Thin layer chromatography (TLC) is to coat a suitable stationary phase on a glass plate, plastic or aluminum substrate to form a uniform thin layer. After sampling, the specific shift value (Rf) is compared with the specific shift value (Rf) of the chromatogram obtained by the same method for drug identification, impurity inspection or content determination. Thin layer chromatography is an important experimental technique for rapid separation and qualitative analysis of small amounts of substances, and it is also used to track the reaction process.

Basic principle of thin-layer chromatography: Thin-layer chromatography is an adsorption thin-layer chromatography separation method, which uses the different adsorption capacities of components to the same adsorbent, so that the mobile phase (solvent) continuously produces adsorption, desorption, re-adsorption and re-adsorption during the process of flowing through the stationary phase (adsorbent), thus achieving the purpose of separating components from each other.

Extended data:

The reason why matter molecules can stay on the solid surface is because the attraction between the molecules (ions or atoms) on the solid surface and the molecules inside the solid is not equal. Inside a solid, the forces that interact between molecules are symmetrical, and their force fields cancel each other out. However, the force on the solid surface molecules is asymmetric, and the force on the inner surface of the solid is less, so the gas or solute molecules will be attracted and stay when they meet the solid surface in motion. The adsorption process is reversible, and the adsorbed substances can be desorbed under certain conditions.

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