Agilent Technologies, Inc.

Hewlett-packard Company

Other

Matthew Spangler Klee

Bruce Douglas Quimby

Paul C Dryden

Wesley Miles Norman

Leonid M Blumberg

Elmer A Axelson

Mu Zou Wang

Michael Q Thompson

Philip Leigh Wylie

James D McCurry

Lawrence John Gajdos

William James Emmons

A non-seizing taper used for purged capillary tubing connections in gas chromatography that stops capillary tubing at a predictable position within the taper during installation and maintains space for gas to flow past the capillary tubing. The disclosed taper is an improved component of commonly used purged devices such as inlet liners and purged unions. The arresting aspect of the taper simplifies the process of capillary tubing installation while ensuring that the tubing will reproducibly be positioned in the taper. One or more features of the taper prevent tubing from seizing within the taper so that the devices can be reused and ensure that there is open space for a portion of gas to flow around and past the tubing. The angle of the taper, the dimensions of the taper, and the nature of the features within the taper can be adjusted to meet specific performance, usability and/or manufacturability requirements.

Non-seizing tapers for use in purged connections of capillary tubing used in gas chromatography

A detector in a gas chromatograph includes a detector inlet configured to receive a chromatographic column, the chromatographic column having a column entrance and a column exit, the column exit coupled to the detector inlet, a restriction integrated within the detector, the restriction located to receive an output of the chromatographic column, at least one pressure regulated gas source provided for normal gas chromatograph operation and arranged to provide at least one gas to a location between the integrated restriction and the column exit, and a backflush controller coupled to the pressure regulated gas source, the backflush controller configured to control a pressure differential between the column exit and the column entrance such that the at least one gas backflushes the chromatographic column when a pressure at the column exit exceeds a pressure at the column entrance.

System for integrated backflush in a gas chromatograph

A system for controlling fluid flow comprises a first fluid conduit having a length, an inner diameter, an input pressure and an output pressure, and a second fluid conduit having a length, an inner diameter, an input pressure and an output pressure where the output pressure of the first fluid conduit is the input pressure of the second fluid conduit. The system also comprises a pressure sensor configured to determine the output pressure of the first fluid conduit, and a controller configured to control the output pressure of the first fluid conduit, thereby establishing a desired fluid flow through the second fluid conduit based on the length of the second fluid conduit, the inner diameter of the second fluid conduit, the temperature of the second fluid conduit and the type of fluid flowing in the second fluid conduit.

System and method for controlling fluid flow

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.

Seal for gas chromatography

The invention provides a low mass and size thermal focusing device for a gas phase analytical device. The device has two or more plates bonded together. The device also has at least one channel with an entrance and exit is formed within allowing ingress and egress of a gas stream. The device also has a temperature reduction module in thermal contact with at least one plate of the device. Thermal focusing devices with additional plates and/or channels are also disclosed.

Focusing device based on bonded plate structures

A data manipulation method to make local chromatography data more usable and comparable to a reference. The method provides time axis correction to better match local data to a reference of the same time scale, time axis transformation to correspond more directly to a reference based on a different time scale, and response axis correction to better match a reference of the same or different response scale, while maintaining the original peak areas. The method may be used along or concurrently with other data manipulation technique to facilitate operations such as searching, matching, visual comparison, mathematical manipulation, and pattern recognition of chromatographic data.

Method of matching retention times among multiple chromatographic system

A method applies retention-time locking to the retention times and/or the column(s) void times of a target analyte(s) being eluted thru a multidimensional gas chromatography system. Retention time locking is applied to both standard and comprehensive multidimensional gas chromatography via the steps of adjusting column(s) head pressure in a locking multidimensional gas chromatograph system such that the measured retention times and/or void times match the known accepted. Retention time locking may be applied to either or both of the columns in a multidimensional gas chromatography system. Additionally, if the multidimensional system contains more than two columns in series, retention time locking can be applied to any or all of the columns as required.

Retention-time locked comprehensive multidimensional gas chromatography

A preferred method for identifying analytes of samples by utilizing chemometric analysis for interpreting chromatographic data obtained under locked conditions includes the steps of: (1) providing a locking GC system which includes a column operated at a column head pressure; (2) adjusting the column head pressure of the locking GC system so that a column void time of the column in the locking GC system, when a known analyte is eluted therethrough, is matched with the column void time of the column in a reference GC system, when the known analyte is eluted therethrough; (3) analyzing the sample with the locking GC system so that chromatographic data corresponding to the sample is compiled, and; (4) performing chemometric analysis on the chromatographic data.

Methods for sample identification using pattern recognition under locked conditions

Methods of separating and classifying the relative amounts of two or more classes of hydrocarbon molecules in a sample are disclosed wherein an input stream comprising a mobile phase and the sample is injected into a chromatographic column, and an effluent stream exiting a chromatographic column is split into a first effluent stream and a second effluent stream. The mass of carbon in each of the classes of hydrocarbons in the first effluent stream is determined, preferably using a flame ionization detector, and the second effluent stream is directed through a variable restrictor, allowing the pressure and mass flow rate of the input stream to be independently controlled and improved results obtained. In a preferred embodiment the present invention also includes identifying the hydrocarbon molecules in the second effluent stream in order to verify the analysis or provide additional data, preferably by using an ultraviolet detector. The present invention is most preferably used to analyze the aromatic hydrocarbons in a sample of diesel fuel.

Hydrocarbon class separation and quantitation by split column effluent analysis

A method for identifying analytes of interest by referencing to a retention factor database corresponding to a plurality of identified analytes that is independent of column dimensions and carrier gas type while dependent upon stationary phase type ratio and a relative temperature program. The retention factor database is generated on a reference GC system in which the column head pressure is adjusted to ensure high reproducibility of retention times by locking the column void time and/or the retention time of an identified analyte to a specific value such that accurate retention factors (k) can be calculated in accordance with the formula: ##EQU1## where VT is the void time of the column having a specified stationary phase and phase coating installed in a GC system operating in accordance to a specified temperature program (where time is expressed in units of column void time).

Retention factor database

The invention provides a method for automated matching of retention times obtained using a known chromatographic method having a defined set of column parameters and operating parameters to the retention times obtained using a new chromatographic method having a new set of column parameters, wherein the retention times of components separated in accordance with the new chromatographic method are matched to the retention times set forth in the known chromatographic methods. A procedure is described to adjust head pressure to compensate for differences in a new versus the original column, carrier gas, and column outlet pressure of the known method.

Automated retention time locking

The invention provides a method for developing a retention time database of identified analytes and their respective retention times in a reference Gas Chromatograph (GC) system under locked conditions for identification of unknown analytes of interest eluting from any GC system locked to the retention time database and may also be employed in combination with selective detection and or method translation for enhanced certainty of identification.

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Wilmington, DE, United States of America

Matthew Spangler Klee