Liquid chromatography is one of the most important methods for trace analysis of material components. The two phases in chromatographic analysis refer to a stationary phase with a large specific surface area and a mobile phase carrying the mixture to be separated through the stationary phase. Liquid chromatography is used for the mobile phase. Liquid chromatography is also called "liquid chromatography". A method for chromatographic analysis. The mobile phase used is liquid. Because the liquid in the chromatography column is more resistant than the gas, in order to improve the analysis speed, the high-pressure infusion method is usually used, so it is also called "high-pressure liquid chromatography". According to the different stationary phases, it can be divided into liquid-solid chromatography and liquid-liquid chromatography; according to the type of equilibrium that occurs between the stationary phase and the mobile phase, it can be divided into adsorption chromatography, partition chromatography, ion exchange chromatography, and gel chromatography. Used for separation and analysis of organic matter, inorganic matter and polymer liquid.