| Physical and Chemical Properties | Silica gel column chromatography is divided into normal phase silica gel column chromatography and reverse phase silica gel column chromatography. The normal phase silica gel column chromatography is suitable for the separation of relatively small polar compounds, such as various types of aglycones; therefore, organic solvents with low polarity are usually used as eluents, such as petroleum ether-dichloromethane elution system, chloroform-ethyl acetate elution system, etc. |