Chromatographic filter paper can be divided into three types: fast, medium and slow. It is based on its different texture, the thickness and the speed of solvent unfolding on the filter paper.
When selecting the filter paper, people should combine the Rf value of the separated object. For the compounds with slight differences in Rf values, slow filter paper can be used to separate the compounds clearly because using the fast filter paper will cause the inseparable weight of the separation zone. For the compounds with large differences in Rf value, medium or fast filter paper is suitable.
As to the thickness of filter paper, it should be determined according to the purpose of separation analysis. The thin chromatography filter paper is used for general qualitative analysis, and the thick chromatography filter paper is used for quantitative analysis or preparation.
When the chromatographic filter paper is applied to the experiments, it should be treated by different methods, such as immersed in a non-polar solvent, insoluble inorganic, or salt solution or non-volatile solvent and so on. In a way like this, the filter paper can be buffered separately for reverse phase chromatography and separation.