I have looked for the max allowable psi everywhere but none could be found. Anyone familiar with this old Waters Part No.86344 ?

Btw, the column (in the above) was previously used but not sealed. Any opinion about a possible (best case) restoration of this column?

Thank you for any help,
Joe Rongen
Ont, Canada
joe@alpha.to

Joe,

We are using the Nova-Pak C18 (cartridge), and the maximum psi we allow is 2000. But you could ask the Waters people if you want to know.

Using a Nova-Pak column, you can use any pressure that your HPLC is capable of. If this is a cartridge column, the pressure is limited to about 4000 psi due to the o-ring seal.
Since you don't know what was in the column, I would start washing it with water, then methanol, and then you should be able to go to the mobile phase that you want to use.

Thank you for the replies.

I send 0.5 ml of water (at ~815 psi) through the column for about 5 hours and a few peaks appeared, after 3 hours - this was measured with a Waters 484 set at 2100 Angstrom. Roughly, how long should one wash an orphan column like this?
Are we talking days here...or till no more peaks appear in about...how many hours?

Thanks again, Joe

You've washed it with water for long enough, its time for the methanol.....

Plenty of time already, half an hour of each solvent is enough.