Dear Fulvio,
At 03:40 PM 5/17/01 -0500, you wrote:
>I have been using 0.02%conc. HCl v/v in place of TFA,for the past four to
>five years.It works like a charm.Considering that dilute halides can affect
>stainless steel,I keep that in mind,and I do not let anything in the acid.
> I have no idea why I used 0.02%,and I am adding it also to solvent B,which
>is 90%acetonitrile.I remember that way back when Waters Associates,I
>think,suggested the use of 6mM HCl in place of TFA,which is about right for
>0.02%.
> Unless you rust up your system,HCl is completely transparent.
>Fulvio Perini
>UNMC
>986805 Nebraska Med.Cntr.
>Omaha,NE 68198-6805
Yes, I have a Waters flier from 1990 (I really need to clean out my
files!) in which they suggest using 6mM HCl (0.05%) instead of TFA if one is
looking for slightly different selectivity. I use it occasionally when I
have a need for rechromatography of peptides and have been pleased with the
results.
As you say, it's very important to flush the HCl out of a stainless
steel system when done. Rust never sleeps.
Carol
Carol Manley Beach, Ph.D.
Protein Sequence Analysis
Macromolecular Structure Analysis Facility
232 Combs Cancer Research Building
University of Kentucky
Lexington, KY 40536-0096
cmbeach@pop.uky.edu
(859)257-4932 (office)
(859)257-4475 (lab)
(859)323-3909 (FAX)
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