Back to the Top
The following message was posted to: PharmPK
Hi all,
I would like to quantify proline and valine by LC/MS and I would try
to use
a basic mobile phase (pH 7.5).
But I can't find a volatile buffer, and with ammonium acetate and
ammoniac,
it's difficult to set the pH with precision.
Does anyone have a quick and good solution?
Thanks.
Fabrice Guillet
XENOBLIS
[From Perrin and Dempsey (1974 ;-) - Volatile buffer in pH 7.5 range:
triethanolamine/HCl,ammonia/formic (or acetic acid), trimethylamine/
CO2, triethylamine/CO2 - db]
Back to the Top
The following message was posted to: PharmPK
You want to keep adducts to a minimum- use MeOH rather than ACN, reduce
Na in all media. suggest TFA/NH4Formate with MeOH as the organic
Ed O'Connor, PhD
Technical Director, Immunoanalytical
Tandem Laboratories
115 Silvia Street
West Trenton, New Jersey
609-228-0243
Back to the Top
The following message was posted to: PharmPK
On a recent method development, I used two different journal articles
that
cited using TFA / NH4OH with MeOH as organic.
Michele
Back to the Top
The following message was posted to: PharmPK
How about ammonium carbonate?
The following message was posted to: PharmPK
You can also try ethylamine or dimethylamine
Back to the Top
Dear Fabrice,
I have successfully used triethylamine and acetic acid or formic
acid. They are all volatile and promote strong ionization.
Still, I would suggest a fairly low concentration, so don't exceed 10
- 15 mM.
Best regards, Jurij Trontelj
Want to post a follow-up message on this topic?
If this link does not work with your browser send a follow-up message to PharmPK@boomer.org with "Basic Buffer for LC/MS analysis" as the subject | Support PharmPK by using the |
Copyright 1995-2011 David W. A. Bourne (david@boomer.org)