The difference of Chromatography Column and Guard Column
The merits of the chromatography column need to use technical indicators to evaluate. Qualified chromatographic column evaluation report should give the basic parameters of the column, including the type of filler(say sorbent), column length, column efficiency, particle size etc.
The system for evaluating the column of the liquid chromatography should meet quite high requirements. On the one hand, the medium dead volume of the chromatographic instrument equipment system should be as small as possible. On the other hand, the sample and operating conditions used should be reasonable. Samples of chromatography columns under conditions can be completely separated and have an appropriate retention time.
The guard column is a column with the same stationary phase as the analytical column at the inlet end of the analytical column. It can be replaced easily and conveniently, so it can serve to protect the life of the analytical column. Although the use of the guard column will cause the analytical column to lose a certain column efficiency, changing an analytical column is not only wasteful, but also has a negligible effect on the chromatography system. Therefore, it is advisable to lose even a little bit of efficiency.
The thermostats commonly used in high performance liquid chromatography include three types: electric heating, incubator, and water bath. The maximum temperature required during the actual constant temperature process is no more than one hundred degrees, or the analysis of the mobile phase will be impossible after gasification. Appropriately increasing the column temperature is beneficial to reduce the viscosity of the solvent and increase the solubility of the sample. Changing the degree of separation is also a necessary condition for the stable and repetitive retention of values, especially for the analysis of sample samples that require high-precision determination of the retention volume.