Hello all.
Not wanting to contradict Thomas, I also run a Porton/Beckman and
use the HP/Agilent PTH-columns. I too usually find that 6 -12
months is a reasonable lifespan for these columns.
However last year, I noticed the same problem that Sandy reports
after returning from a 2 week break. The entire PTH profile of
a relatively new (ca. 8 weeks) column had changed beyond
recognition. I needed about half the amount of acetate and about
twice the amount of dil. TFA that I'd previously been using in my
buffer to restore separation.
But the most noticeable thing was that all the peaks beyond Pro
were virtually non-existent! My only solution was to inject
with DMSO then perform 24h of repeated PTH standards.
Unfortunately at best I was only ever able to recover the latter
peak heights to about half their former size, the column was
never the same again.
I've left these columns unattended (in ca. 90% CH3CN) before
without major deterioration, in fact I still do. The last batch
of samples ran before that particular break were indeed blotted,
so perhaps SDS may have contaminated / poisoned the solid-phase.
Good luck with your search for a solution.
Regards, JG
**********************************
Dr J. Gray
University of Newcastle Upon Tyne
Molecular Biology Unit
3rd Floor Cookson Building
Framlington Place
Newcastle NE2 4HH
United Kingdom.
Tel. / FAX : +44 (0) 191 222 8612
Email : joe.gray@newcastle.ac.uk
**********************************
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