Message-Id: <v03007811af13e95bb709@[131.215.234.49]>
Date: Tue, 28 Jan 1997 10:35:39 -0700
To: "abrfhyp@cco.caltech.edu" <abrfhyp@cco.caltech.edu>
From: "Dirk S. Krapf" <krapf@cco.caltech.edu>
Subject: Re: Sparging for HPLC (fwd)
Date: Sat, 25 Jan 1997 18:38:14 -0500 (EST)
From: Umit@AOL.com
To: Recipients of ABRF List <abrf@aecom.yu.edu>
Subject: Re: Sparging for HPLC
Adam,
Like Ulf Hellman, I have given up on sparging HPLC solvents, and do not degas
them except when the salt containing buffer (i.e. NaPO4, pH 6.5) is being
filtered through a 0.2 um filter.
However, there is a caviat: I have been using an HPLC with high pressure
mixing and no proportioning valves.
If you have an HPLC with low pressure mixing you may have cavitation and
hence, bubbles in the system. Putting your bottles above the HPLC pump inlet
and using >1/16 inch feeder lines may reduce the chances of cavitation.
Remeber that chromatographic grade Helium is rether expensive, and cylinder
demurrage charges are added as long as the tank is in your posession.
umit yuksel
In a message dated 23.01.1997 19:03:14, you wrote:
>Hi Adam,
>I do not know if you have a very particular type of samples, but for my
>types, peptides and proteins, nowadays in the low microgram range, I have
>not bothered about any sparging for 10 years. The problems with out-gassing
>have been conveniently solved by a flow restrictor AFTER the UV-cell, giving
>just enough back pressure to keep gases in solution. I haven't even
>de-aerated my solvents. For the Beckman Gold, I had one little gadget made
>that simply squeezed the outlet teflon tubing to give some 3-4 bars. The
>Smart pumps have a restrictor built in. Then again, maybe some pump makes
>require sparging...
> /Ulf