Column age

[Mattias]

Hi,

Do columns "degrade" over time, even if they have never been used? We have got a full box of never used columns from one of our sites, the oldest column seems to have been manufactured in 1997 (Lichrospher C18). The column type is still used in one of our really old LC methods.

Is it just to throw away? Otherwise we have a stock that will last my life time...

[Victor]

I think the answer to your question depends on a lot of things, like whether the columns were physically shocked during storage, the temperature etc. One factor is likely to be the storage solvent. ODS columns can undergo a slow hydrolysis or methanolysis if stored in methanol-water mixtures which results in loss of the bonded ligand. Some enlightened column manufacturers have shipped their columns in pure acetonitrile for many years which (also in my experience ) preserves the performance of the columns very successfully. I have a feeling that in 1997 it might be more likely that methanol-water was used; probably it will say somewhere on the box, but maybe it won't!! Quite often the columns are stored in the solvent used for the test chromatogram if no other information is given. I'm afraid there is probably no option but to run a test on the columns to see how they compare with fresh ones. This should not take long because the best test is your own sample that you will use for the analysis. I would do this, but possibly some might think this was not cost effective.....

[danko]

Hi Mattias,

What a coincidence. We were in the exact same situation a month ago, even the columns age was the same (from 1997).
We conducted the following test: Prepared the mobile phase needed for the particular analysis, installed one of the currently used columns, ran a couple of runs, calculated R, N and T and than installed 3 consecutive “oldâ€

[DR]

If they weren't abused (kicked, dropped etc.), they are probably fine.

If you prefer to get rid of them, I'm sure there are several regulars here who would appreciate knowing when you plan to toss them out so that they can raid your dumpster.

[Mattias]

I am actually running one of the old methods as we speak, so I hooked up one of the oldest columns and did a testinjection. I couldn't see any difference in plate count or resolution compared to a new column. It was actually slightly better... Maybe they need to sleep a while like good Bordeaux (just kidding)!

I couldn't find any info of what the columns have been shipped in. No test chromatograms either (maybe they didn't do that 10 years ago).

[Uwe Neue]

If the columns have been stored in acetonitrile (and have never been used as a replacement for a football), they are likely to be as good as new.