Maintenance of chromatographic separation column
Chromatographic separation columns play an important role in the separation of high-performance liquid chromatography, so the maintenance of chromatographic separation columns is very much needed. Appropriate maintenance not only increases the service life of the chromatographic separation column, but also greatly reduce the cost of research.
Select the appropriate sample preparation method to ensure the good solubility of the sample to be separated. Remove as much as possible factors in the sample that may affect the life of the column, such as heavy metal ions, mechanical particles and some strong adsorption pigments, and some residues that affect the life of the column. It is better to filter the sample firstly. As for the solid sample, the oil pump is pulled dry after mixing. Reducing the strong solvent residue improves separation effect significantly.
Avoid high-pressure shock. Generally the column can withstand high pressure, but can not stand the sudden change of high-pressure shock, which will change the column bed volume, affecting the efficiency of the column. The high-pressure shock might caused by slow rotation of sampler valve, pump starts too fast, column switching and other operations.
Choose the appropriate column. We know that the choice of chromatographic separation column is mainly based on two points, one is based on the size of the molecular weight of the component to be measured; the other is based on the mobile phase conditions, including pH, ionic strength and solvent polarity.
Rinsing the column after each analytical work is a good habit, which can greatly improve the life of the column.
If buffer salt is used for the reversed-phase separation column, the buffer salt in the column must be washed out with a low proportion of organic phase, then the column is washed with a high proportion of organic phase, and the separation column is finally stored in a high proportion of organic solvent. In addition, the column must be stored in a neutral pH mobile phase, instead in a strong base or acidic system.
For the normal phase silica gel column, according to the nature of the sample used to select the solvent with a good solubility of the sample to be washed. But take into account the destruction of methanol and other solvents on silica gel, control the methanol content of 10% or less, or use the system of alkane and isopropanol (50:50) to wash a silica gel column. Finally, it’s stored in a system of n-hexane and isopropanol(90:10).