Jeni,
Are you using an 1100 autosampler, and if so have you checked the needle on the
injector or the plumbing on the injector for plugs? There may be a plug in one of
these lines that is causing the high pressure.
Mike
Michael Curtis
Biotechnology Development
Bristol-Myers Squibb Company
Syracuse, NY 13207
315-432-2209
Jeni Lauer-Fields wrote:
> Hi,
>
> I've been having some recurring problems with our HP1100 and we (the Agilent
> tech people and myself) can't seem to figure out what's going on. I thought
> maybe somebody here could help.
>
> We normally run RP-HPLC and have encountered no difficulty with the instrument.
> Recently we did some size-exclusion chrom. with 150mM salt and the fun began. It
> ran without incident for about 2 weeks (running nearly 24h/day). Slowly the back
> pressure built up until it reached the upper limit for the column. I follwed the
> column directions and washed it with 0.5N NaOH follwed by buffer follwed by 20%
> MeCN. Lots of stuff came off the column but the back pressure was still too
> high. I narrowed it down to the HPLC itself and washed it (without the column in
> line) with; hot water, dilute TFA, dilute HCl, dilute HNO3, and various
> concentrations of MeCN (not in that order). The nitric acid killed everything.
> The system was completely blocked, so I called in a service person. After two
> visits he changed the pump seals and all of the frits and it ran for a couple of
> days before the back pressure problems crept up again.
>
> We can't quite figure out what is happening. Something is clogging up the
> system, but I'm taking all precautions that I can think of to stop it from
> happening. I'm sterile filtering all buffers on a weekly basis. I've changed the
> purge valve frit every couple of days and I've cleaned the frits in the solvent
> bottles at least twice since the trouble began and I've changed the filter on
> the column (which looked like it was dragged across the floor).
>
> If anybody has a clue what happened to our instrument and how I can fix it I'd
> love to hear about it. The instrument is under service contract so I don't have
> to worry about the cost of repair, but I don't want to waste Agilent's time and
> money fixing the symptoms rather than the problem itself. Changing frits is
> definately not curing the problem.
>
> Thank you in advance for any assistance you can offer.
>
> Jeni
>
> Janelle Lauer-Fields
> Department of Chemistry & Biochemistry
> Florida Atlantic University
> 777 Glades Road
> Boca Raton, Florida 33431
> 561-297-2094/Fax 561-297-2759
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