Resurrecting partially damaged Cyano columns

[tapira1]

Hi,
Have a cyano column which was suffered some damage. They are too expensive in this corner of the world. Would like to know if there is any procedure to chemically endcap this column in situ (passing by an endcapping solution under certain conditions, please provide me with directions and details). It will not be used for any critical prupose, just for a univestity HPLC class.
Thank you in advance.

[mardexis]

You might be able to do this but it would probably be easier and cheaper to just buy some more cyano material and repack the column. You can buy small super cheap materials from column engineering http://www.column-engineering.com/ or a few other suppliers. Just take off the column end and push solvent through to empty the column. You can use an empty semiprep column as a slurry reservoir to repack. I can send you more details if you like. marc.foster@lifetech.com

[Gerhard Kratz]

Hi,
Have a cyano column which was suffered some damage. They are too expensive in this corner of the world. Would like to know if there is any procedure to chemically endcap this column in situ (passing by an endcapping solution under certain conditions, please provide me with directions and details). It will not be used for any critical prupose, just for a univestity HPLC class.
Thank you in advance.

Hi tapira1,
if you are lucky the damage is only at the column top. To repair that take some packing material out of the column, my recommendation is 5mm of the packing in the column. If you have CN packing in bulk you can use it, or if possible, use some large particle glass beads, 20 to 30 µm. Than use the column in reversed flow. Hope that will help. With kindest regards. Gerhard[/quote]

[rhaefe]

Another possibility if the damage is confined to the top/inlet of the column (and no void has formed): Run it against the original flow direction. The manufacturer can tell you if inlet and outlet frits are of identical porosity.
They usually are of the same prorosity.

[tapira1]

Thanks to all for the constructive answers. I wonder how can I make sure the damage is at the beguining (head) of the column and that not all the column is damaged. What I am noticing is that the column is still separating the analytes, however, peaks have tails, retention times are increased and a couple of peaks elute in "reversed order".
Will appreciate your hints and excuse me for my ignorance.
Thanks a lot to all in advance!!!