A gas chromatograph that includes a metering chamber, two separating devices and a multiport valve unit having switching functions for metering, straight separation, cutting and backflush, where the multiport valve unit is formed as a multiport diaphragm valve.

A gas chromatograph that includes a metering chamber, two separating devices and a multiport valve unit having switching functions for metering, straight separation, cutting and backflush, where the multiport valve unit is formed as a multiport diaphragm valve.

Disclosed is an organic carbon detector that can be used with a liquid chromatography equipment such as a size exclusion chromatography. The organic carbon detector contains a carbon oxidization subsystem and a stripping and CO.sub.2 detection subsystem arranged and detachably connected with each other in said order. The carbon oxidization subsystem contains a microfluidic agent injection module (1), an inorganic carbon removal module (2), a microfluidic ultraviolet oxidation module (3) and a vacuum pumping system (4), configured to remove inorganic carbons and oxidize organic carbons. The stripping and CO.sub.2 detection subsystem contains a stripping module (7) and a CO.sub.2 detector (12), using a carrier gas to transfer the organic carbon converted gas to the CO.sub.2 detector (12). Also disclosed is a method of using the organic carbon detector in water quality monitoring.

Disclosed is an organic carbon detector that can be used with a liquid chromatography equipment such as a size exclusion chromatography. The organic carbon detector contains a carbon oxidization subsystem and a stripping and CO.sub.2 detection subsystem arranged and detachably connected with each other in said order. The carbon oxidization subsystem contains a microfluidic agent injection module (1), an inorganic carbon removal module (2), a microfluidic ultraviolet oxidation module (3) and a vacuum pumping system (4), configured to remove inorganic carbons and oxidize organic carbons. The stripping and CO.sub.2 detection subsystem contains a stripping module (7) and a CO.sub.2 detector (12), using a carrier gas to transfer the organic carbon converted gas to the CO.sub.2 detector (12). Also disclosed is a method of using the organic carbon detector in water quality monitoring.

An improved gas chromatography system is presented. The system comprises: an enclosure having an inlet and an outlet, such that the ventilation flow is from the inlet to the outlet; a chamber disposed in the enclosure; a monolithic gas analyzer disposed in the chamber and a temperature control unit disposed in physical contact with the chamber. The monolithic gas analyzer operates to separate and detect molecules from a gas; whereas, the temperature control unit is configured to control temperature inside the chamber.

An improved gas chromatography system is presented. The system comprises: an enclosure having an inlet and an outlet, such that the ventilation flow is from the inlet to the outlet; a chamber disposed in the enclosure; a monolithic gas analyzer disposed in the chamber and a temperature control unit disposed in physical contact with the chamber. The monolithic gas analyzer operates to separate and detect molecules from a gas; whereas, the temperature control unit is configured to control temperature inside the chamber.

A gas analyzer system (100, 200, 300) and methods of reducing sample carryover in a gas sample selector (102, 202, 302). The gas analyzer system (100, 200, 300) includes a gas chromatograph (104, 204, 304) and a gas sample selector (102, 202, 302). The gas sample selector (102, 202, 302) includes a multi-position selector valve (130, 230, 330), a flush valve (140, 240, 340), and a purge valve (150, 250, 350), as well as conduits providing flowpaths between them. When switching the flush valve (140, 240, 340) to connect the flush valve (140, 240, 340) vent and flush valve (140, 240, 340) outlet and flowing purge gas through the purge valve (150, 250, 350) port, the purge gas will flow to the selector (102, 202, 302) exit and to the flush valve (140, 240, 340) vent to remove sample gas from the flowpaths.

A gas analyzer system (100, 200, 300) and methods of reducing sample carryover in a gas sample selector (102, 202, 302). The gas analyzer system (100, 200, 300) includes a gas chromatograph (104, 204, 304) and a gas sample selector (102, 202, 302). The gas sample selector (102, 202, 302) includes a multi-position selector valve (130, 230, 330), a flush valve (140, 240, 340), and a purge valve (150, 250, 350), as well as conduits providing flowpaths between them. When switching the flush valve (140, 240, 340) to connect the flush valve (140, 240, 340) vent and flush valve (140, 240, 340) outlet and flowing purge gas through the purge valve (150, 250, 350) port, the purge gas will flow to the selector (102, 202, 302) exit and to the flush valve (140, 240, 340) vent to remove sample gas from the flowpaths.

A gas component detection device includes a column, a sensor, a flow path, and a flow path switch. The column separates a component of gas to be detected. The sensor is, for example, a semiconductor sensor, is connected to the downstream side of the column, and detects a component of gas to be detected. The flow path connects the column and the sensor. The flow path switch is arranged between a flow path and a flow path. The flow path switch switches between and executes a measurement mode in which gas to be detected discharged from the column flows into the sensor, and a discharge mode in which gas to be detected discharged from the column is discharged to the outside.

A gas component detection device includes a column, a sensor, a flow path, and a flow path switch. The column separates a component of gas to be detected. The sensor is, for example, a semiconductor sensor, is connected to the downstream side of the column, and detects a component of gas to be detected. The flow path connects the column and the sensor. The flow path switch is arranged between a flow path and a flow path. The flow path switch switches between and executes a measurement mode in which gas to be detected discharged from the column flows into the sensor, and a discharge mode in which gas to be detected discharged from the column is discharged to the outside.