Using HPLC Columns

In order to preserve the life of your silica-based HPLC columns, you need to use, clean or store them correctly. If you need to store your HPLC columns overnight, make sure they are in the eluent which was used in the most recent analysis. If you need to store your columns for about two days or over the weekend, the columns will need to be regularly flushed with water to prevent bacterial growth. 

For storage that is more than just one weekend, you will need to store your silicon in a solvent which is aprotic. Ideally, the storing solvent you use will be Acetnitrile. The liquid content cannot be higher than fifty percent.  Before you flush the column with Acetonitrile, you need to ensure that all the buffers have been rinsed out. This is because salts used as buffers are not Acetonitrile soluble and do block both the column and the capillaries.

A column's equilibration time depends on its dimensions. Generally, columns are equilibrated after rinsing them or flushing them out with twenty volumes. Equilibration time for various column dimensions are fifty eight minutes for columns which are 250 by 4.6 mm, thirty five minutes for columns which are 150 by 4.6 mm, twenty three minutes for columns which are 100 by 4.6 mm and twelve minutes for columns which are 50 by 4.6 mm.

If you increase the flow rate, it is possible to accomplish equilibrium in a shorter period of time. If no chromatography has been done, doing this should not be a problem. However, remember that you need twenty column volumes, to guarantee one hundred percent equilibrium.

Remember that HPLC columns based on polymer display increased stability in terms of pH but a decrease in low mechanical stability. This is in comparison to columns which are based on silicon.