Hawach To Introduce The Flash Column Comprehensively
In 1978, Sill invented Flash chromatography, and the article was published in J.O.C. Since then, the Flash chromatography method has been established, and new equipment has been constantly emerging. The narrow sense of the Flash column refers to a low-pressure short column preparation liquid chromatography system that uses compressed air to generate pressure and accelerate the elution speed of the mobile phase. The generalized Flash column system refers to all low-pressure liquid chromatography systems for infusion methods.
Flash column is born out of open glass column chromatography and is mainly used for separation and purification of natural products and organic synthesis products. The classical Flash column consists of a glass column, a storage bottle, and a compressed air regulating valve. This type has low cost and is easy to observe, but has low pressure and easy to break.
Many laboratories now place a pressurized ball on the top of a glass column, which is a similar product. After improvement, a classic Flash column system was formed, which is composed of an infusion pressure tank, flow regulating valve, Flash pre-packed column, and sample loading device. The classical Flash column still uses air pressure with a 0-7bar pressure range. The column length is about 15cm, and the particle size of the packing is 40-60. Samples can be loaded on solids and liquids, and fractions can be collected manually.
After more than 20 years of development, the Flash column has been widely used by people as conventional purification and separation equipment, such as Glaxo, Pfizer researchers have hundreds of Flash chromatography devices, and many instrument manufacturers in the world provide a full set of Flash chromatography device.
In recent years, due to the intensification of scientific research competition and the increase in labor costs of laboratories, a higher degree of automation and separation speed have been required, resulting in automated Flash column, with devices equipped with columns, chromatography pumps, detectors, automatic fraction collectors, and workstation. Some instruments also have a gradient elution system, a column switching system, and an automatic sampling system.
The optimized conditions can be selected to achieve unmanned operation, which greatly reduces labor costs and speeds up development. At present, some people in China use peristaltic pumps for infusion and separation with plexiglass columns. Strictly speaking, they cannot be separated from small molecules of the organic phase, but only for biochemical separation, otherwise, the instrument will be damaged.
The Flash column has many advantages compared with others.
1. Fast speed
2. A large amount of preparation: at least double the amount of sample than the same diameter HPLC preparation column.
3. Low cost and the use of solvent saves more than the glass column, the silica gel column can be used multiple times, saving the amount of silica gel.
4. Easy to use: no special solvent treatment is required, the sample can be applied by the dry method, and the person does not need special training.
5. Compact size
6. High reproducibility.
The effect of chromatography mainly depends on the optimization of the elution solvent and the packing effect of the column. When dealing with the relationship between preparation and HPLC, the following principles should be followed:
(1) When only Flash column can be used, there is no need to prepare HPLC
(2) First use Flash column, purification and then preparative HPLC
Other usage techniques include:
① First select anti-solvent and load by TLC
② Using short thick column (diameter: length ≤ 1: 7)
Also, its features include various available phases: C8, C18, Silica, NH2, CN, Alumina Acidic, Alumina Neutral, Alumina and it can withstand the pressure of 100ps.