Gas chromatograph for analyzing trace impurities in electronic grade hexafluoroethane

Abstract

The invention relates to a gas chromatograph for analyzing trace impurities in electronic grade hexafluoroethane. The structure of the gas chromatograph comprises a sample feed system, a transfer valve, a chromatographic column, a discharge needle valve and a detector. The gas chromatograph is characterized in that the sample feed system comprises a sample inlet, a sample outlet, a first quantitative pipe, a second quantitative pipe and a third quantitative pipe; the transfer valve comprises a first transfer valve, a second transfer valve, a third transfer valve, a fourth transfer valve and a fifth transfer valve; the chromatographic column comprises a first chromatographic column, a second chromatographic column, a third chromatographic column, a fourth chromatographic column, a fifth chromatographic column and a sixth chromatographic column; the discharge needle valve comprises a first needle valve, a second needle valve, a third needle valve, a fourth needle valve, a fifth needle valve and a sixth needle valve; the detector comprises a helium ionized first detector PDD1 and a second detector PDD2. According to the invention, samples are fed once, the chromatographic analysis for each inorganic impurity in the electronic grade hexafluoroethane is completed, the sensitivity is high, the repeatability is good, and the chromatographic analysis conforms to the standard.

Description

technical field [0001] The present invention relates to a gas chromatograph, and in particular discloses a detection device for the analysis of trace impurities in electronic-grade hexafluoroethane, which utilizes the high sensitivity of a PDD detector to detect ppb-level impurities in hexafluoroethane, especially to solve It overcomes the difficulties in the analysis of trifluorochloromethane (R13) in hexafluoroethane, and realizes the full analysis of trace impurities in electronic grade hexafluoroethane. Background technique [0002] Hexafluoroethane, also known as perfluoroethane, is the product of all six hydrogen atoms in ethane being replaced by fluorine atoms, also known as fluorocarbon 116 (R116). Hexafluoroethane is a colorless, odorless, tasteless, non-flammable, non-toxic gas, basically insoluble in water, slightly soluble in alcohol, and its physical and chemical properties are stable. [0003] Hexafluoroethane is mainly used in low-temperature refrigeration, e...

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Problems solved by technology

[0004] The purpose of the present invention is to solve the problems in the prior art, to design a gas chromatograph for the analysis of trace impurities in electronic grade hexafluoroethane, and to solve the analytical difficulties of R13 in hexafluoroethane by using the heart cutting method, Achieving one injection operation can complete the inorganic impurities (H) in hexafluoroethane 2 , O 2 +Ar,N 2 , CO 2 , CO) and halogenated hydrocarbon impurities (R14, R13, R115, R23, R143a, R113, etc.) chromatographic analysis of impurities, and the high-sensitivity detection limit of the helium ionization detector reaches the ppb level

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