Abstract: A single stage flow modulator for performing comprehensive chromatography comprises a first chromatographic column, a valve fluidically coupled to at least two fluid conduits, wherein when in a first position, the valve directs a control flow to direct an output of the first chromatographic column to a first detector, and wherein when in a second position, the valve directs a control flow to direct a portion of an output of the first chromatographic column to a second chromatographic column, wherein the portion of the output of the first chromatographic column directed to the second chromatographic column is continuously modulated throughout a sample run.

Abstract: A seal forming a fluid tight connection between a gas chromatography column and a sample inlet assembly is disclosed. The seal is formed by a metal injection molding process. The seal has a first surface adapted for sealing with the sample inlet assembly and a second surface adapted for sealing with the column. The seal has an aperture extending between the first and second surfaces. A method of sealing a connection between a gas chromatography sample inlet assembly and a gas chromatography column is also disclosed. The method includes providing a seal as described above, compressing the first surface of the seal against an end of the inlet assembly, positioning the column in fluid communication with the aperture, and engaging the column with the second surface.

Abstract: A self-contained chromatography system is provided and includes a chromatography column, a carrier gas reservoir containing a carrier gas and an analyte stream processing device, wherein the carrier gas reservoir is disposed upstream from the chromatography column and wherein the analyte stream processing device is disposed downstream from the chromatography column. A method for implementing the self-contained chromatography system is also provided and includes generating a first system pressure upstream from the chromatography column and a second system pressure downstream from the chromatography column to cause the carrier gas to flow between the carrier gas reservoir and the analyte stream processing device. The method further includes combining a sample material with the carrier gas, introducing the combined sample to the chromatography column to generate the analyte stream and processing the analyte stream via the analyte stream processing device.

Abstract: A method is described for recovering a noble gas, such as xenon or krypton, from a first gas mixture comprising a plurality of components, one of which is the noble gas and the others are typically helium and/or nitrogen, argon, and relatively light fluorocarbons. The gas mixture is first conveyed to a gas chromatography column for separating the noble gas from the other components of the gas mixture. As the noble gas travels relatively slowly through the column, the other components are exhausted from the column before the relatively slow noble gas. Following the exhaust of these other components, a purge gas is supplied to the column to flush the noble gas therefrom. A second gas mixture comprising the noble gas and the purge gas is conveyed from the column to a membrane separator to separate the second gas mixture into a noble gas-rich gas stream and a purge gas-rich gas stream, which may be recirculated back to the column for re-use.

Abstract: Methods and systems for cooling gas chromatography ovens that comprise a housing having a fluid entry and a sleeve positioned within the housing to provide a fluid gap between the inner surface of the housing and the outer surface of the sleeve, where the sleeve is coupled to the fluid entry, and where a cooling fluid from the fluid entry traverses the inner layer of the sleeve and thereafter the outer layer of the sleeve via the fluid gap. In one embodiment, the housing includes at least one adjustable fluid exit, and the fluid gap is in fluid communications with the fluid exit(s). The fluid entry and the sleeve can be concentric, and the sleeve can include a heating element. A fan can be positioned to drive the cooling fluid from the fluid entry.

Abstract: An inlet seal assembly for sealing an injection port member in a chromatography instrument , comprising an injection port member having a raised metal ring, an inlet seal member with an upper surface, a peripheral groove formed in the inlet seal member upper surface, a soft resinous plastic material ring positioned in the peripheral groove opposite the raised metal sealing ring, a reducing nut holding the inlet seal member against the injection port member, and threads connecting the reducing nut to the injection port member whereby to press the soft ring against the raised metal sealing ring to form a seal. The inlet seal assembly also may have a bottom seal between the inlet seal member and the reducing nut. A method of making and using the inlet seal assembly.

Abstract: An interface placed between a gas chromatograph part and a mass spectrometer part of a gas chromatograph mass spectrometer for allowing one or two columns to pass air-tightly from the gas chromatograph part to the mass spectrometer part. The interface includes: a heat-retention block having a small-diameter hole allowing two columns to pass through; a single-hole ferrule having a small-diameter hole allowing a single column to pass through; and a two-hole ferrule having two small-diameter holes allowing two columns to respectively pass through. An adapter is placed between the heat-retention block and the two-column nut. It includes a long large-diameter opening allowing two columns passing through the two-hole ferrule to converge on the small-diameter hole of the heat-retention block. The interface also includes a single-column nut for pressing the single-hole ferrule to the heat-retention block; and a two-column nut for pressing the two-hole ferrule to the adapter.

Abstract: Disclosed are systems and methods that include a thermal desorption unit, a chromatographic column, and an interface device between the unit and the column. The interface device controls the fluid flowing into the column, such as by providing additional carrier gas to maintain a substantially constant gas flow or velocity, by proving a controlled temperature increase, or by venting a portion of the gas received from the thermal desorption unit, thereby removing the dependence on the thermal desorption unit for such control. In some embodiments, the interface is a chromatographic injector. In certain embodiments, a transfer line from the desorption unit is coupled to the same port of the interface device as the chromatographic column. In some of these embodiments, this is accomplished by employing a special adaptor.

Abstract: An inlet includes a bottom assembly and a top assembly. The bottom assembly includes at least one male unit, and the top assembly has at least one beveled surface and includes at least one female unit and a lateral driving unit. The top assembly is placed inside the bottom assembly by aligning the female unit of the top assembly with the male unit of the bottom assembly. The lateral driving unit laterally drives the top assembly and causes the beveled surface of the top assembly to rise against the male unit of the bottom assembly, allowing the top assembly to seal with the bottom assembly.

Abstract: A gas chromatography/mass spectrometry system includes two sample introduction parts, a gas chromatography part having two columns, a column oven for housing the two columns in a parallel configuration, an interface part through which an outlet end of each of the two columns is inserted, and a mass spectrometry part. The mass spectrometry part has an ionization chamber to which the outlet ends of the columns inserted through the interface part are connected, a mass separation part, an ion detector, and a vacuum chamber for housing the ionization chamber, the mass separation part, and the detector. Because the outlet ends of the parallel columns are both connected to the ionization chamber, the carrier gas flow and line velocity are the same as though there is one column, thereby avoiding line stagnation. Since analyses can be performed selectively with a single system, results having high reliability and precision can be obtained.

Abstract: A thermal conductivity detector includes separate sample gas and reference gas chambers. Each chamber has a gas inlet and a gas outlet and a sensor. The chambers are connected by at least one passageway. For example, a passageway can extend from the sample gas chamber to the reference gas chamber adjacent the gas inlets. As a further example, a passageway can be provided adjacent the gas outlets. More specifically, an exhaust passageway extends from the first passageway to the additional passageway and there is an exhaust outlet connected to the additional passageway.

Abstract: A coupling device connecting the output of a microchromatograph (?CG) to the input of a mass spectrometer (MS), said coupling device comprising a capillary tube with one end connected in sealed fashion to the source under vacuum of the mass spectrometer through the intermediary of an interface device, and with the other end connected to the output of the microchromatograph, in slack fashion, open to the atmosphere; the length and the diameter of the capillary tube being chosen such that the flow rate inside the capillary tube is very close to the flow rate at the output from the microchromatograph; the interface device being, furthermore, provided with heating means for very precise adjustment of the flow rate registered by the capillary.

Abstract: The invention relates to a chromatography column for high-pressure liquid chromatography, which can be provided with different connection systems, such as a cartridge retaining device or a reducing screw. The column tube (1, 11) of the inventive chromatography column has an external thread (4,18) at each end and at least one groove (3,14).

Abstract: This invention provides a reduced power consumption gas chromatograph system (10) which includes a capillary gas chromatograph column member (12) which contains a chemical sample to be analyzed. The gas chromatograph system further includes a heating mechanism (16) which extends throughout the length of the capillary gas chromatograph column member (12) and surrounds both the member (12) and a temperature sensing mechanism (14) which is mounted adjacent to the column member (12). The temperature sensing mechanism (14), the heating mechanism (16) and the column member (12) form a chromatograph column assembly (20) which includes a coiled section (28) where the components are tightly packed with respect to each other and allows for a reduced power consumption for temperature programming miniature gas chromatography column assemblies.

Abstract: A separation column for analyzing a gas includes a capillary which is filled with a separation material. In order to be able to use the separation column in a microsystem technology, spheres are used as the separation material. The spheres all have the same diameter. The diameters of the spheres are slightly smaller than the internal diameter of the capillary or are matched to the internal diameter of the capillary. The spheres are provided inside the capillary in a row one behind the other.

Abstract: A replaceable injection liner for a gas chromatograph is disclosed having a laterally extending external flange at its input end against which an injection septum is placed. A closure cap is positioned over and around the external flange and the injection septum to seal the septum against the flange, the septum closing and sealing the input end of the injection liner. The liner has a seal positioned beyond the flange to seal the interior surface of the injector and isolate it from the atmosphere and the injector's internal pressure.

Abstract: A gas chromatography split injector including a housing having a carrier gas inlet port and a vent port and an injector liner is provided. The injector liner includes a substantially cylindrical outer liner member disposed within the housing and an inner liner member disposed within the outer liner member. The inner liner member has substantially cylindrical upper and lower portions and a constriction therebetween. The constriction includes an inner surface having an inner diameter smaller than a diameter of inner surfaces of the upper and lower portions. The injector also includes a chromatographic column passing through the lower portion of the inner liner member and is in sealing engagement with the constriction of the inner liner member. A transfer line passing through the upper portion of the inner liner member and has an end located proximate to the constriction of the inner liner member.

Abstract: To switch gas flows between gas sources and gas sinks, a gas flow switching device includes gas passages, which communicate with one another and which have connecting points for the gas sources and the gas sinks. Furthermore, the gas flow switching device has a device for setting different pressures. To simplify the construction of the gas flow switching device and to achieve precisely defined pressure and flow conditions without the need for calibration, the gas flow switching device has two plates (9, 10), which are positioned on top of one another and joined together. The two plates (9, 10) have congruent channels (11) on their respective sides that face one another. These channels (11) have semicircular cross sections and form gas passages (4 to 8). In addition, at their lateral exit points from the plates (9, 10), the channels (11) form connecting points (12 to 17).

Abstract: A gas chromatograph or other analytical instrument requiring controlled fluid flow incorporates a manifold assembly that eliminates the need for many of the external fittings and connections required in the instrument. A manifold block has plural fluid flow paths formed therethrough to route fluids to selected components. A collar mates to the block and adapts to a rotary injection valve to provide the continued fluid paths from the block to the injector valve and the other components of the instrument.

Abstract: A cartridge holder includes a holder body having a cavity along a longitudinal axis of the holder body. A floating screw has a longitudinal axis and a hole through the length of the floating screw. The floating screw is adapted to engage with the cavity in such a way that the floating screw is movable relative to the holder body along the longitudinal axis of the holder body. But rotary movement of the floating screw around the longitudinal axis of the holder body is confined by a restriction of the cavity. An outlet unit having a stem with a central hole and a length greater than that of the floating screw is adapted to be movably inserted into the hole of the floating screw, so that a first end of the outlet unit extends out of the hole and a second end of the outlet unit is engaged with the cavity. An end cap is provided to engage with the cavity. In use a cartridge is placed inside the cavity of the holder body between the end cap and the outlet unit.

Abstract: An apparatus and method for sealing a plurality of columns containing media for use in liquid chromatography. The invention involves two sealing assemblies, each having a plurality of sealing heads. The sealing heads are sized to receive ends of the columns and to seal the columns when the heads are compressed. Compressive force is exerted by or through springs to permit the sealing heads to adapt to the length of the media bed within each column. The apparatus may include a pressure containment vessel for subjecting the columns to radial compression.

Abstract: A device for establishing a flange connection, having a bearing which can act on a first flange, a counter-bearing which can act on a second flange, and a connecting lever between the two bearings is described. The invention is distinguished by the fact that the connecting lever is a lever with a drawing element. The drawing element and the lever each have a first and second end. The drawing element's first end engages the bearing and its second end jointedly mounts in between the first and second ends of the lever. The counter-bearing has at least one contact location for the first end of the lever and a recess for the drawing element.

Abstract: A gas chromatographic system for analyzing gas components includes an analyzer, a constant temperature oven, an analyzer case, an indicator, an integrated sample conditioner, and a coupler. The analyzer includes a sample valve having a detector and a heater built therein and first and second columns wound around the periphery of the sample valve. The constant temperature oven accommodates the analyzer unit therein. The analyzer case accommodates the constant temperature oven. The indicator is protruded from the analyzer case to display analysis processes and results. The integrated sample conditioner provides an optimal condition for analysis. The coupler couples the analyzer unit with the sample conditioner so as to supply a sample gas and one of a carrier gas and a reference gas from the sample conditioner to the analyzer unit.

Abstract: A gas chromatograph includes a heating enclosure, an injection port extending through a wall of the enclosure, a capillary column within the heating enclosure and connected at a distal end thereof to a detector. The injection port is arranged to accept a carrier gas for gaseous components an analyte solution through the capillary column to the detector. An expansion chamber is located within the heating enclosure between the injection port and the capillary column. The expansion chamber is arranged such that it provides fluid communication between the injection port and the capillary column. First and second conduits are attached to the expansion chamber in fluid communication therewith. The first conduit is arranged to accept the carrier gas from outside the heating enclosure and the second conduit is arranged to vent excess vapor from the chamber to a point outside the heating enclosure.

Abstract: An apparatus for the recognition of exchangeable parts in an analytical measuring instrument or in an analytical measurement system with several analytical devices, which contain exchangeable parts has identification modules each attached to an exchangeable part, and transmit-receive devices which can receive information signals from an identification module and send information signals to an identification module, and a control device which evaluates the information from an identification module. The control device can cause a message to be displayed on a display device, if the information read out from an identification module does not fulfill certain conditions, for example with regard to the quality of the corresponding part.

Abstract: A vacuum degassing and solvent delivery apparatus for those solvents being utilized in high pressure liquid chromatographic operations and/or applications. The degassing and delivery apparatus of the present invention is designed for attachment directly to a solvent reservoir, such as a double-ended bottle having a threaded portion along the bottom end thereof. The arrangement facilitates ease of installation and removal of the vacuum degassing, recycling and delivery apparatus so as to accommodate a variety of installation applications and requirements. The solvent degassing system of the present invention further includes the utilization of an atmospheric impermeable composite tubing structure which is effective for isolating fluids from atmospheric contamination during transport.

Abstract: A device for performing sample acquisition and introduction of a selectable quantity of the acquired sample to associated device such as an analytical instrument.

Abstract: An analytical instrument includes a control system, including a computer and a pneumatic controller responsive to the computer, and a planar chromatographic assembly. The planar chromatographic assembly includes a planar pneumatic manifold, a heater/fan assembly for establishing a temperature-controlled zone, an insulating enclosure for confining the temperature-controlled zone to an oven cavity and certain zones of the planar pneumatic manifold, a separation column having inlet and outlet ends attached to couplers at selected internal fluid-bearing conduits in the pneumatic manifold and located closely adjacent the planar manifold and within the temperature-controlled zone, and one or more fluid-handling functional devices attached to the pneumatic manifold for fluid-tight communication with respective internal etched channels provided within in the planar pneumatic manifold.

Abstract: A connectorized capillary and in-line flow cell system which greatly expedites the construction of capillary zone electrophoresis (CZE) and other separation instrumentation. A capillary is mounted within a cavity formed in a body, and a mechanical fastener is positioned about the body. The inner diameter of the fastener is less than the outer diameter of the body, so that the connector may be firmly coupled to any system component having a corresponding portion adapted to accept the fastener. The connectorized capillaries thus permit permanent or semi-permanent attachment to various in-line flow cell devices such as detectors, valves, buffer reservoirs and the like. For example, an in-line conductivity detector is assembled by connecting a conductivity meter to the opposing ends of the flow cell body. Annular sensing surfaces can also be provided within the cell.

Abstract: A vacuum degassing and solvent delivery apparatus for those solvents being utilized in high pressure liquid chromatographic operations and/or applications. The degassing and delivery apparatus of the present invention is designed for attachment directly to a solvent reservoir, such as a bottle having a threaded neck portion. The arrangement facilitates ease of installation and removal of the vacuum degassing, recycling and delivery apparatus so as to accommodate a variety of installation applications and requirements. The solvent degassing system of the present invention further includes the utilization of an atmospheric impermeable composite tubing structure which is effective for isolating fluids from atmospheric contamination during transport.

Abstract: To supply supercritical fluid to an automatic supercritical fluid extractor and collect extract from the extractor, sample holding cartridges are lifted one by one in series by an elevator plug into a pressure chamber. An inlet at the top of the cartridge engages a pressure vessel inlet for the extractant so that extractant flows into the cartridge and into the space between the cartridge and inner walls of the pressure chamber. The outlets from the cartridge and pressure vessel communicate with the collector and exhaust through passageways in the plug. The plug has cleaning ports for cleaning seals and the outlet from the cartridge flows past the seals. The collector lifts vials into place and can precool the collection solvent, and later as part of the collection procedure, heat and pressurize the collector.

Abstract: Conventionally, the mass spectrometer unit is placed beside the gas chromatograph unit when the gas chromatograph unit is coupled with a mass spectrometer unit, whereas the normal detector is placed on the top of the gas chromatograph unit when it is coupled with a normal detector. This requires different structure of the gas chromatograph unit. In the gas chromatograph/mass spectrometer (GC/MS) system of the present invention that uses a suitably modified and re-designed mass spectrometer, the mass spectrometer unit is mounted on the top of the casing of the gas chromatograph unit. Thus a common gas chromatograph unit can be used whether it is coupled with a normal detector or with a mass spectrometer unit. Another advantage of the GC/MS system of the present invention is that it occupies less table-top or floor space.

Abstract: A preparatory supercritical extraction cartridge includes a chamber for sample having a volume in the range of 20 cubic centimeters to 2,000 cubic centimeters. An inlet and an outlet are fastened to the cartridge walls by threads and sealed to said cartridge walls With spring loaded seals so that they can be removed with a torque requirement of less than 35 pound inches. Inlet and outlet tubing are fastened to the inlet and outlet by quick release connectors.

Abstract: A microcolumnar analytical apparatus having a flow gating interface system for interfacing a first microcolumn and a second microcolumn is provided. The apparatus includes a flow gating interface, a first fluid conduit (e.g. a liquid chromatograph microcolumn) of a fluid sample, a flush liquid supplier, and a second fluid conduit (e.g. a capillary electrophoresis microcolumn) for analysis of the effluent fluid sample from the first fluid conduit. The flow gating interface includes a first microcolumnar section, a second microcolumnar section, and a channel. The channel, having an inwardly facing wall, encloses at least a portion each of the first microcolumnar section and the second microcolumnar section for conducting a flush fluid flow past the outlet end of the first microcolumnar section and the inlet end of the second microcolumnar section.

Abstract: A pumping system for continuously delivering fluid at a selected flow rate to a receiving system. The system includes at least a first and a second pumping unit, each of the individual units comprises a syringe and a valve. The syringe comprises a piston and a piston actuator, cylinder, and pressure sensor. The valve comprises a positively-actuated zero switching volume valve and valve actuator. The first and second pumping units are in fluid communication with one another and are capable of independent actuation. The individual valves are arranged to isolate either the first syringe or the second syringe, respectively, from the receiving system while at least one of the syringes remains in fluid communication with the receiving system whereby system pressure can be continuously monitored and the selected system flow rate maintained.

Abstract: A detachable column cartridge for a gas chromatograph is disclosed. The cartridge column contains analytical and reference columns, a heater and a thermocouple, and connects via detachable connectors to a base unit containing an injector, a detector and other components normally found in gas chromatographs. The cartridge arrangement permits a substitute column to be connected to the base unit easily, in the field, when different gases are to be separated and analyzed. Also included are specific connectors for detachably connecting the columns with capillary tubes in the base unit of the gas chromatograph.

Abstract: A casing structure for chromatograph having a plurality of casings respectively installing at least a separating column, a sample inducing portion and/or a detector portion of the chromatograph and the casings are vertically stacked one on another or horizontally juxtaposed one to another. The casing structure further comprises a passage for installing reagent feed pipes therein, and the passage is respectively provided in respective side portions of the casing for communicating with that of another casing when in the stacked state or in the juxtaposed state, and has an inner hole at an inner side thereof for connecting the reagent feed pipes to a pipe connecting portion arranged in the casings, and the passage has a cover at an outer side thereof for being opened outside of the casing.

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 capillary column connector assembly includes a pair of body members fabricated from a resilient, inert ceramic having high compressive strength. Each body member has an inwardly tapering longitudinal throughbore within which the end of a capillary column can be inserted by press-fitting. A split sleeve holds the two body members in mutually facing alignment with inner end surfaces in compressed mutual contact. The inner end surfaces are slightly radiussed in order to deform upon compression and provide a fluid-tight seal surrounding the junction between the inner ends of the longitudinal bores, thereby eliminating the need for any separate sealing gasket.A mechanical assembly comprising an inner spool, an outer housing, a spring, and a bearing-mounted support provide axial compression forces tending to urge the ceramic body members into mutual facing contact with the radiussed surfaces deformed.

Abstract: Apparatus and method for on-line coupled liquid chromatography and gas chromatography analysis. The system includes a high-volume, liquid vaporizing chamber, or interface capillary tube which allows injection of a substantial volume of sample-carrying eluent and concentrates bands, obviating adverse effects on the resolution or peak shape of the components of interest. The vaporizing chamber is interposed between a packed or wall-coated open tubular capillary liquid chromatographic column and a capillary gas chromatographic column. The capillary liquid chromatographic column permits the use of small volumes of eluent and reduced flow rates.

Abstract: A connectorized capillary and in-line flow cell system which greatly expedites the construction of capillary zone electrophoresis (CZE) and other separation instrumentation. A capillary is mounted within a cavity formed in a body, and a mechanical fastener is positioned about the body. The inner diameter of the fastener is less than the outer diameter of the body, so that the connector may be firmly coupled to any system component having a corresponding portion adapted to accept the fastener. The connectorized capillaries thus permit permanent or semi-permanent attachment to various in-line flow cell devices such as detectors, valves, buffer reservoirs and the like. For example, an in-line conductivity detector is assembled by connecting a conductivity meter to the opposing ends of the flow cell body. Annular sensing surfaces can also be provided within the cell.

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: The invention relates to a filter for cleaning gases, provided with a quick-change coupling having an inlet and an outlet channel, and a hollow filter material housing filled with filter material through which, in operation, the gas to be cleaned flows. According to the invention, the filter material housing and the quick-change coupling are manufactured from materials that do not react with the gases to be cleaned and which do not release any substances during operation. The filter material housing may for instance be manufactured from glass and the quick-change coupling from stainless steel.

Abstract: An improved axial flow chromatography column for separations dependent upon bed depth, such as size exclusion and where changes of column volume necessitate bed height adjustments. The improvements include a snap-action lever or a collet arrangement which permits quick and easy movement of the bed adjuster; a flush seal assembly at the outlet frit and a V-shaped seal in the bed adjuster which obviates dead volume gap of conventional O-ring seals; lens-shaped frits convex on the inlet and outlet sides provide for uniform flow through the column, and the access ports eliminate the contamination problem by providing easy access for cleaning and aspiration of liquid; and a combined inlet tube and adjuster tube assembly eliminates the need for threaded components which make sanitation difficult.

Abstract: An apparatus for sample concentration for gas chromatography and mass spectrometry for analysis for volatile organic compounds, including a hollow differential pressure switch to switch sample flow non-mechanically, and so that the gas chromatograph and apparatus may be used with different sample levels of volatile organic compounds by changing the timing and temperature parameters by changing the flow non-mechanically.

Abstract: An improved liquid filtering assembly used in applications such as filtering solvents for use in a liquid chromatography system. The filter assembly uses a filter cup having a large surface area which can be quickly removed and changed. The filter assembly also allows for the liquid to be drawn close to the bottom of the liquid reservoir. The filter assembly includes a coupling nut into which the tubing is secured on one side and an expansion member is secured on the other side. A seal ring is located around a portion of the expansion member. The expansion member urges the seal ring against the interior surface of the filter cup to secure the filter cup to the filter assembly. When the filter cup becomes clogged, the expansion member can be loosened to allow an operator to remove the clogged filter cup, replace it with a new filter cup, and then tighten the expansion member. Thus, the filter assembly can be reused simply by replacing the filter cup.

Abstract: This invention relates to a chromatographic column with a separation column which is equipped on at least one side with an end threading mechanism for connecting a capillary, a precolumn, or another separation column, whereby the end threading mechanism has a support nut surrounding the column tube and a coupling nut, and the support nut is supported towards the corresponding end of the separation column at a stop part which is held in a recess at the separation column wherein the column has several axially consecutive recesses.

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 detachable column cartridge for a gas chromatograph is disclosed. The cartridge column contains analytical and reference columns, a heater and a thermocouple, and connects via detachable connectors to a base unit containing an injector, a detector and other components normally found in gas chromatographs. The cartridge arrangement permits a substitute column to be connected to the base unit easily, in the field, when different gases are to be separated and analyzed.

Abstract: An apparatus and a method providing an open-split interface between a gas chromatograph and a mass spectrometer for delivering a substantially solvent free sample material from the gas chromatograph to the mass spectrometer. The apparatus has a junction having an inlet to receive a gas chromatograph effluent. An inert auxiliary fluid such as helium supplied through a port is used to scavenge the solvent rich effluent to atmosphere. A transfer member disposed partially within the junction is initially positioned at a first position to accomplish the aforementioned scavenging action. The transfer member is then repositioned to a second position to direct the substantially solvent free sample to the mass spectrometer for a qualitative and a quantitative analysis.