Conventional reversed phase chromatographic column < clea

Recommended steps for column cleaning and regeneration:
With the increase of pressure, the peak shape of chromatographic column will change, such as serious tailing, shoulder peak or even peak bifurcation, and the resolution will decrease, which strongly indicates that the column is polluted. The following steps can be used:
1. If the system is connected with on-line filter and protection column, check and replace the online filter and protection column first. In daily operation, when the pressure increases by 10% or the column efficiency decreases by 10%, the on-line filter and / or protective column should be replaced.
2. Use a high proportion of organic solvents for flushing (please pay attention to avoid salting out, usually use the gradient rise method, and then maintain at a high proportion or even 100% organic solvent). This operation usually removes most of the contaminants.
3. If organic solvent cleaning can not solve the problem, the following methods can be used for cleaning and regeneration of chromatographic column. Choose the cleaning method according to the nature of the sample and the pollutants you know. Clean the chromatographic column with 20 times the volume of the column (i.e. 80 ml for a 4.6 x 250 mm column). Raising the temperature of the mobile phase to 35-55 ℃ C can improve the cleaning efficiency. Of course, the washing time and flow rate can also be adjusted according to the conditions of the column.
4. Backflushing of chromatographic column can be considered, especially when the problem is that the pressure rises sharply, indicating that there is particulate matter directly blocking the sieve plate at the inlet end of the column. During operation, the chromatographic column is reversed and disconnected from the detector. Use a low flow rate of 0.2ml/min, flush overnight, and block the inlet and outlet of the detector to prevent the solvent from volatilizing and generating bubbles. Or, open the column carefully and replace the sieve plate directly at the column inlet. be careful! This kind of operation requires skills, only as the last attempt when the problem can not be effectively solved, or for the reference of some experienced analysis operators. At present, most chromatographic column tail sealing technology is very high, and the packing is becoming more and more fine. Opening the chromatographic column is not a safe operation. There is a considerable probability that the chromatographic column will be directly scrapped. The operation should be careful.
PS: pay attention to prevent buffer salt out, and adjust it to a mixture of isopropanol and water in proper proportion. Unless you ensure that your system is fully compatible with tetrahydrofuran and n-hexane, tetrahydrofuran or n-hexane should only be used when the chromatographic column cannot be cleaned with reversed-phase organic solvent such as acetonitrile. Reduce the flow rate and operating temperature, and minimize the amount of tetrahydrofuran and n-hexane in the system Exposure time in hexane.
For more related technologies, please consult MS technologies technicians