A GC fitting for an inner tube of a heated transfer line of a gas chromatography interface probe, the fitting comprising a first section comprising a substantially cylindrical projection for fluid connection to a GC source in use, and a second section having a larger radius than the first section in at least one direction, the second section being provided with at least one flat.

A GC interface assembly for a heated transfer line of a gas chromatography interface probe, the heated transfer line comprising an inner tube and an outer tube, the GC interface assembly comprising: a GC fitting securable to said inner tube, the GC fitting comprising a first section comprising a substantially cylindrical projection for fluid connection to a GC source in use, and a second section having a larger radius than the first section in at least one direction, the second section being provided with at least one flat; and a GC end cap securable to an outer tube, the GC end cap comprising an aperture which slidably receives the second section of the GC fitting in use such that the GC fitting is substantially constrained to liner movement with respect to the GC end cap.

The disclosed system and method improve analysis of chemical samples for measurement of trace volatile chemicals, such as by Gas Chromatography (GC) and Gas Chromatography/Mass Spectrometry (GCMS). The system can include two traps in series, the first of which removes most of the unwanted water vapor, while the second trap preconcentrates the sample using a series of capillary columns of increasing adsorption strength. The sample can be backflushed from the second trap directly to a chemical analyzer without splitting which can maximize sensitivity. The system improves elimination of water vapor and fixed gases from the sample prior to analysis, resulting in detection limits as low as 0.001 PPBb. The second trap allows faster release of the sample upon injection to the chemical analyzer without additional focusing, and can be cleaned up faster when exposed to high concentration samples relative to packed traps.

A system for identifying and/or measuring a substance concentration in the exhaled breath of a patient (4), comprises a measurement apparatus (20) for performing an ion mobility spectrometry measurement of a sampling gas stream (A) obtained from the exhaled breath of the patient (4), the measurement apparatus (20) comprising a drift detector (22) and at least one gas circuit (23, 24) connected to the drift detector (22) for guiding an analytic gas stream (B), into which a sample of the sampling gas stream (A) is injectable, towards an inlet end (220) of the drift detector (22) and/or a drift gas stream (C) towards an outlet end (221) of the drift detector (22), wherein the at least one gas circuit (23, 24) comprises a molecular sieve filter (233, 241) comprising a filter material (26) for filtering the analytic gas stream (B) and/or the drift gas stream (C). Herein, the filter material (26) comprises the zeolite NaY.

A gas chromatography (GC) column system includes an insulation tubing, a metallic GC column disposed within the insulation tubing and having an outer diameter that is less than or equal to an inner diameter of the insulation tubing, a first electrode in contact with the metallic GC column, and a second electrode in contact with the metallic GC column on an opposite side of the insulation tubing from the first electrode. The metallic GC column may be heated by applying a voltage across the first and second electrodes. The voltage may be controlled in response to a measured temperature of the metallic GC column.

A GC interface assembly for a heated transfer line of a gas chromatography interface probe, the heated transfer line comprising an inner tube and an outer tube, the GC interface assembly comprising: a GC fitting securable to said inner tube, the GC fitting comprising a first section comprising a substantially cylindrical projection for fluid connection to a GC source in use, and a second section having a larger radius than the first section in at least one direction, the second section being provided with at least one flat; and a GC end cap securable to an outer tube, the GC end cap comprising an aperture which slidably receives the second section of the GC fitting in use such that the GC fitting is substantially constrained to liner movement with respect to the GC end cap.

A gas chromatography (GC) column system includes an insulation tubing, a metallic GC column disposed within the insulation tubing and having an outer diameter that is less than or equal to an inner diameter of the insulation tubing, a first electrode in contact with the metallic GC column, and a second electrode in contact with the metallic GC column on an opposite side of the insulation tubing from the first electrode. The metallic GC column may be heated by applying a voltage across the first and second electrodes. The voltage may be controlled in response to a measured temperature of the metallic GC column.

A GC fitting for an inner tube of a heated transfer line of a gas chromatography interface probe, the fitting comprising a first section comprising a substantially cylindrical projection for fluid connection to a GC source in use, and a second section having a larger radius than the first section in at least one direction, the second section being provided with at least one flat.

The disclosed system and method improve analysis of chemical samples for measurement of trace volatile chemicals, such as by Gas Chromatography (GC) and Gas Chromatography/Mass Spectrometry (GCMS). The system can include two traps in series, the first of which removes most of the unwanted water vapor, while the second trap preconcentrates the sample using a series of capillary columns of increasing adsorption strength. The sample can be backflushed from the second trap directly to a chemical analyzer without splitting which can maximize sensitivity. The system improves elimination of water vapor and fixed gases from the sample prior to analysis, resulting in detection limits as low as 0.001 PPBb. The second trap allows faster release of the sample upon injection to the chemical analyzer without additional focusing, and can be cleaned up faster when exposed to high concentration samples relative to packed traps.

A gas chromatography (GC) column system includes an insulation tubing, a metallic GC column disposed within the insulation tubing and having an outer diameter that is less than or equal to an inner diameter of the insulation tubing, a first electrode in contact with the metallic GC column, and a second electrode in contact with the metallic GC column on an opposite side of the insulation tubing from the first electrode. The metallic GC column may be heated by applying a voltage across the first and second electrodes. The voltage may be controlled in response to a measured temperature of the metallic GC column.