What can a gas chromatograph do, and what does a gas chromatograph mainly measure

Gas chromatography is the detection and analysis of gaseous substances or substances that can be converted into gases at a certain temperature. Due to the different physical properties of the substance, the distribution coefficient of each component in the sample is different between the gas phase and the fixed liquid phase, when the vaporized sample is brought into the chromatographic column by the carrier gas to run, the components are repeatedly distributed between the two phases, due to the different adsorption or solubility capacity of the fixed relative components, although the carrier gas flow velocity is the same, the running speed of each component in the column is different, after a certain period of flow, they are separated from each other, leave the column in order to enter the detector, and the signal generated is amplified. The chromatographic peaks of each component are depicted on the logger. Depending on the location of the peak, the name of the component is determined, and the size of the concentration is determined according to the peak area.

Gas chromatograph: a medical device.

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Gas chromatographs are mainly used to detect volatile organic substances, and the application range is as follows:

1. Environmental protection: analysis, monitoring and research of trace poisons in polluted places such as atmospheric water sources.

2. Biochemistry: clinical application, pathology and toxicology research.

3. Food fermentation: analysis and research of trace components in microbial beverages.

4. Chinese and Western medicines: analysis of raw material intermediates and finished products.

5. Petroleum processing: petrochemical industry, petroleum geology, oil composition and other analysis and control and mineral control research.

6. Organic chemistry: component research and production control in the field of organic synthesis.

7. Health inspection: analysis and research of labor protection and pollution detection.

8. Cutting-edge science: military detection, control and research.

Petrochemical analysis, environmental analysis, food analysis, pharmaceutical analysis, physical and chemical research, polymer analysis. Gas chromatography refers to chromatography that uses gas as the mobile phase. Due to the rapid transfer of the sample in the gas phase, the sample components can be instantaneously equilibrated between the mobile and stationary phases.

In addition, there are many substances that can be used as stationary phases, so gas chromatography is a fast and efficient separation analysis method. <

In petrochemical analysis, in environmental analysis, in food analysis, in pharmaceutical analysis, in physicochemical research, polymer analysis. Gas chromatography refers to chromatography that uses gas as the mobile phase. Due to the rapid transfer of the sample in the gas phase, the sample components can be instantaneously equilibrated between the mobile and stationary phases.

In addition, there are many substances that can be used as stationary phases, so gas chromatography is a fast and efficient separation analysis method. In recent years, high-sensitivity selective detectors have been adopted, which makes it have the advantages of high analytical sensitivity and wide range of applications.

In fact, gas chromatography (GC) is a separation technique. In practice, the samples to be analyzed are often multi-component mixtures in complex matrices, and samples containing unknown components must first be separated before the relevant components can be further analyzed. The separation of mixtures is based on the differences in the physical and chemical properties of the components, and the gas chromatograph mainly uses the differences in the boiling point, polarity and adsorption properties of substances to achieve the separation of mixtures.

After vaporization in the vaporization chamber, the sample to be analyzed is brought into the column by an inert gas (i.e., carrier gas, generally N2, HE, etc.), which contains a liquid or solid stationary phase, and each component tends to form a partition or adsorption equilibrium between the mobile phase and the stationary phase due to the different boiling points, polarity, or adsorption properties of each component in the sample. However, due to the flow of the carrier gas, this equilibrium is actually difficult to establish, and it is precisely because of the flow of the carrier gas that the sample components are repeatedly assigned or adsorbed and deattached in the movement, and as a result, the components with a large concentration in the carrier gas flow out of the column first, and the components with a large concentration in the stationary phase flow out after being distributed.

Gas chromatographs generally consist of a gas path.

The system, the injection system, the separation system (column system), the detection and temperature control system, and the recording system are composed.

A gas chromatograph is an instrument that uses chromatographic separation technology and detection technology to perform qualitative and quantitative analysis of complex mixtures of multiple components. Organic compounds that are thermally stable and have a boiling point of no more than 500 degrees Celsius can be analyzed, such as volatile organic compounds, can usually be analyzed.

The principle is to use gas as the mobile phase, due to the difference in the distribution of each component between the mobile phase (gas phase) and the stationary phase (liquid phase or solid phase) in the chromatographic column, under the action of the carrier gas, each component is repeatedly distributed between the two phases, so that the components are separated in the column, and then the detector connected to the back of the column is used to detect each component according to the physical and chemical properties of the components.

Gas chromatograph is an analytical instrument widely used in chemistry, environment, medicine and other fields. When using a gas chromatograph, the sample is first prepared and the compounds in the sample are separated by a specific method. These compounds are then injected into a gas chromatograph and allowed to separate them in the column.

Finally, the separated compounds were detected by a tumbling cavity detector, and the corresponding signal was generated. The following points need to be paid attention to when using the method of gas chromatograph:1

Sample preparation: Samples should be sufficiently volatilized or dissolved in an appropriate solvent. It is important to note that unnecessary contamination or compromise the operation of the instrument should be avoided when performing sample preparation.

2.Column selection: Choosing the appropriate column will ensure the best possible sample separation.

3.Mobile phase selection: Different compounds require different mobile phases, and choosing the appropriate mobile phase can improve the efficiency of sample separation.

4.Detector selection: Select the appropriate detector according to your needs.

5.Use of the instrument: When using the instrument, you should pay attention to the operation rules to avoid damage to the instrument.