To Have A Full Knowledge Of Flash Column-Definition, Development And Advantages
In the narrow sense, FLASH refers to the preparation of a liquid chromatography system using a low-pressure short column that generates pressure with compressed gas and accelerates the elution rate of the mobile phase. In the broad sense, FLASH refers to all low-pressure liquid chromatography systems for infusion.
Development of flash column
After more than 20 years of development, FLASH chromatography has been widely used as a conventional purification and separation equipment. FLASH chromatography was born out of open glass column chromatography and is mainly used for the separation and purification of natural products and organic synthetic products.
Classical FLASH chromatography consists of a glass column, a liquid storage bottle, and a compressed air regulating valve. This type is low cost and easy to observe, but has low pressure and is easy to break. After improvement, a classic FLASH chromatography system was formed. It consists of an infusion pressure tank, a flow regulating valve, a flash preloading column, and a sample loading device. The equipment is compact, high pressure, easy to use, and highly reproducible. Classic FLASH chromatography still uses air pressure, with a pressure range of about 0-7 bar, a column length of about 15 cm, and a particle size of 40-60. Load solids and liquids and collect fractions manually.
Recently, due to the intensification of scientific research competition and the increase of labor costs in laboratories, a higher degree of automation and separation speed is required, and automated FLASH chromatography has been generated. The instrument also has a gradient elution system, a column switching system, and an automatic sampling system. The conditions can be selected and optimized to achieve unmanned operation, which greatly reduces labor costs and speeds up development.
Advantages of flash column
FLASH chromatography is used for preparation and has the following advantages:
1. Fast speed, generally 1/8 of the separation time of open column chromatography, saving time, slow sample change and decomposition
2. Large preparation volume, at least as compared with an HPLC preparation column of the same diameter. Double the amount of sample.
3. Low cost. First, the equipment is lower than HPLC. Second, the use of solvents saves more than glass columns. Silica gel columns can be used multiple times to save the amount of silica gel.
Easy to use, no special solvent treatment is required, samples can be loaded dry, and personnel does not need special training.
The effect of FLASH chromatography mainly depends on the optimization of the elution solvent and the packing effect of the column. When dealing with the relationship with preparative HPLC, the following principles should be followed: (1) When only FLASH chromatography can be used, preparative HPLC is not required; (2) First use flash chromatography, then use purification and preparative HPLC. Other usage techniques are: Use TLC to select anti-solvent and loading capacity; Use short thick column (diameter: length <= 1: 7).
HAWACH has three series of flash columns and they use the medical PP column, medical sintered PE sieve plate, and high-quality adsorbent packing.
StarFlash series: only silica gel columns, standard and advanced types whose silica gel with higher purity and better quality.
PureFlash series: silica gel phase column, C18 (spherical inlet and irregular domestic), C4, C8, NH2, CN, HILIC, aluminum oxide, etc.
DepuFlash series: silica gel phase column, C18 (spherical and irregular), C8, NH2, CN, Phenyl, SAX, SCX, Diol.