ELECTRO-DRIVEN SAMPLING EQUIPMENT FOR GAS CHROMATOGRAPH Russian patent published in 2018 - IPC G01N33/12 

FIELD: instrument engineering.

SUBSTANCE: invention relates to analytical instrument engineering, in particular to sampling devices in chromatograph, namely to technique of microdose samples. Sampling equipment includes feed line of carrier gas, feed line of test gas, delivery line of carrier gas to a chromatographic tube, vent line of test gas, outside loop of sampling. Three electromagnetic two-position triple-ported valves with a short switching time (less than 3 ms) are used to switch lines. Input port of the first valve is connected to feed line of carrier gas, and its two outputs are connected – one with the feed line of carrier gas to the tube and the second one – with the inlet line of sampling loop. Input port of the second valve is connected to feed line of test gas, with one outlet port of this valve is connected to the inlet line of sampling loop, and the second outlet port – to vent line of test gas. Input port of the third valve is connected to outlet line of sampling loop, one outlet port of this valve is connected to vent line of test gas, and the second outlet port is connected to the feed line of carrier gas in the tube. Connective hydraulic lines between the valves are made in monolithic base and have internal volume less than 0.05 ml.

EFFECT: elimination of the flow of carrier gas into sampling line, reducing erosion of chromatographic peaks, as well as improving accuracy and reliability of the device.

3 cl, 2 dwg