritical fluid through a channel to reduce the pressure of the supercritical fluid; and

varying the diameter of the channel to maintain a desired flow of the supercritical fluid through the channel.

91. An extraction apparatus comprising:

a mechanism for automatically performing supercritical fluid extraction on a series of samples one after the other without substantially handling the apparatus for supercritical fluid extraction between extractions;

said mechanism for automatically performing supercritical fluid extractions including;

an extraction chamber assembly having an interior, an exterior, an orifice for introduction of sample, a first port for fluid entrance and at least a second port for a fluid outlet;

a sample injector mechanism for automatically injecting into the extraction chamber assembly a series of samples from a storage apparatus for feeding samples in series and for extracting each sample prior to introducing the next sample; and

a variable restrictor for reducing pressure of supercritical fluid after extraction has occurred in the extraction chamber assembly and microprocessor means for individually programming each vessel with extraction process parameters.

92. A method for supercritical fluid extraction of a sample comprising the steps of:

extracting under supercritical conditions by;

automatically injecting a series of samples into an extraction chamber assembly having an interior, an exterior, an orifice for introducing of sample, a first port for fluid entrance and at least a second port for a fluid outlet;

extracting each sample prior to introducing a next sample with solvent at a supercritical pressure;

flowing the fluid at the supercritical pressure through a variable restrictor to reduce the pressure and providing a microprocessor means for individually programming each vessel with extraction process parameters.