Abstract: Gas chromatographs are disclosed that may be constructed to be portable, light, rugged, fast, sensitive, and to use only utilities (compressed gas and electricity) that are readily available in the field. The gas chromatographs can also perform novel extractions of analytes from gaseous, liquid, or solid samples. The chromatographs can be truly portable; they can operate with approximately 100 watts of power (at peak power consumption); and they are extremely fast. The chromatographs are not limited just to portable applications, but will also find many uses within laboratories, because they require minimal laboratory bench or other space, because they can operate at high speed, and because they can operate with minimal consumption of utilities (compressed gases, air conditioning, etc.).

Abstract: A process is described for the separation of a mixture of substances by sorption of the mixture's components on two different sorption agents, which are individually and independently adjustable in their sorption properties, and is performed in a manner by which the mixture of substances to be separated is introduced into a separation chamber between the surfaces of the sorption agents, and in which the separation chamber is occupied by a gap medium, in which the mixture's components can be dissolved and/or dispersed and/or evaporated, while the phases containing the sorption agents move in opposing directions, and the separated components of the mixture held on the sorption agents are recovered after passage through the separation path. This process is characterized in that the separation chamber is formed by at least two or several hollow, concentrically superimposed cylindrical disks Z.sub.A and Z.sub.B, which are filled with structural elements, and which contain separation media Ph.sub.A and Ph.sub.

Abstract: A gas chromatograph system including a cold trap having two portions, a capillary tube and a porous layer open tubular (PLOT) column, for substantially simultaneously trapping lower and higher boiling point gasses. The capillary tube enables cold trapping of lower boiling point gasses while the PLOT column enables cold trapping of higher boiling point gasses. The capillary tube interconnects at one end to an analytical column and a sample gas source and interconnects at its other end to a first end of the PLOT column. The other end of the PLOT column interconnects to a carrier gas source and a vacuum source. The capillary tube and PLOT column are both positioned within a temperature controlled environment of the cold trap. During the collection mode, the temperature control device maintains a relatively low temperature to condense the sample components.

Abstract: A multidimensional gas chromatograph (GC) system having wide bore capillary and narrow bore capillary GC columns in series and having a novel system interface. Heart cuts from a high flow rate sample, separated by a wide bore GC column, are collected and directed to a narrow bore GC column with carrier gas injected at a lower flow compatible with a mass spectrometer. A bimodal six-way valve is connected with the wide bore GC column outlet and a bimodal four-way valve is connected with the narrow bore GC column inlet. A trapping and retaining circuit with a cold trap is connected with the six-way valve and a transfer circuit interconnects the two valves.

Abstract: An on-line multidimensional system which includes a liquid chromatograph having an on-line connection to a pyrolysis probe, which in turn has on-line connection to a gas chromatograph. Preferred applications use a size-exclusion chromatograph coupled to a pyrolysis probe coupled to a gas chromatograph to simultaneously produce composition as a function of molecular weight/size information for polymeric materials.

Abstract: 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.

Abstract: A method and device are disclosed for performing supercritical fluid chromatography in packed columns of at least about 0.5 mm inside diameter. The column provides at least 50,000, preferably at least 100,000, theoretical plates with pressure drop across the column of at least 25 bar. The outlet pressure is controlled by the back pressure regulator. The column may comprise a plurality of individual columns in series. Separation is performed at a rate of at least 25 plates/min, preferably at least 100 plates/min.

Abstract: A gas chromatography system featuring column bifurcation and pressure tuning. The system of this invention incorporates a bifurcated system in which samples eluting from a first separation column are directed selectively through one of two or more additional separation columns. Flow directing is achieved through the use of valves which switch carrier gas which are outside of the path of the analyte mixture. Effective tuning of the system is provided by adjusting the intermediate pressure which controls the effective lengths of the initial separation column and the additional final separation columns.