by
lmh » Thu Aug 18, 2011 10:49 am
I tend to store C18 columns in 80% acetonitrile or methanol, the remainder being water with no acid or buffer. For other columns, follow the manufacturer's instructions. I don't use 100% acetonitrile because if the column has ever been in contact with anything slightly salty, if any trace of salt remains, there is just a slight danger it might gradually precipitate. This is probably just an unreasonable worry as it should have been washed!
As for the hplc system, most systems can be stored in almost anything for a month, provided it's not too corrosive. I've heard 50% isopropanol suggested. I would use anything acid-free and with sufficient organic content to prevent algal growth. If you have lines that have been used in buffers, I would not store their inlet filters in 100% organic; we had dire problems some years ago with Waters Alliances used with ion exchange when the inlet filters, even after extensive flushing, were put in 100% acetonitrile or methanol. I am guessing, but think that during flushing, most of the water takes the easiest route through the filter, and traces of salt remain in the less accessible depths of the filter. On soaking for longer periods in organic solvent, it migrates out and precipitates, and the result is unreliable check valves.
