摘要:
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 invention contemplates opening and closing an orifice in order to control the variable flow restriction, or closing the orifice until set point pressure is achieved and controlling the restriction of the orifice to maintain the set point pressure. The present invention also discloses apparatus for the extraction of components from a sample which include means for regulating the pressure and flow rate of a supercritical extraction solvent.
摘要:
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.
摘要:
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.
摘要:
A method and apparatus for sample screening and sample preparation within a vessel sealed with a cap, the vessel having at least a portion of the inside surface coated with a stationary phase having an affinity for analytes of interest. A sample possibly containing such analytes is introduced into the vessel whereby the analytes of interest migrate out of the sample and into the stationary phase for detection by a screening device and for desorption.
摘要:
A solenoid driven valve is disclosed which is adaptable for controlling the introduction of a high pressure fluid into a fluid trapping assembly having an absorption column topped with an annular orifice expansion nozzle. The valve has an inlet port to introduce high pressure fluid, an axially moving solenoid driven pin which engages means to restrict fluid flow into said column. A diaphragm is located within the valve to direct fluid into the column and which separates the fluid in a region of high pressure from ambient pressures.
摘要:
Methods and apparatus for extracting an analyte from a sample using a field-portable extraction instrument. The preferred embodiment of the extraction instrument includes an extraction fluid source, a sample container, a valve element, a nozzle, and a collection trap vessel. The methods of the present invention include the steps of inserting the sample into the sample container, attaching the sample container to the instrument, and providing a quantity of pressurized extraction fluid from the pressurized extraction fluid source into the sample container to initiate the extraction process. Extraction is facilitated by directing the extraction fluid into the sample at a rapid flow rate such that the sample and extraction fluid are vigorously mixed and a sample/solvent mixture is created. The valve element is then operated to isolate the extraction fluid source and to fully close the sample container. As an optional step, heat may be applied to the closed sample container to create conditions for effecting supercritical fluid extraction. The valve element is then operated to direct a fluid/constituent mixture from the sample container section to the collection trap vessel. The analyte of interest that is present in the fluid/constituent mixture is thereby trapped.
摘要:
A method and apparatus for accurately regulating the compressibility of a compressible fluid in a pumping system utilizing a single zone of controlled cooling. Cryogenic cooling is employed for cooling a pump head and a thermally integrated heat exchanger such that a single source of cryogenic fluid can be applied to the heat exchanger to increase the bulk modulus of the compressible fluid just prior to and during the pumping process.
摘要:
A preferred sample introduction apparatus includes a wall that defines a channel, with the channel being configured to receive a sample and being adapted to engage in fluid communication with the separation column of a chromatographic apparatus. Preferably, a coating of semi-conductive material is arranged adjacent to at least a portion of the wall. Additionally, a heater controller is provided which electro-magnetically communicates with the coating. So configured, the coating, in response to receiving energy from the heater controller, increases in temperature, thereby increasing a temperature of the sample.
摘要:
A solenoid driven valve is disclosed which is adaptable for controlling the introduction of a high pressure fluid into a fluid trapping assembly having an absorption column topped with an annular orifice expansion nozzle. The valve has an inlet port to introduce high pressure fluid, an axially moving solenoid driven pin which engages means to restrict fluid flow into said column. A diaphragm is located within the valve to direct fluid into the column and which separates the fluid in a region of high pressure from ambient pressures.
摘要:
A solenoid driven valve is disclosed which is adaptable for controlling the introduction of a high pressure fluid into a fluid trapping assembly having an absorption column topped with an annular orifice expansion nozzle. The valve has an inlet port to introduce high pressure fluid, an axially moving solenoid driven pin which engages means to restrict fluid flow into said column. A diaphragm is located within the valve to direct fluid into the column and which separates the fluid in a region of high pressure from ambient pressures.