Gas chromatographic column large-volume injection technology and application thereof

A technology of large-volume sampling and capillary chromatographic column, which is applied in the field of large-volume sampling on gas chromatography columns, can solve the problems of too fast disappearance of solvent liquid film, inconvenient operation of flame method, and inability to use flame method, etc., so as to avoid solvent Disappears too quickly, is easy to grasp and control, and is conducive to the effect of volatile analysis

Active Publication Date: 2018-02-02
SHANGHAI TOBACCO GRP CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the existing large-volume sampling technology on the gas chromatography column uses a constant pressure carrier gas for solvent evaporation, which has the following problems: in the process of sample injection and solvent evaporation, the solvent vapor resistance causes the carrier gas flow rate to drop greatly, and the evaporation rate When the solvent evaporates, the resistance of the pre-column decreases rapidly, and the flow rate of the carrier gas suddenly increases, which will easily lead to the disappearance of the solvent film too quickly, resulting in a serious loss of volatiles
The flame method is inconvenient to operate and has certain risks
In addition, solvents such as dichloromethane do not burn, so the flame method cannot be used

Method used

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  • Gas chromatographic column large-volume injection technology and application thereof
  • Gas chromatographic column large-volume injection technology and application thereof
  • Gas chromatographic column large-volume injection technology and application thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0138] Example 1 Large-volume sampling gas chromatography / mass spectrometry analysis of liquor flavor components

[0139] 1. Sample pretreatment

[0140] Take 0.5mL of a domestic liquor sample of a certain brand, add 1mL of water to dissolve, and then use 20mL of dichloromethane to shake and extract flavor components at room temperature.

[0141] 2. Large volume injection

[0142] Such as figure 1 As shown, according to the large-volume sampling system on the gas chromatography column of the present invention, a large-volume sampling-gas chromatography / mass spectrometry instrument on the column is built. Wherein, the sampling device adopts a fixed-speed syringe pump. The pre-column is a deactivated elastic quartz capillary with a size of 7m×0.53mm i.d. The capillary column is a polyethylene glycol capillary column with a specification of 30m×0.25mm i.d.×0.25μm df. The carrier gas is high-purity helium with a purity ≥99.99%.

[0143] 3. Instrument analysis conditions

[...

Embodiment 2

[0150] Example 2 Gel Permeation Chromatography-Gas Chromatography / Mass Spectrometry (GPC-GC / MS) Analysis of Tobacco Flavor Components

[0151] 1. Sample pretreatment

[0152] Take 0.2g of tobacco (cured tobacco leaf) powder, add 5mL of n-hexane: tert-butyl methyl ether (1:1, v / v) mixed solvent, let it stand overnight, after centrifugation, take the supernatant, transfer it to a 2mL chromatographic bottle, and pass through the automatic The injector injects the sample directly.

[0153] 2. Large volume injection

[0154] Due to the complex composition of tobacco extract, especially high-boiling components such as a large amount of oil and pigment, if it is directly injected into the gas chromatography pre-column, it is easy to cause serious pollution to the gas chromatography column system. Therefore, GPC was used to remove high-boiling point pollutants, and only the lower molecular weight aroma components were transferred to GC / MS. Due to the large volume of GPC fractions, ...

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Abstract

The invention belongs to the technical field of gas chromatography and relates to a gas chromatographic column large-volume injection technology and application thereof. The invention provides a gas chromatographic column large-volume injection system, which comprises a carrier gas injection part and a chromatographic injection part. The chromatographic injection part comprises an injection port,a pre-column, a drain valve, a capillary chromatographic column and a chromatographic column box. The carrier gas injection part comprises a constant-current mode carrier gas access and a constant-voltage mode carrier gas access. The invention also further provides application of the gas chromatographic column large-volume injection device and an injection method. The invention provides a gas chromatographic column large-volume injection technology and application thereof. According to the invention, pure pressure control mode is changed into constant current-constant voltage switching mode. Thus, solvent evaporation is faster and more stable, and solvent evaporation end point is easier to control, thus being beneficial to performance of solvent effect and analysis of volatile matter. Thetechnology is widely applied.

Description

technical field [0001] The invention belongs to the technical field of gas chromatographic analysis, and relates to a large-volume sampling technology on a gas chromatographic column and its application. Background technique [0002] The conventional injection volume of capillary gas chromatography is generally 1-2μL, and the large-volume injection generally refers to 20-1000μL. In large-volume gas chromatography injection, solvent evaporation techniques are key. According to solvent evaporation technology, gas chromatography large-volume sampling technology is generally divided into three categories, namely, programmed temperature vaporization (PTV), quantitative loop interface (Loop-type interface) and on-column sampling interface (On-column interface). Among the above three techniques, on-column sampling can make full use of the solvent effect, and the loss of volatiles is low. It is suitable for the analysis of volatile components and has high application value in the f...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G01N30/16
CPCG01N30/16
Inventor 刘百战谢雯燕毕艳玖王亮
Owner SHANGHAI TOBACCO GRP CO LTD
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