Supercritical selective dehydration extraction-variable pressure focusing supercritical fluid chromatography online analysis system and analysis method

Abstract

The invention relates to a supercritical selective dehydration extraction-variable pressure focusing supercritical fluid chromatography online analysis system comprising a carbon dioxide pump, a firstchromatographic pump, a second chromatographic pump, a first six-way switching valve switching flow paths, a second six-way switching valve for switching flow paths, a mixer, a supercritical fluid extraction device adopting a selective adsorbent, a chromatographic column, an ultraviolet detector, a mass spectrum detector, a three-way connector A, a three-way connector B, a three-way connector C,a first back pressure regulator, a second back pressure regulator and a connecting pipe for connecting all parts. The invention also relates to an analysis method of the system. According to the invention, the problem of impurity interference in a sample matrix is solved, and the problem of chromatographic peak broadening caused by non-focusing of a large amount of extraction liquid at the columnhead of the chromatographic column when the existing supercritical fluid extraction-supercritical fluid chromatography combined system is used is also solved.

Description

technical field [0001] The invention belongs to the field of analytical chemical sample pretreatment, and specifically relates to a supercritical selective dehydration extraction-pressure variable focusing supercritical fluid chromatography online analysis system and analysis method Background technique [0002] Supercritical fluid chromatography (SFC) is a powerful tool in modern separation science. It has advantages that liquid and gas chromatography do not have, and SFC can also be used to analyze chiral or unstable compounds that are difficult to analyze in liquid or gas chromatography. Supercritical carbon dioxide is the most commonly used mobile phase in SFC because it has a moderate critical pressure and temperature (7.3MPa, 31°C), has good safety performance, is non-flammable, non-corrosive, and has low toxicity. In addition, carbon dioxide is cheap and Miscibility with most organic solvents offers a wide range of possibilities for optimizing chromatographic separat...

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Problems solved by technology

[0005] Based on this, the present invention provides a supercritical selective dehydration extraction-pressure swing focusing supercritical fluid chromatography on-line analysis system to solve the problem of impurity interference in the sample matrix, and at the same time solve the problem of existing supercritical fluid extraction-supercritical fluid chromatography When the system is used, the problem of chromatographic peak broadening caused by the unfocusing of a large amount of extract at the head of the chromatographic column improves the accuracy and precision of the analysis and expands the application range of the online supercritical fluid extraction-supercritical fluid chromatography technology

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