Hewlett-packard Company

Christopher M Wurm

Lenore R Frank

Paul C Dryden

Steven J Engel

Mark A Nickerson

Ernest H Zerenner

Lee H Altmayer

Methods and apparatus for extracting sample components from complex matrices using supercritical fluid as the principal extracting solvent are disclosed. The invention takes advantage of the fact that the solvent power of a supercritical fluid is stepwise settable by the parameters of density, modifier concentration, and temperature. Accordingly, methods and apparatus for extracting a component from a sample using fluid flow system having a variable and controllable flow restriction are disclosed. The methods of the present invention comprise the steps of inserting the sample into the sample container section, inputting temperature, pressure, flow rate and extraction time set points. Flow rate is controlled and system pressure regulated by the variable flow restriction. The output stream from the extraction is then expanded through a nozzle and into a trap. In certain embodiments, the trap is filled with chemically active packing material. In other embodiments, a fractionation zone and other analytical instruments are coupled to the apparatus of the present invention. Methods and apparatus for rinsing the extraction instrument and for diluting the extraction fluid are also disclosed. Methods for operating a supercritical fluid extraction systems comprising a pressure and thermal control systems which are programmable to regulate the system to maintain such values within the design specifications during the extraction process.

Decoupled flow and pressure setpoints in an extraction instrument using

Method and apparatus for regulating the passage of fluid through a chamber or other type of conduit. Fluid passage is terminated when the volume of fluid which has swept through a chamber equals a selected multiple of the chamber's internal volume, which multiple is known as swept chamber volumes.

Method and apparatus for regulating fluid flow

Methods and apparatus for extracting sample components from complex matrices using supercritical fluid as the principal extracting solvent are disclosed. The invention takes advantage of the fact that the solvent power of a supercritical fluid is stepwise settable by the parameters of density, modifier concentration, and temperature. Accordingly, methods and apparatus for extracting a component from a sample using fluid flow system having a variable and controllable flow restriction are disclosed. The methods of the present invention comprise the steps of inserting the sample into the sample container section, inputting temperature, pressure, flow rate and extraction time set points. Flow rate is controlled and system pressure regulated by the variable flow restriction. The output stream from the extraction is then expanded through a nozzle and into a trap. In certain embodiments, the trap is filled with chemically active packing material. In other embodiments, a fractionation zone and other analytical instruments are coupled to the apparatus of the present invention. Methods and apparatus for rinsing the extraction instrument and for diluting the extraction fluid are also disclosed. Methods for operating a supercritical fluid extraction systems comprising a pressure and thermal control systems which are programmable to regulate the system to maintain such values within the design specifications during the extraction process are also disclosed.

A method of creating a self-documenting logfile which records the status and operation of a substantially computer-controlled device. The method comprises the steps of accepting input commands from a user for controlling the device status and operation; monitoring the device characteristics; detecting deviations in the device status, user inputs, and procedural steps in the device's operation; writing these detected events to the logfile with the date and time of which the detected event occurred; and retrieving the logfile upon user demands for review of the logfile. In order to comply with good laboratory practices (GLP), the method additionally comprises steps for verifying the user input commands by determining the acceptability of the input commands, detecting inadvertent alteration to the logfile and testing the validity of the logfile for invalid data. Steps for providing an enciphering key within the event lines which comprise the logfile in order to detect tampering are also disclosed.

Self documenting record of instrument activity and error messages

Methods and apparatus for extracting sample components from complex matrices using supercritical carbon dioxide as the principal extracting solvent are disclosed. The present invention takes advantage of the fact that the solvent power of a supercritical fluid is stepwise settable by the parameters of density, modifier concentration, and temperature. Accordingly, methods and apparatus for extracting a component from a sample using flow system having a variable and controllable flow restriction are disclosed. The methods of the present invention comprise the steps of inserting the sample into the sample container section, inputting temperature, pressure, flow rate and extraction time setpoints. The flow rate is controlled and the system pressure regulated by the variable flow restriction. The present invention contemplates opening and closing the orifice in order to control the variable flow restriction, or closing the orifice until setpoint pressure is achieved and controlling the restriction of the orifice to maintain the setpoint pressure.The present invention also discloses apparatus for the extraction of components from a sample which include means for regulating the pressure and flowrate of a supercritical extraction solvent.

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Landenberg, PA, United States of America

Christopher M Wurm