<x-charset iso-8859-1>John,
sounds like the UV lamp is dying to me.
Ken
----- Original Message -----
From: <John.Holt@aventis.com>
To: "Recipients of ABRF List" <abrf@aecom.yu.edu>
Sent: Friday, May 18, 2001 2:20 AM
Subject: Prot seq & hplc
> The blank chromatogram on the 1090 LC of our HP G1000 Sequencer System
has
> a slope from 0 to 6mAU over the needed part of the separation. This slope
> appears to have increased steadily over a year or so. As others have
> remarked, the price of this is loss of sensitivity, which is now nearer
> 10pmole than the 1pmole that was previously possible. If this were simple
> rp HPLC, I would match the absorbances of mobile phases A and B
> experimentally by adding TFA to A (currently, B absorbs more than A).
>
> Can anyone tell me (a) if I'm right in thinking that the problem is no
more
> than absorbance mismatch, (b) if there's an acceptable fix (doesn't
require
> extensive re-tuning of PTH separation) and (c), if there's a better (more
> inert, or MS-friendly) chromophore to use than TFA to match solvents in rp
> HPLC?
>
> John Holt
>
> Analytical Sciences
>
> Aventis Pasteur
>
>
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