Several Common Problems Of Flash Column Chromatography
As a replacement of too long column chromatography, flash column chromatography, also known as medium pressure chromatography was developed since the 1970’s. The aim of the method is to isolate a component from a mixture and purify it.
Different from the old long column chromatography technique which takes a long time and gets makes poor result, flash chromatography is highly recommended because of it high speed and neat resolution.
Flash column chromatography passes a sample through a column filled with a gel, which separates the sample with slightly smaller silica gel particles. And the pressurized gas is often used to drive the solvent through the stationary phase column.
Hawach provides a high purity stationary phased packed flash column with the full range of size. With the column cartridge made from medical grade virgin PP material and PE frits, Hawach flash columns can handle a larger amount of sample. The wide-open column top always helps easy sample loading, and each adsorbent int he Hawach flash column is packed by Hawach column packing technology. The empty flash column is online too.
Leakage Removal in Operation
Mobile phase leakage sometimes occurs during filtration, the possible reason is that the filter membrane is misplaced (a little biased) or the joint is a little misplaced, resulting in the flow phase leaking out of the gap. Therefore, during operation, a small amount of mobile phase should be poured into the bottle to observe whether the liquid is leaking and start filtering, if there is no leakage, the mobile phase should be added to the container gradually. Another matter needing attention is that the column should be flushed with pure water mobile phase as far as possible after operation, or the strong polarity of water will damage the column and lead to the decrease of column efficiency and accuracy.
Improper Combination Removal in Application
Read the instructions attached to the chromatographic column carefully before use, pay attention to the scope of application, such as pH range, mobile phase-type, etc. in the process of operation, it is better to use the required mobile phrase, protective column. When the flash column is not in use, rinse with formaldehyde, remove and close two stages of preservation, do not rinse column under high pressure and do not use silicon bond.
Flash column chromatography has been used widely in organic chemistry since it was first published. However, the guidelines of the flash column chromatography are not be translated or spread correctly. There are still several common problems when the experimenters do the experiments with flash column chromatography.
First, the increasing sampling size will lead to the reduction of the resolution. Compared with HPLC, the resolution of flash column chromatography is medium level. And thus the increase of the sampling number will only aggravate the situation, the reduction of the resolution.
Second, the optimum velocity depends on the length and width of the flash column and the properties of the gel. The longer and narrower columns will provide more theoretical plates to affect the flow rate.
Finally, the resolution is affected by the stationary phase. If the stationary phase or the gel arranged on the column is more homogeneous and has a smaller particle size, it provides better resolution. The smaller the particle size is, the larger the surface area is and the higher the resolution is.