A gas chromatograph is provided which is capable of effectively reducing the amount consumed of a carrier gas, reducing the time and effort required for an operator to manually set parameters, and preventing damages to a column and a detector due to a setting mistake. In a case where a stop operation for the power supply of the gas chromatograph is performed (Yes in step S101), the flow rate of a carrier gas to be supplied to a sample vaporization chamber is decreased and the temperatures of the column and the detector are sufficiently lowered (steps S102 to S104), and then the power supply of the gas chromatograph is switched over from an ON state to an OFF state (step S106).

Samples are analyzed in a system that includes a gas chromatography column for separating components in a sample and a spectrometry system for detecting these components. An interferent present in the sample, water for example, flows through the column and the sample cell of the spectrometry system before beginning the analysis of analytes.

A carrier gas flow path of at least from a trap to an analyzing portion is shared between a state wherein a sample component is trapped within the trap and a state wherein the sample component is not trapped within the trap. In this case, even after the sample has been introduced into the analyzing portion through the carrier gas flow path, there is a time interval over which the carrier gas flows within the carrier gas flow path. This makes it possible, through the carrier gas that flows within the carrier gas flow path afterward, to remove the sample component from within the flow path, despite there being a sample component within the carrier gas flow path at the time of sample introduction, thus making it possible to prevent the sample component from remaining within the flow path after sample introduction.

The present disclosure is directed to methods and systems for detecting a chemical substance. The methods and systems include using gas-solid phase chemistry to chemically and/or physically modify a substance of interest so that the substance can be vaporized and detected through an analysis of the substance.

The present disclosure is directed to methods and systems for detecting a chemical substance. The methods and systems include using gas-solid phase chemistry to chemically and/or physically modify a substance of interest so that the substance can be vaporized and detected through an analysis of the substance.

A multi-capillary column pre-concentration trap for use in various chromatography techniques (e.g., gas chromatography (GC) or gas chromatography-mass spectrometry (GCMS)) is disclosed. In some examples, the trap can include a plurality of capillary columns connected in series in order of increasing strength (i.e., increasing chemical affinity for one or more sample compounds). A sample can enter the trap, flowing from a sample vial to a relatively weak column to the relatively strongest column of the trap by way of any additional columns included in the trap, for example. In some examples, the trap can be heated and backflushed so that the sample exits the trap through the head of the relatively weak column. Next, the sample can be injected into a chemical analysis device for performing the chromatography technique (e.g., GC or GCMS) or it can be injected into a secondary multi-capillary column trap for further concentration.

Techniques disclosed herein can improve the extraction of chemicals prior to analysis by GC or GCMS. A liquid or solid sample can be placed in a sample container of a closed system under vacuum that further includes a sample extraction device. The assembly can be placed in a 3-zone heater that can separately control the temperature of the bottom of the sample container, the top of the sample container, and the sample extraction device. Vapor flux from the bottom of the sample container into the headspace of the sample container can deliver compounds of interest to the sample extraction device, whereas matrix compounds can re-condense in the headspace of the sample container to avoid delivery to the sample extraction device. Extraction can continue until substantial transfer of compounds of interest to the sorbent occurs, followed by thermal desorption of the extract into a GCMS for analysis.

Techniques disclosed herein can improve the extraction of chemicals prior to analysis by GC or GCMS. A liquid or solid sample can be placed in a sample container of a closed system under vacuum that further includes a sample extraction device. The assembly can be placed in a 3-zone heater that can separately control the temperature of the bottom of the sample container, the top of the sample container, and the sample extraction device. Vapor flux from the bottom of the sample container into the headspace of the sample container can deliver compounds of interest to the sample extraction device, whereas matrix compounds can re-condense in the headspace of the sample container to avoid delivery to the sample extraction device. Extraction can continue until substantial transfer of compounds of interest to the sorbent occurs, followed by thermal desorption of the extract into a GCMS for analysis.

A system for analyzing a gas mixture is provided. The system includes an enclosure inlet. A moisture trap assembly is coupled to the enclosure inlet. The moisture trap assembly removes excess moisture from a sample at the enclosure inlet. A testing section is coupled to the moisture trap assembly for detecting one or more compounds from the sample.

An upstream portion of a flow path is stored in a cell block. A filament for detecting thermal conductivity of a sample gas is stored in the upstream portion. The sample gas is led to a downstream portion of an exhaust pipe path through the flow path. The flow path is kept warm by a temperature retainer such that the temperature of the sample gas that passes through the exhaust pipe path does not decrease to a temperature equal to or lower than a liquefaction temperature of the sample gas. Alternatively, at least one portion including a downstream end of the exhaust pipe path is provided to be attachable to and detachable from another portion of the flow path.