First of all, flash chromatography is a rapid separation mode of chromatography preparation. It applies the optimized preloaded medium and low-pressure columns for chromatographic separation. Since the flash chromatography is considered as medium and low-pressure chromatographic separation, its sharpness of separation is relatively lower than the High-Performance Liquid Chromatography.
Now, the flash chromatography technology is widely applied in research and development of drugs, sample purification, natural product refinement, and other fields. On the whole, due to the advantages of low-cost, convenient, and fast, the flash chromatography becomes one of the indispensable chromatographic separation tools for current High-Performance Liquid Chromatography preparation.
Types of HAWACH Flash Column HAWACH flash columns fall into the following three series: StarFlash series: silica gel flash column only, this series can be divided into standard and advanced sub-categories. Advanced silica has higher purity and better quality. Other Flash series: silica gel construction and phase column. For example, C18(spherical inlet and irregular home-made), C4, C8, NH2, CN, HILIC, and oxide which are all imported fillers, corresponding to the high-end market. DepuFlash series: silicone construction and phase columns, C18 (spherical and irregular),C8, NH2, CN, Phenyl, SAX, SCX, Diol are domestic fillers, corresponding to the low-end market.
In terms of the regular fillers of flash columns, the most frequently used filler is silica gel. Because in the early stages, the choice of filler for flash columns and thin-layer chromatography is limited. Also, some other bonded phases, such as C8 and C18 are too expensive. As a result, most of the application methods for flash columns are using silica gel as the separation matrix.
Flash column refers to saturated water with high pressure entering a relatively low-pressure container, and the saturated water becomes a part of the saturated water vapor and saturated water under the pressure of the container due to the sudden decrease in pressure. In the chemical production process, the flash column can realize rough gas-liquid phase separation of materials. Before entering the atmospheric furnace, the flash column can be roughly separated, which can reduce the load of the atmospheric furnace.
How does the flash column work? When water is heated at atmospheric pressure, 100 ° C is the highest temperature allowed for liquid water at that pressure. Reheating does not increase the temperature of the water, but only converts it into steam. The heat absorbed by water before it reaches the boiling point is called “sensible heat,” or saturated water sensible heat. “latent heat” is The heat required to convert saturated water into steam at the same atmospheric pressure.
However, if the water is heated under a certain pressure, the boiling point of water will be higher than 100 ° C, so more sensible heat is required. With the higher the pressure, the higher the boiling point of water and the higher the heat content. The pressure decreases and part of the sensible heat are released. This part of the excess heat will be absorbed in the form of latent heat, causing some water to be “flashed” into steam.