Overnight short-term storage: If the buffer capacity of your mobile phase is low, you may be able to leave it in the column overnight. However, it is typically recommended to pass the mobile phase through column at a very low flow rate. In this scenario, conditioning and/or re-equilibrium of the column can generally be skipped if you are keeping the same mobile phase that was used in the previous analysis.

Mid-term storage: After completing analysis, if the column is not being used for an extended period, it is typically recommended to wash the column out by passing through about 10 column volumes   of the mobile phase containing 10% organic solvent (recommended methanol) in water. This will help to flush the salts out from the column and also prevent the possible precipitation  of the buffer. After the salts and buffer have been removed, flush the column with 100% organic phase (e.g. methanol which is an excellent solvent to remove the biorelevant components) for approximately 15 column volumes . Afterwards, the column can be detached and sealed with end plugs, or it can remain attached to the instrument.

Long term storage: After a thorough mid-term storage cleaning,   it is generally recommended to use a storage solvent for the reverse phase column that has a high vapour pressure. 

This mitigates the risk of column dry-out if end plugs were not tightened enough. Furthermore, the storage solvent should also be capable of inhibiting the microbial growth inside the column after using biorelevant media. Our preferred storage solvents to preserve the column are methanol: water (80:20) and isopropyl alcohol: water (80:20)