Flash column chromatography can overcome the defect of ordinary column’s separation. It has the advantages of quick, time saving, high efficiency of separation, simple and practicable. As for samples of 0.01 to 10 grams and the Rf value of more than 0.15, they can be quickly separated within 10 to 15 minutes.
1. The adsorbed stationary phases are normally silica gel and aluminum oxide. The required mesh numbers are 100 to 160 or above 160, 2. The lower of adsorbing agent’s mesh number is, the higher degree of separation will be. However, the elution rate will be relatively slower, 3. When there are great differences between the Rf values, you can load 30 mg/g of silica gel with a mesh number of 100 to 160. In more cases, 10 mg/g of silica gel is required, 4. When using aluminum oxide, the required mesh number is 100 to 150. 20 to 50 grams of aluminum oxide are needed to separate 1 gram of sample.
1. Choose the eluting agent with high separation efficiency on TLC board, 2. Choose an appropriate chromatographic column with silica gel with a mesh number of 230 to 400, 3. After the eluting agent is added, quickly eliminate the air inside the silica gel under the pressure, 4. After sample loading, elute, and control the flow rate within 2.0 in/min.