Joseph,
1. There is Karl Fisher titration for H2O and ion-chromatography for
counter-ions. Any contract analytical lab will do it.
2. Esters are not stable to HF cleavage. However I can imagine that
theoretically you can cleave some of the acid labile groups without ester
cleavage using low HF cleavage for a short time.
Michael Breslav
R.W.Johnson PRI
Spring House, PA
> -----Original Message-----
> From: Fuselier de la Claire [SMTP:devildog@mailhost.tcs.tulane.edu]
> Sent: Thursday, January 20, 2000 6:59 PM
> To: Recipients of ABRF List
> Subject: Pepsyn: A couple of questions
>
> What is the best way to quantitate the amount of H2O and counter-ion in
> a sample of lyophilized peptide?
>
> Are esters stable to HF cleavage?
>
> --
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> Joseph A. Fuselier
> Peptide Research, SL12
> Tulane University School of Medicine
> 1430 Tulane Avenue
> New Orleans, Louisiana 70112 USA
> 504.588.2296
> (fx) 504.584.3586
> devildog@mailhost.tcs.tulane.edu
>
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
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