by
lmh » Mon Jul 07, 2014 9:54 am
Tom's right. Try putting some flow through the column and see what happens to back-pressure. If it is vaguely normal, try running a few test standards, and only panic if the results are consistently rubbish.
If the back-pressure is too high, yes, by all means follow Agilent's wash procedure, but if you've put a really strong solution of something through the column you might want to try a nice slow flow of nearly 100% water first, and gradually build up the flow rate as the back-pressure (hopefully!) comes down.
But the bottom line is that if you've killed the column, really really don't worry. Based in the UK I note that the columns I use generally cost somewhere between £400 and £1000, so if I've got 500 injections out of a column, the worst-case scenario is that killing it has cost me £2 per injection (and most columns do a lot more than 500). This is probably less than I spent on plastic-ware and vials during the preparation of the sample, and it's certainly irrelevant compared to my time. I also notice that some non-specialist groups buy a column, and it becomes a treasured lab asset, passed lovingly from Father to Son, from Mother to Daughter, and there is an expectation that it will carry on for ever. Columns are consumables. They deteriorate. Sometimes accidentally destroying one can be a good thing, if it's actually so old that resolution has already slumped.