Flash chromatography is a kind of fast chromatographic separation mode, which separates substances by using optimized pre-packaged medium and low-pressure columns.
Flash chromatography, which was developed in 1978, is considered to separate by medium and low pressure. And it is a fast and inexpensive technology compared with traditional chromatography, which is widely used in drug research, sample purification, and purification of natural products currently. The characteristics of low-cost and simplicity result in its irreplaceable in the separation and purification.
The most used common filler for flash columns is silica gel. But why silica gel is chosen to be the filler?
One of the reasons is the limited choice of fillers using for the chromatographic columns at that time. And another reason is other bonds, such as C8 and C18, are too expensive.
As a consequence, most methods of flash chromatographic application in the literature are developed using silica gel as the separation substrate. Flash chromatography usually is a normal-phase liquid chromatography technology.
The size of the sample is usually in the milligram level to a hundred-gram. The flow rate is 10 mL/min to 300 mL/min. And organic solvents with low polarities, such as hexane and ethyl acetate, are used as the mobile phases.