The Essence of the Principle Problem of Headspace Sampler

The headspace sampler is to put the sample to be tested into a closed container, volatilize the volatile components from the sample matrix by heating and heating, reach equilibrium in the gas-liquid (or gas-solid) two-phase, and directly extract the top gas for chromatographic analysis, so as to check the composition and content of the volatile components in the sample. The use of headspace sampling technology can eliminate the lengthy and cumbersome sample pretreatment process, avoid the interference of organic solvents on the analysis, reduce the pollution of the column and inlet. The instrument can be connected with various types of gas chromatograph at home and abroad.

Knowledge of gas chromatograph external gas path

Some gas chromatographs come with pressure reducing valves, if you don't need to buy them. The dioxygen-hydrogen pressure reducing valve is respectively installed on nitrogen, air and hydrogen cylinders (note that the thread of the hydrogen pressure reducing valve is reversed and the attached O-type plastic gasket is added to the interface for sealing). After tightening the nut, close the adjusting handle of the gas chromatograph pressure reducing valve (I. e. unscrew) and open the high pressure valve of the steel cylinder. At this time, the pressure gauge of the pressure reducing valve should have instructions. After the high-pressure valve is closed, the indicating pressure should not drop, otherwise there should be leakage, which should be eliminated in time (sealed with gasket or raw material tape). Sometimes the high pressure valve will leak, pay attention. Then turn the gas chromatograph adjustment handle to discharge the remaining gas

How to quickly and accurately determine the fault of the automatic headspace sampler?

The automatic headspace sampler is a convenient and quick sample pretreatment method in gas chromatography. Its principle is to place the sample to be tested in a closed container, and then heat up to make the volatile components volatilize from the sample matrix. After the gas-liquid (or gas-solid) two phases reach equilibrium, the top gas is directly extracted for chromatographic analysis to check the composition and content of volatile components in the sample. Headspace sampling technology can avoid lengthy and cumbersome sample pretreatment process, avoid the interference of organic solvents on the analysis, reduce the pollution of chromatographic columns and injection ports, and the instrument can be connected with various gas chromatographs at home and abroad.

Cleaning and maintenance of four main aspects of gas chromatograph

After the gas chromatograph is stopped, open the side panel and back panel of the instrument, and purge the dust of the instrument with instrument air or nitrogen, otherwise it will cause more dust or difficult to remove. Use a soft bristle brush to treat the place, and after cleaning, scrub the place where the instrument is contaminated with water or solvent. For water-soluble substances, you can wipe with water first, and the places that cannot be cleaned can be treated with solvents. For materials that are insoluble in water or may react with water, use solvents that do not react with them to clean the reacted materials.

Gas Chromatograph Promotes Laboratory Applications

The gas chromatograph is equipped with two detectors: thermal conductivity, hydrogen flame and reformer. Seven gases can be analyzed in one injection. The thermal conductivity adopts high resistance rhenium tungsten wire and built-in amplifier circuit, which greatly improves the detection sensitivity of hydrogen. With automatic ignition and cut-off gas protection function.

How to clean and maintain the gas chromatograph?

气相色谱仪停机后，打开仪器侧板和后面板，使用仪器 空气或氮气。 吹扫乐器上的灰尘，灰尘多或不易吹的地方用软毛刷应对。 清洗完成后，擦洗仪器被水或溶剂污染的地方。 对于水溶性物质，可以先用水擦拭，不能清洗的地方可以用溶剂处理。 对于不溶于水或可能与水发生化学反应的材料，用不与其发生反应的溶剂清洁反应过的材料。