||SEC Columns need to be used with care in order to increase their life.
- Make sure that you do not exceed the limit column pressure established in the column Quality Certificate, otherwise the high pressure can cause the gel to collapse. You may want to set the highest pressure alarm at 70-85% of the limit especified by the manufacturer.
- Columns packed polymeric gels are more susceptible to damage than the silica gel columns
- Always use a pre-column.
- Frit blockage can be prevented using proper sample preparation, using 0.45 micron filters before injection. In cases that the frit becomes blocked, ensure that the column is compatible with reverse flushing, orif reverse flushing does not work, carefully replace it. Make sure you do not touch the filling material. If you notice a void between the packing and the frit, fill it with gel from an old column.
- Remove all salt solutions with pure solvents and plug tight with the original end plugs.
- Store the columns in the solvent used during shipment; If the column was shipped and used in THF or CHCl3 you can store the column in toluene as well. Toluene has the advantage of a very low evaporation rate. Columns shipped in DMAc or DMF must be stored in DMAc or DMF.
- It is good practice to keep columns with volatile mobile phases in a refrigerator (4°C) after use to prevent solvent evaporation. Warning never let the column temperature fall below the freezing point of the storage solvent. This can destroy the stationary phase.
- Occasionally solvent is lost during long-term storage or due to high storage temperatures. When the expected pressure does not build up or the pump constantly re-regulates the flow, it is an indication of a partially evaporated column solvent
Recovering a partially dry column
To re-wet a partially dry column, install it in the reverse direction (to prevent damaging the packing). Using a flow of 0.1 ml/min, fill the column until no more bubbles appear at the column outlet. Change the column to the correct flow direction and again use 0.1 ml/min for 1h. Then you can slowly increment the flow rate, systematically, using 0.2 ml/min steps.