Chromatography sampling device and method

Abstract

The invention discloses a color spectrum sampling device which comprises an adsorption-thermal desorption module, a gas channel, filler, a temperature control module, an evacuation module and an analysis module, wherein the gas channel is arranged at the downstream part of the adsorption-thermal desorption module; the filler is arranged in the gas channel and used for adsorbing gas during refrigeration of the temperature control module and for thermally desorbing gas during heating of the temperature control module; the temperature control module is arranged on the gas channel and used for refrigerating and heating gas in the gas channel; the inlet end of the evacuation channel is connected with the outlet end of the gas channel; and the inlet end of the analysis channel is connected with the outlet end of the gas channel. The color spectrum sampling device disclosed by the invention has the advantages of narrow peak width, high detection sensitivity and the like.

Description

technical field [0001] The invention relates to the field of chromatographic analysis, in particular to a splitless chromatographic sampling device and method. Background technique [0002] figure 1 Schematically provides a simplified structure diagram of the chromatographic sampling device in the prior art, such as figure 1 As shown, the splitless splitless sampling connection method commonly used in the chromatographic sampling device can adopt two sampling modes: split and splitless. The main purpose of injecting samples at lower concentrations is to improve the sensitivity of the injection. [0003] However, the current conventional splitless splitless injection port has the following disadvantages when performing splitless sampling: [0004] 1) The main component of the sample is the solvent, so a large amount of solvent enters the chromatographic column during splitless injection, resulting in severe solvent peak broadening. For example, substances with boiling poin...

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Problems solved by technology

[0004] 1) The main component of the sample is the solvent, so a large amount of solvent enters the chromatographic column during splitless injection, resulting in severe solvent peak broadening. For example, substances with boiling points or properties close to the solvent are easily affected by the solvent peak, and it is difficult to use different solvents. Split injection mode for analysis

[0005] 2) Due to a large amount of solvent entering the chromatographic column, the chromatographic column is overloaded, especially when using a chromatographic column with an inner diameter of less than 0.25 mm, the phenomenon of chromatographic peak broadening and peak distortion caused by the overload of the chromatographic column is more serious, which may lead to a higher sensitivity than that under split conditions. bad situation

[0006] At present, the results of the conventional splitless inlet are still unsatisfactory for the separation of some substances. More expensive programmable temperature (PTV) inlets or cold column head direct column injection can be used.

[0007] However, the PTV injection port needs to be cooled with liquid nitrogen, and the large amount of liquid nitrogen needs to be replaced frequently. The use cost is high, and the liquid nitrogen tank is generally large in volume, which is cumbersome to operate and use, and there are certain risks. Requirements for operators higher

Moreover, the internal liner volume of the PTV inlet is relatively large, and the sample enters the chromatographic column slowly, which will cause peak broadening to a certain extent.

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