Hewlett-packard Company

Steven J Engel

Paul C Dryden

Lenore R Frank

Mark A Nickerson

Ernest H Zerenner

Christopher M Wurm

Kurt B Augenblick

Kimber D Fogelman

Robert P Rhodes

David E Clouser

Paul B Crilly

Lesley M Freed

Christoper M Wurm

Richard E Marsh

Charles T Coffey

Methods and apparatus for collecting gasses from the sample headspace of a sealed sample container are disclosed. The gasses in the sample headspace are withdrawn by inserting a probe into the sample headspace and permitting the gasses to flow into an external headspace. The probe is then disconnected from the sample to seal the external headspace and the external headspace is then connected to an analytical instrument such as a gas chromatograph to permit the sample gasses to be transferred out of the external headspace and into the instrument. The step of transferring the gasses is preferably accomplished by connecting a source of carrier gas to an inlet port of the external headspace and sweeping the sample gasses from the external headspace. In certain preferred embodiments of the present invention, vibration is used to promote the formation of sample gasses either by vibrating the sample container itself or by moving the sample container relative to a stop to vibrate a septum which seals the sample container in certain embodiments. In these embodiments, the agitation created by such vibrations increases the rate of outgassing from the sample to the sample headspace. Also, in certain embodiments, the external headspace includes a flexible portion that is vibrated to agitate the external headspace and thereby promote uniform dispersion of sample gasses throughout the headspace.

Headspace sampling system

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

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.

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.

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.

The bar code on the cylindrical surface of an object is accurately read by rotating the object past a bar code reader so that the bar code passes the reader a plurality of times. Each of the readings from the reader is compared with the other readings and a final reading is provided when several of the same readings is obtained in succession. The object may be rotated pass the reader first in one direction and then in the opposite direction to assure a proper reading in the event that the bar code is backwards. Also, the object may be rotated at a varying speed to obtain the optimum scan speed for the particular density of the bar code.

Method and apparatus for reading a bar code

An analog-to-digital converter system is disclosed in which the amplitude of the signal is compressed by means including a logging means prior to an analog-to-digital converter. Reference signals of known values are applied to the logging means and their values at the output of the converter are used to determine a linearity factor which is applied to a multiplier coupled to the output of the converter. The amplitude of one of the reference signals at the output of the multiplier is compared with what it should be and the difference is added by an adder at the output of the multiplier.

Autocalibration of compressed A/D converter

The linear component appearing in the output of two logarithmic amplifiers connected for temperature compensation and having matched feedback semiconductor devices is cancelled in a resistor connected in series with a logarithmic device between the output and a point of reference potential so that a purely logarithmic voltage appears at their junction.

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Kennett Square, PA, United States of America

Steven J Engel