Abstract: A device and process to measure the water content of a material or the water permeability of a membrane by stably humidifying a carrier gas stream and passing it through calcium carbide to convert the water content of the stream to acetylene, then producing a spectrographic or equivalent trace establishing the stable acetylene value of the carrier gas, then passing carrier gas into contact with the material whose water content is to be measured to evaporate water from it and passing the carrier gas through the calcium carbide whereby the water content of the material is represented by the area between the stable acetylene value and the spectrographic trace caused by the added water.

Abstract: In a chemical analysis system a sample liquid is passed through a non-wetting porous membrane from a reservoir of sample liquid to a flowing stream of diluent which is constantly flowing when the sample liquid penetrates the membrane under positive pressure differential from the sample side of the membrane. The pressure differential is suitably obtained both by means for exerting pressure on the sample liquids as for example on a stream of sample liquid on the entry side of the membrane as well as a reduction in pressure on the exit side of the membrane. The passage of the sample liquid through the non-wetting porous membrane requires a minimum liquid entry pressure differential across the membrane to cause enough penetration to give a sample liquid which provides in an analyzed diluent stream a detectable presence of the sample liquid in an analytical detector receiving and measuring the stream.

Abstract: A system for detecting analytes in air or aqueous systems includes a permeation absorption preconcentrator sampler for the analytes and analyte detectors. The preconcentrator has an inner fluid-permeable container into which a charge of analyte-sorbing liquid is intermittently injected, and a fluid-impermeable outer container. The sample is passed through the outer container and around the inner container for trapping and preconcentrating the analyte in the sorbing liquid. The analyte can be detected photometrically by injecting with the sorbing material a reagent which reacts with the analyte to produce a characteristic color or fluorescence which is detected by illuminating the contents of the inner container with a light source and measuring the absorbed or emitted light, or by producing a characteristic chemiluminescence which can be detected by a suitable light sensor. The analyte can also be detected amperometrically.

Abstract: An apparatus to measure the concentration of a constituent of a solution containing dissolved gas includes a conduit connectable to a source of the solution. Flow controllers are provided on the conduit, selectively to permit the flow of the solution in the conduit. Pressure regulators are also provided on the conduit to control the pressure of the solution in the conduit, and maintain the pressure in the conduit means at a level sufficiently high to prevent gassification of dissolved gas in the solution, thereby to prevent foaming in the conduit. A gas chromatographic analyser (GCA) is in communication with the conduit via a sampling valve, to permit the flow of discrete samples of solution into the GCA for analysis. The interior of the GCA is maintainable at the same pressure as in the conduit.

Abstract: A process for determining the polarity of a crude oil or heavy fraction thereof in which the retention times are measured when a series of substances is contacted with a chromatographic column of crude oil, the retention times are measured when these substances are contacted with a chromatographic column of a second substance usually non-polar and the relative polarity of the oil determined from the times measured.

Abstract: A portable system for analyzing a fluid sample includes a small, portable, low-pressure and low-power chromatographic analyzer and a chemical parameter spectrometry monitor including an array of sensors for detecting, identifying and measuring the concentrations of a variety of components in the eluent from the chromatographic analyzer. The monitor includes one or more operating condition controllers which may be used to change one or more of the operating conditions during exposure of the sensors to the eluent from the chromatography analyzer to form a response pattern which is then compared with a library of previously established patterns. Gas and liquid chromatographic embodiments are disclosed. In the gas embodiment, the operating condition controllers include heated filaments which may convert electrochemically inactive components to electrochemically active products. In the liquid chromatography embodiment, low-power, liquid-phase equivalents of heated filaments are used with appropriate sensors.

Abstract: Upstream and downstream flow dividers are connected in series between a sample dispenser and a gas chromatograph separation column. The downstream flow divider is connected to a source of carrier gas, and the system can be backflushed with carrier gas to remove residual quantities of sample material and elute the sample.

Abstract: A method for temperature programmed capillary column gas chromatography characterized in that carrier gas is flowed in an amount greater than that under normal separation conditions for a term starting from before injection of a sample or immediately after the injection and ending at any time point from immediately after a solvent in the sample commences to enter into a column to the solvent finishing passing through the column. The invention is also apparatus for the above method characterized in that the apparatus has two flow paths for carrier gas which, for example, join to one flow path before a sample injection device, and one of the flow paths has a valve which can rapidly stop or decrease the flow of the carrier gas in that flow path.

Abstract: A method for determining sorption isotherms of food by inverse chromatography comprising the steps of passing a mobile phase having a known solute concentration and at a known flow rate through a stationary phase comprising a known mass of food at a known temperature, measuring the concentration of solute in the mobile phase leaving the food, determining the amount of solute which has entered the food at selected intervals from the known concentration, known flow rate and time elapsed from the beginning of the passing step, determining the amount of solute which has passed downstream of the food at selected intervals from the measurement of the concentration of the solute, and determining the amount of solute at selected intervals taken up by the food from the difference in the amounts determined above.

Abstract: A gas chromatography (GC) system includes a primary complete, independently-operable, self-contained GC system and a secondary, dependently-operable GC system. The primary and secondary systems have two independently controlled GC ovens. Injectors and detectors are supported by heater blocks or ovens mounted on the respective GC ovens and are connected to the electrical and pneumatic controls of the primary GC system. The injectors and detectors of the secondary GC system share operation of the primary GC system. GC columns can be mounted in each oven and operated completely independently or dependently in different ways. A separate power supply for the secondary oven is connectable to a separate circuit or power line in the user environment.

Abstract: A liquid sample to be analyzed is subjected to a vaporizing step. The vaporized components are submitted to a first separation stage by introducing said components into a packed chromatography column and flowing carrier gas through said column. The effluent of the first stage is passed through a flow dividing chamber. A second separation stage is performed by passing the effluent of the flow dividing chamber to a capillary chromatography column and flowing carrier gas therethrough. After a predetermined period of time, flushing gas is introduced through the flow dividing chamber and flowed through the first-stage packed column in a direction opposite to the original direction of flow while the direction of flow remains unchanged in the capillary column.

Abstract: A gas analysis apparatus including a sorption bed and a receiver normally spaced apart from the sorption bed. A given flow path is defined between the sorption bed and the receiver for directing a gas to be analyzed across the sorption bed for adsorption thereby in an adsorption mode of operation of the apparatus. A drive relatively moves the sorption bed and the receiver closer together from their spaced apart condition to produce a volume reduction of the defined, given flow path across the sorption bed in a desorption mode of operation of the apparatus. A heater selectively heats the sorption bed to desorb the adsorbed gas from the bed into the volume reduced flow path. A gas analyzer is connected to the receiver for analyzing the desorbed gas.

Abstract: This invention concerns a method and a device to perform the adjustment of the cooling temperature of a trap for samples in an apparatus of gas chromatographic analysis. The method according to the invention is characterized in that the cooling fluid flow fed to the trap is adjusted by varying the vacuum caused by a suction device downstream the trap, which is capable of sucking the cooling fluid from a vessel upstream the trap itself.The device according to the invention is characterized in that it comprises a suction means placed downstream the trap and connected by means of a first duct to an end of the trap itself, the other end of the trap being connected, by a second duct, to a vessel containing the refrigerating fluid.

Abstract: A gas chromatography system having a chromatography column, a detector for analyzing sample components with a detection chamber connected to the column outlet, and a switching assembly for selectively alternately filling the detector chamber with carrier gas for a base line measurement and with effluent for analysis. The switching assembly includes a gas chamber connected to the detector chamber, a source of carrier gas and hot wire filament for selectively heating gas in the gas chamber to cause the carrier to be expelled from the gas chamber to fill the detection chamber for a base line measurement and for cooling gas in the gas chamber to withdraw the carrier gas from the detection chamber so as to draw effluent from the column outlet to thereby fill the detection chamber for an analytical measurement.

Abstract: An apparatus for taking samples by thermal desorption of compounds that are adsorbed on solid adsorbents contained in a sample tube. An injector has a recess for accommodating the sample tube and a connection for a capillary column of a gas chromatograph. The compounds are desorbed into such capillary column by means of a stream of carrier gas passing through the sample tube. An injector extension is fastened to the injector and has a recess for accommodating the sample tube. The recess of the injector extension is flush with the recess of the injector. A push rod is guidable in the injector extension for pushing the sample tube from a position in the injector extension into a position within the injector. A carrier gas inlet communicates with the recess in the injector extension for admitting a carrier gas therein. A plug is disposed at an end of the push rod for gripping the sample tube. The plug includes a bore for effecting communication between the carrier gas inlet and the interior of the sample tube.

Abstract: An assembly of nonreactive material receives a sample of material to be analyzed which is then placed in an environmentally controlled pyrolysis chamber. As the sample is selectively heated, an inert carrier gas is admitted to the chamber to wash the gases from the sample through trap and splitter assemblies where a portion of the sample gas is tapped off by a capillary column. The temperature of the gas in the capillary column is controlled as known makeup gases are added prior to passing through a detector, such as a flame ionization detector, to determine the components of the sample gas. The capillary tube can also be coated with an apolar liquid phase separation material.

Abstract: Coated carbon composite parts to be tested for oxidation resistance are heated in a closed oven filled with an oxidizing atmosphere. During the heat cycle the carbon dioxide content of the oven atmosphere is measured by an analyzer such as a gas chromatograph. These measurements on the amount of CO.sub.2 emitted by the part provide information on the onset of oxidative failure. It forms a nondestructive test when detection of excessive carbon dioxide concentration is used to reduce the temperature and flood the oven with inert gas so the part may be saved and reprocessed. This technique can be combined with conventional weight measurements before and after oxidation to identify the part constituent, carbon composite or protective coating, that failed.

Abstract: A linear equation which infers elution time in a gas chromatograph as a function of temperature is assigned to a chemical compound. The linear equation is useful in constructing a computer data base which contains a long list of chemical compounds, a list of chromatographs each having a separation column containing a different adsorbent material, and a long list of linear equations associating each chemical compound with each chromatograph. The data base, which is arranged for computer searching, aids researchers in gas chromatography by automating a systematic search for optimum combination of separation columns and operating parameters.

Abstract: Method for monitoring changes in contaminant concentration levels between a feedwater inlet and a steam outlet in a steam generating system and system for detecting sources of contaminants in a steam generating system. The method includes a reliable means for detecting organic contaminants, chlorides, sulfides and nitrides. The invention also includes a method for determining whether the organic compounds are chlorinated, sulfinated or nitrogenated. The method is based on monitoring of ion concentration levels and cation exchanged conductivities in samples of feedwater and steam.

Abstract: The disclosure relates to improvements in the art of gas chromatography, and gas chromatographs containing a detector operated on the thermal conductivity principle. In the conventional gas chromatograph, a pair of resistance filaments constitutes an opposite arm of a Wheatstone bridge, and each of two pairs of filaments provides a reference side and a measuring side, respectively, across which a carrier gas can be flowed and the bridge balanced. A moisture-containing sample can be input and transported via carrier gas through a circuit to a substrate filled column and the moisture and other components of the sample separated according to their different affinities for the column substrate. The sample constituents elute from the column in characteristic sequence as elution bands diluted with carrier gas.

Abstract: A continuous air monitoring apparatus utilizes a solid sorbent preconcentrator to concentrate airborne sorbent compounds for gas chromatographic analysis. Direct connection between the preconcentrator and gas chromatographic column allows direct desorption of the compounds into the column with minimal dead space. Temperature control on the column allows sharp chromatographic peaks to be attained with cryogenic focussing.

Abstract: An interface generally useful for liquid chromotography systems and methods is provided for the separation of an analyte of interest from a liquid solvent. The interface provides for separation and collection of solvent and the analyte of interest in a gaseous molecular state. In this manner, the ability to detect, identify, and quantify the analyte of interest using a variety of specific and non-specific detectors is made possible.

Abstract: The invention concerns a method and an equipment for the simulated distillation, by means of gas chromatography, of petroleum products, capable of characterizing also high boiling products, exceeding C55, over 600.degree. C. TBP. A chromatograph is used with a capillary column having a length less than or equal to 10 m, containing an immobilized non polar polydimethylsilicon gum stationary phase with a film thickness less than or equal to 0.2 .mu.m. The sample is introduced through a non vaporizing direct cold on-column injection and the eluted sample is detected by means of a FID detector. The column oven is operated in temperature programming conditions up to temperatures exceeding 400.degree. (up to 430.degree.-450.degree. C.).

Abstract: Apparatus for detecting gas in a sample gas in a carrier gas stream and including a windowless ionization detector having a pulsed power supply which is switchable at a rate which provides a pulse period shorter that the transit time of ions to be detected to the collector electrode of an ionization chamber of the detector. Switching allows any signal due to ion detection to be separated from background noise due to other effects in the chamber.

Abstract: A detection system for detecting the presence of predetermined compounds in a sample. The system comprises a sample injection means, a chromatographic column, a conversion means and one or more specific gas detectors. The conversion means transforms the column effluent to combustion products in the gas phase, after which those combustion products are transferred to the specific gas detectors. In one embodiment for detecting nitrogen compounds, the conversion means includes an oxygen-rich flame, a means to control the flame to have a temperature in the range 600.degree.-1700.degree. C., means to inject the column effluent into the flame, and an output port for transferring the flame effluent to a specific nitrogen detector.

Abstract: A device used in the determination of the quantitative composition of gases dissolved in the insulating oil of oil-insulated electrical apparatus wherein the device is capable of removing insulating oil samples and includes a pump arrangement for the extraction of the gases from the insulating oil sample by means of reduced pressure and for conveying it to an analytical section is disclosed. This device is intended to operate directly on the electrical apparatus to be investigated. This is achieved in that the device is constructed in a transportable manner and incorporates a peristaltically operating pump arrangement. This pump arrangement contains at least one peristaltic pump, whose inlet can be connected via an extraction vessel with the removal device and whose outlet can be connected optionally with the outside air or with a gas collecting vessel. The gases from the gas collecting vessel are analyzed in the analytical section.

Abstract: The invention concerns a method and an equipment for the simulated distillation, by means of gas chromatography, of petroleum products, capable of characterizing also high boiling products, exceeding C55, over 600 C TBP. A chromatograph is used with a capillary column having a length less than or equal to 10 m, containing an immobilized non polar polydimethylsilicon gum stationary phase with a film thickness less than or equal to 0.2 .mu.m. The sample is introduced through a non vaporizing direct cold on-column injection and the eluted sample is detected by means of a FID detector. The column oven is operated in temperature programming conditions up to temperatures exceeding 400 (up to 430-450 C.).

Abstract: A sorption/desorption gas analysis apparatus includes a sorption/desorption bed having a thin layer of sorption material fixed to an outside surface of a first and a second adjacent tapered bed element arranged in a mutually mating configuration. The bed elements are further arranged to be selectively moved with respect to each other to produce a first flow volume therebetween past the sorptive material during a sorption mode of operation and a second substantially smaller flow volume past the sorptive material during a desorption mode of operation. The sorption/desorption bed is used in the gas analysis apparatus by first exposing the sorption bed to an impinging flow of a sample gas containing the constituent of interest which is sorbed by the sorptive material in the sorption mode of operation.

Abstract: A gas-sample collection device provides for the matrix isolation of increased amounts of a sample material for spectrographic analysis from a gas chromatographic separation. The device includes an evacuated sample collection chamber containing a disc-like specular carousel having a generally circular lateral surface upon which the sample is deposited in an inert gas matrix for infrared (IR) spectral analysis. The evacuated sample chamber is mounted in a fixed manner and is coupled to and supports a rotating cryostatic coupler which, in turn, supports the specular carousel within the collection chamber. A rotational drive system connected to the cryostatic coupler provides for its rotational displacement as well as that of the sample collecting carousel. In addition, rotation of the cryostatic coupler effects vertical displacement of the carousel to permit the collection of an extended sample band in a helical configuration on the entire lateral surface of the carousel.

Abstract: A small volume electron capture detector has a cylindrical cell 120 inside which there is provided a generally funnel-shaped insert structure 130 having a cup-shaped section and a cylindrical section. The rims of the cup-shaped section nearly touch the inner walls of the cell 120 so as to separate the active volume from the areas at the top corners of the cell 120 which are not actively swept by the carrier gas, thus reducing the tailing of chromatographic peaks.

Abstract: A sample valve for solute modulated synchronous detection alternately directs into a detector a sample gas stream F.sub.1 which passes through a modulator cell and a reference gas stream F.sub.2 which passes through a balance cell. The sample valve is made of a symmetrically structured chamber with inlets and outlets. An ordinary valve causes a control gas to stream into the chamber alternately though one of two openings to exit openings of the chamber are synchronously opened and closed so that gas streams F.sub.1 and F.sub.2 are alternately led into the detector and out of the system.

Abstract: An electron capture detector for use with a capillary column is provided with a sample inlet comprising a tubular anode through which sample molecules and a make-up gas are introduced into the detector cell. The tubular anode has side ports for producing a plug-like flow inside the cell. The inner surface of the anode is protected by an insulating tube so that the capillary column can be extended to a point beyond the side ports without the fear of its electrical contact with the anode. This allows the sample molecules to flow nearly entirely in the center section of the cell. The peripheral regions of the cell where a radioactive foil is disposed is swept nearly entirely by the make-up gas entering the cell through the side ports. This has the effects of reducing sample dilution by the make-up gas and sample loss due to contact with the detector walls.

Abstract: A gas chromatographic method and apparatus are provided wherein a reservoir system including at least one reservoir is utilized to collect each component as it elutes from a chromatographic separation column. Immediately after collection of each component, a constant flow of carrier gas is allowed to pass into the reservoir system to carry each component to a detector. According to another aspect of the invention, a method is provided which employs a reference gas mixture in conjunction with the reservoir system to check calibration of a gas chromatography system.

Abstract: A gas chromatograph system is provided with an improved electrolytic conductivity cell (16) for detecting a selected material species in a fluid stream from conventional gas chromatograph (10, 12) having both gas and liquid phases. Planar electrodes (80, 82) are spaced by an insulator (84) and define borehole diameters (88, 90, 92) which enhance the generated signal-to-noise ratio by providing a short fluid transit time within the conductivity detecting volume compared with the effective time of the chromatographic event of interest. A pneumatic damper (108) may be further included to reduce generated system signal noise.

Abstract: An apparatus and process for the vacuum distillation of volatile organic pollutants contained in various environmental sample matrices, such as sediments, soils, water and fish is connected to a cryogenic concentrating means. The volatile organic pollutants in the sample are first separated from the water vapors in the mixture which emanates from a sample chamber by condensing the water vapors in a precooling trap. The volatile organic compounds are first condensed in a cryogenic concentration trap which is subsequently warmed to transfer the volatile organic vapors to a cryogenic focusing trap cooled to -196.degree. C. A series of manually activated or automatically solenoid activated valves controls passage of the various fluids through a conduit network selectively connecting the various cooling traps and the outlet of a sample chamber to one another. A cooled pump oil trap may be connected into the conduit network to condense pump oil vapors and thus prevent pump oil contamination of the apparatus.

Abstract: The present invention provides for on-site capture of carbonaceous gas at sea, for isotopic examination. A capture box is utilized to provide trapping, stripping and combustion of a gas stream to permit methane analysis.

Abstract: An apparatus for analyzing a sample with a supercritical fluid includes a fluid container containing as an extraction solvent a fluid obtained by compressing and liquefying a substance which is a gas at ambient temperature and atmospheric pressure. A pump is provided for drawing the fluid from its container through a suction line and delivering it through a delivery line, while the heads of the pump are cooled by a cooling device. An extraction mechanism is provided for bringing the fluid in a supercritical state into contact with the sample to be analyzed and extracting a specific component or components from the sample. A trapping mechanism is provided downstream of the extraction mechanism for collecting the extracted component or components from the fluid. An analyzing mechanism can be connected to the trapping mechanism by changeover valves for analyzing the collected component or components.

Abstract: A gas-sample collection device provides matrix isolation of individual gas bands from a gas chromatographic separation and for the spectroscopic analysis of the individual sample bands. The device includes a vacuum chamber containing a rotatably supported, specular carousel having at least one reflecting surface for holding a sample deposited thereon. A gas inlet is provided for depositing a mixture of sample and matrix material on the reflecting surface which is maintained at a sufficiently low temperature to cause solidification. A first parabolic mirror directs an incident beam of electromagnetic radiation, such as in the infrared (IR) spectrum, from a source onto the sample/matrix mixture while a second parabolic mirror directs a second beam of electromagnetic radiation reflected by the specular surface to an IR spectrometer for determining the absorption spectra of the sample material deposited on the reflecting surface.

Abstract: A gas chromatograph system is provided with an improved electrolytic conductivity cell (16) for detecting a selected material species in a fluid stream from conventional gas chromatograph (10, 12) having both gas and liquid phases. Planar electrodes (80, 82) are spaced by an insulator (84) and define borehole diameters (88, 90, 92) which enhance the generated signal-to-noise ratio by providing a short fluid transit time within the conductivity detecting volume compared with the effective time of the chromatographic event of interest. A pneumatic damper (108) may be further included to reduce generated system signal noise.

Abstract: The specification discloses an analyzer for determining the carbon, hydrogen, and nitrogen content of an organic material. The analyzer includes a vertically oriented, U-shaped furnace including a combustion chamber containing a crucible in which the sample is combusted into constituent gases and a reagent chamber containing a reagent through which the constituent gases must pass. A lance extends into the combustion chamber to guide the sample into the crucible and to direct oxygen onto the sample combusting in the crucible. The analyzer further includes an equilibration vessel and means for conveying the constituent gases to the vessel and past CO.sub.2 and H.sub.2 O infrared cells to monitor the products of combustion. Means are provided for conveying the equilibrated gases past the infrared cells to obtain readings relating to carbon and hydrogen content. A doser doses an aliquot of the equilibrated gas into a nitrogen measurement apparatus to obtain a reading relating to nitrogen content.

Abstract: A method and apparatus for determining the total amount of organic carbon in a sample comprising the successive steps of: (a) heating the sample in an inert atmosphere to a first temperature capable of cracking at least a fraction of the organic material contained in the sample; (b) measuring the amount of organic carbon contained in at least a fraction of the effluent resulting from this cracking; (c) heating the sample in an oxidizing atmosphere to a second temperature at most equal to the first temperature; (d) measuring the amount of organic carbon in the effluent produced by the oxidation of the organic material, and (e) deriving from the above measurements the total organic carbon content of the sample. In order to perform the method of the invention, there is also provided means for performing each of the successive steps. In a further refinement, the method also includes steps for determining the mineral carbon content so that the total carbon content of the sample can be determined.

Abstract: The invention relates to a modified-flame thermionic detector for gas chromatographs, of the type including a burner nozzle, an excitation electrode and a collecting electrode. The electrical connections of the nozzle and the excitation electrode can be changed at the operator's will, together with the spatial position of the excitation electrode with respect to the flame and the collector, to find out the presence of certain compounds, leaving all other conditions of analysis performance and detector supply unaltered. This allows obtaining chromatograms of unknown samples under different conditions of the detector configuration, to put into evidence the presence of certain compounds in the sample by comparing peaks of chromatograms obtained under said different operating conditions of the detector.

Abstract: A gas chromatography assembly has a substrate wafer with grooves and a valve seat etched therein. A plate cooperates with the wafer and the grooves to define gas channels: a carrier gas channel and a sample gas channel, each passing through the valve seat. A valve actuator is attached to the valve seat for controlling the flow of sample gas from the sample gas channel into the carrier gas channel. A pump is attached to the wafer and is connected to the sample gas channel. The pump cooperates with the valve actuator to inject sample gas from the sample gas channel into the carrier gas channel. A modular capillary tube and a detector are connected to the carrier gas channel to analyze the properties of the sample gas flowing in the carrier gas channel from the sample gas channel.

Abstract: A gas chromatographic apparatus is provided which comprises a gas chromatography column, a detector and an extended conduit between the column and the detector, the conduit providing means for flow of a gas so as to enable essentially complete elution of the gas from the column before the gas is detected by the detector. The apparatus can be adapted for use in an instrument for the elemental analysis of a sample for carbon, hydrogen, nitrogen and sulfur. The invention method includes the steps of introducing a sample in vapor form into a gas chromatography column, passing the sample through the column so as to separate at least one component of interest, passing the component of interest through a conduit to the detector so as to reach the detector after the essentially complete elution of the component of interest from the column.

Abstract: A flame detector analyzer of the type wherein a sample gas is introduced into a flame formed by burning a fuel gas in presence of a combustion supporting gas, comprises a background providing device for supplying a background component gas capable of emitting a characteristic spectrum having the same wave length as that of the characteristic spectrum of a measuring object component contained in the sample gas, the light spectrums emitted from the measuring object component and the background component gas being received and treated to be detected, thereby increasing the measuring accuracy for the measuring object component and improving the resolving power at a low concentration detection region.

Abstract: Samples of substances from sources of variable temperature and pressure are injected into a stream of fluid carrier, for example in chromatographic analysis, without bringing them into contact with moving parts. A stream of the substance is passed through a restriction to the junction of a vent and an injection limb each containing flow restrictions, and carrier fluid is fed alternatively upstream of those restrictions. By thermostatting the injection limb and appropriately selecting the various flow rates constant sized samples may be secured by switching the carrier fluid from the injection limb to the vent for constant times.

Abstract: A regenerator control system is disclosed which is particularly useful in connection with combustion promoted cracking catalysts. The air flow is controlled responsive to the temperature in the dilute phase, first in a direct mode when the amount of combustibles on the catalyst is at or above a set point and second in accordance with a reverse mode when the amount of combustibles is below such a set point. This versatile control system allows a safe operation of a regenerator under a variety of conditions.

Abstract: An electrochemical detector cell (10) and apparatus incorporating the cell (10) includes a first capillary (12) having an entrance (14) connected to an electrolyte source (30) and an exit (16). A second capillary (18) is connected to reactive gas source (32) and intersects the first capillary (12) at (22) to define a reaction zone (20) in the first capillary (12). A sensor electrode (24) is positioned in the first capillary (12) in the reaction zone (20). A third capillary (26) intersects the first capillary (12) within the reaction zone (20). A reference electrode (28) is positioned in the third capillary (26). The third capillary (26) is connected to a solution source (34). The electrodes (24) and (28) may be used for potentiometric measurements. A fourth capillary (38) intersects the first capillary between entrance (14) and intersection (22) of the first capillary (12) and the second capillary (18).

Abstract: A sensing apparatus and method for qualitatively and quantitatively analyzing small amounts of selected oxidizable gases in a carrier gas including the associated electronic circuitry is described. The apparatus preferably includes two semi-conductor type sensing elements in electrical parallel so that the difference in resistance of the two sensors can be detected, which can be of the N or P type and which decrease or increase in electrical resistance as a function of the concentration of an oxidizable gas. Also, a method for determining fruit maturity and ripeness by the detection of ethylene in the internal atmosphere of a fruit is described which preferably uses the apparatus with the semi-conductor type sensing elements, but can use other variable resistance type gas sensing means.

Abstract: To avoid the problem of instrumental drift encountered when using an open-split interface between a temperature-programmed gas-liquid chromatography column and a mass spectrometer, the inert gas supplied to the open-split interface and the interface itself are heated to a temperature above the maximum temperature attained by the chromatography column during the analysis.