Abstract: Chromatographic system includes a split/splitless injection port operatively connected to an inlet line for receiving the regulated carrier gas flow, a separation column for receiving at least a portion of the mixture as a column flow, and a split vent line and a septum purge line for outputting respectively a split flow and a septum purge flow. A forward device driver operatively connected to a respective fluid controller controls fluid flow in the inlet line and a back device driver operatively connected to a respective fluid controller controls fluid pressure in the split line. A setpoint controller provides first and second setpoint control output values to a configuration module, which selectably configures the provision of each of the first and second setpoint control output values to a selected one of the forward and back device drivers according to the selection of a split or splitless injection mode.

Abstract: A liquid chromatography column well-suited for in situ sterilization effected by washing with a sterilization solution. In a preferred embodiment, the column comprises a liquid chromatography tube packed with a liquid chromatography resin. A piston assembly is mounted within the liquid chromatography tube towards the upper end thereof, the piston assembly including an upper portion and a lower portion, the lower portion being shaped to include a fluid distribution channel and a downwardly-extending collar, the downwardly-extending collar including an annular slot and defining an orifice in fluid communication with the fluid distribution channel.

Abstract: An improvement to a sample concentrator apparatus for extracting and concentrating trace organic components from an aqueous sample for subsequent analysis; and a method for concentrating trace organics.

Abstract: A gas chromatograph for operation selectably in both split mode and splitless wide bore injection mode includes a capillary column, a sample injection chamber at the inlet of the column, a three-way valve, a first piping line connected between one of the two outlets of the three-way valve and the sample injection chamber, a split line connected to the sample injection chamber immediately upstream of the inlet of the column for discharging therethrough a portion of a gas being sent out from the sample injection chamber, a second piping line connected between the other of the outlets of the three-way valve and the split line, and a third piping line connected between the first and second piping lines. By properly controlling the total carrier gas flow rate and the column inlet pressure, the split ratio can be controlled easily. By varying the split ratio appropriately during an analysis, the amount of the carrier gas to be wasted in the case of a split mode of operation can be significantly reduced.

Abstract: A step-down nozzle for the even distribution of fluids at the interface between phases in a column or cell accommodating a plug flow operation is structured with an internal flow channel of recursive configuration.

Abstract: Method and apparatus for gas chromatography/mass spectroscopy including a retention gap, a capillary gas chromatography column and a mass spectrometer, the improvement being a valve that facilitates temporarily venting the carrier gas from between the retention gap and the capillary gas chromatography column immediately after the injection of a sample. The valve also facilitates an alternate flow of carrier gas into the mass spectrometer during the venting operation.

Abstract: In a chromatography column one or more of the end plates defining the column are provided with specially designed lands and grooves to more effectively uniformly distribute the input liquid over the column cross-sectional area and thus improve the separation of sample components, the upper end wall of the column being adjustably positionable to vary the axial length of the column by means of novel structure including readily releasable speed nuts engageable with externally threaded rods, the seal between the movable upper plate and the column wall being so designed as to minimize dead space and thus further increase separating power, and the structure for adjustably positioning said top wall includes elements enabling that structure and the top wall connected thereto to be conveniently supported in inverted condition when separated from the remainder of the column structure.

Abstract: A gas chromatography system in which prefocusing of a sample analyte is provided through the use of an adsorbent coated porous layer open tubular trap tube. Through the use of an adsorbent coated collection device low boiling point components can be successfully trapped for preconcentration and injection at temperatures well above that necessary when employing conventional cryo-focusing.

Abstract: In a method for extracting volatile substances from a vaporized liquid in which the vaporized liquid is withdrawn from an extraction chamber, a method of producing the vaporized liquid. The method includes the steps of introducing a carrier gas into the extraction chamber to form a vapor space, and spraying a liquid into the vapor space to form a vaporized liquid. An apparatus for practicing the method includes an extraction chamber in fluid communication with a liquid specimen source, and a liquid injection arrangement extending into the extraction chamber for spraying the liquid from the liquid specimen source in the vapor space to form a vaporized liquid. A carrier gas supply arrangement is provided adjacent to the extraction chamber for introducing carrier gas into the chamber to form a vapor space. The apparatus may further include a specimen chamber for collecting a predetermined amount of liquid prior to spraying.

Abstract: An injector with a vaporization chamber for gas chromatographic apparatus includes a heater to heat the chamber and a pierceable septum to seal an end of the chamber. At least a heat conducting element is removably mounted between the septum and the heater. One or more elements are positioned adjacent to the septum and are in fluid communication with a source of carrier gas and a discharge outlet. The elements define paths with forced run for washing the septum and for feeding the vaporization chamber.

Abstract: A water management system removes water vapor from the analyte slug that is desorbed from the trap. The water management system includes a device having a passage through which the volatile organic chemicals and water pass, the passage being designed to remove water vapor by swirling action on the stream. The amount of water removed is more than can be accounted for by simple condensation. The invention also includes the adjustment of the temperature of the water management device during the sample concentration cycle to prevent undesired condensation prior to desorption.

Abstract: Apparatus and methods are provided for using a detector designed for use with liquids to detect resolved analytes in an effluent stream from a gas chromatography instrument. The gaseous stream is entrained by a flowing liquid solvent, and at least a portion of the analytes are transferred from the gas phase to the liquid phase. The liquid solvent containing the analytes is then conveyed to a detector designed for liquid analysis. Thus, the present invention gives the analyst more options for detecting an analyte or a group of analytes, thereby providing greater flexibility in optimizing the sensitivity or selectivity of the analysis. Furthermore, the present invention allows gaseous effluents to be analyzed by detectors which more readily permit sample recovery than the detectors currently being used to analyze gaseous effluents.