Method for emptying solvent from liquid chromatography and gas chromatography on-line coupling interface

Abstract

A gas chromatography / mass spectrometry (GC / MS) large-volume sample introduction system and an analysis method thereof. A solvent emptying device is connected between a reserving pre-column (4) of a gas chromatograph and a gas chromatographic separation column (10). The solvent emptying device comprises two three-way connectors (5, 8) and a two-direction changeover valve (7) connected between the two three-way connectors (5, 8). The device system is used for analysis, the volume of a sample introduction liquid is not limited, the reserving pre-column (4) and the gas chromatographic separation column (10) are automatically connected or isolated through the two-direction changeover valve (7), and almost no solvent enters the gas chromatographic separation column (10) and a detector (11). The three-way connectors (5, 8) are adopted to facilitate connection of a capillary chromatographic column and the changeover valve (7), and flow division of a flow limiting tube eliminates the occurrence of a dead volume. The device system and the analysis method thereof are applicable to GC / MS large-volume sample introduction and ordinary GC large-volume sample introduction, also applicable to a liquid chromatography-GC online combined system, and especially applicable to liquid chromatography-GC / MS online combined analysis.

Description

technical field [0001] The invention relates to a solvent evacuation method for an online liquid chromatography-gas chromatography interface, and belongs to the technical field of chromatography detection. Background technique [0002] Liquid chromatography-gas chromatography technology is a new multi-dimensional chromatography technology, which has both the high selectivity of liquid chromatography (LG) and the high efficiency and high sensitivity of gas chromatography (GC). It has strong processing, enrichment, separation and detection capabilities, and is of great significance to the analysis of complex organic mixtures such as environmental monitoring, pesticide testing, food testing, natural products, petrochemical and biomedicine, and samples with complex backgrounds. . [0003] In the study of complex systems, LC is often used to pre-separate the mixture into multiple fractions. For the target fractions of interest, GC / MS or selective detectors are used for further a...

AI Technical Summary

Problems solved by technology

The commonly used method of solvent evacuation is to discharge the solvent into the atmosphere through the tee joint, but this technology still has a small amount of solvent entering the analytical column and detector, especially for the mass spectrometer, because of its vacuum effect, there will be a large amount of solvent It is sucked into the analytical column and mass spectrometer system, thereby contaminating the ion source and causing the vacuum degree of the mass spectrometer to drop. In severe cases, it will cause the mass spectrometer to alarm or even shut down

Therefore, how to completely remove the solvent and introduce the components to be measured into the GC, there is no perfect solvent evacuation technology at present

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