Comprehensive two-dimensional gas chromatograph and optimization modulation method thereof

Abstract

The invention discloses a gas flow modulation device for a comprehensive two-dimensional gas chromatograph. The gas flow modulation device comprises a gas supplementation module, a switch valve, a first vapor lock and a second vapor lock, wherein a gas outlet of the gas supplementation module is connected to an intake of the switch valve through a pipeline; a first outlet of the switch valve is used for connecting an inlet of a modulator through a pipeline; a second outlet of the switch valve is connected with a first end of the second vapor lockthrough a pipeline; a second send of a second vapor lockis connected with an outlet of the modulator through a pipeline; a first end of the first vapor lockis connected with the inlet of the modulator through a pipeline; a second end of the first vapor lockis connected with the outlet of the modulator through a pipeline. Through the gas flow modulation device, the defects that a modulated two-dimensional initial peak width and a compound boiling spread, which can be modulated, are mutually contradictory and cannot be taken into consideration at the same time are overcome and not only is a wider compound boiling spread, which can be modulated, obtained but also a narrower two-dimensional initial peak width is obtained.

Description

Technical field [0001] The invention relates to the technical field of analytical instruments, in particular to a key device and method for optimizing the performance of a comprehensive two-dimensional gas chromatograph. Background technique [0002] Comprehensive Two-dimensional Gas Chromatography (GC×GC) is a new chromatographic analysis technology developed on the basis of traditional one-dimensional gas chromatography in the 1990s. The main principle is to connect two independent chromatographic columns with different separation mechanisms in series. A modulator is installed in the middle. All distillates separated by the first column are concentrated and collected in the modulator. The periodic pulse form is released into the second column for continued separation, and finally enters the chromatographic detector. In this way, the components (co-distillate) that are not completely separated in the first dimension are further separated in the second dimension, achieving the e...

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Problems solved by technology

When the wide-mouth column is prepared, the flow rate of the airflow in the column is relatively slow, and the analyte components with lower boiling points at the same low temperature are relatively easy to be condensed, adsorbed or trapped, and the compounds that can be prepared have a wide range of boiling points, which is better. ; However, due to the slow flow rate of the gas flow in the column, the trapped components at the same high temperature are released slowly, resulting in a wider two-dimensional initial peak width after modulation, and this performance is poor

Narrow-mouth column modulation is just the opposite of wide-mouth column modulation. The gas flow in the column is faster, and the boiling point range of the compound that can be modulated is narrower. However, the two-dimensional initial peak width after modulation is narrower.

Regardless of which of the above configurations is chosen, two important properties cannot be balanced

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