The scope and use of gas chromatograph

In principle, any substance that has a low molecular weight, has a certain volatility, does not decompose under vaporization or column temperature, or has a large molecular weight, but can be derived into volatile compounds through various treatments, and can also be analyzed by gas chromatography. Specific to the current commercial gas chromatographs, GC is generally suitable for analysis groups with a Buddha point below 350℃. High-temperature GC can analyze components. In principle, all molecular weights are not large and have certain volatility. In the case of substances that do not decompose, or have a large molecular weight, but can be derived into volatile compounds through various treatments, it can also be analyzed by gas chromatography. Specific to the current commercial gas chromatographs, GC is generally suitable for the analysis group with a Buddha point below 350°C, and high-temperature GC can analyze components with a Buddha point not exceeding 500°C. Among the instrumental analysis methods, the chromatographic analysis can perform separation and detection analysis at the same time. Compared with other instrumental analysis methods, it has unique advantages. Because of its high separation efficiency, it is almost an indispensable analysis method for sample analysis of multi-component complex mixtures, isomers, optical isomers, and trace components. At present, with the continuous development of detection technology, sample processing technology, and microelectronics technology, the detection limit of GC has been expanded from the initial 10-2 to 10-13 and even some analyses can reach the order of 10-15. However, it is found in the current commercial conventional detectors that are generally matched with gas chromatography. They cannot give characteristic signals according to the composition of the components to be analyzed. The qualitative analysis with conventional GC is still subject to certain restrictions. For such problems, it is necessary to use a variety of instruments Confirmed by joint use and cooperation. The instrumental analysis methods currently used for online coupling mainly include: GC/MS, GC/FIR, LC/MS, LC/NMR, etc.