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Hi all
I am doing some work on Adrenaline injection (1mg/ml) stability. I
would like to
do some work on the LC/MS ( I want to analyse degredation products of
Adrenaline), however I can't use the mobile phase that we currently use for
Adrenaline analysis as it contains, amoungst others, a buffer, and as far as I
know, a mobile phase containing buffers (and certain other constituents) can't
really be used for LC/MS work.
Does anyone have any experience with adrenaline analysis on LC/MS, and if so,
what mobile phase did you use?
Bronwen W
QA Pharmacist
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G'day from Germany!
I have never analyzed Adrenaline with LC/MS, but we often work with LC/MS,
though. You are right, generally the mobile phase should not contain
buffered solutions. But it is no problem at all if the buffer is volatile,
though. For example, we often use Ammoniumacetate as buffer solution. Both
components of the buffer - ammonia and acetic acid - are volatile and will
be evaporated in the heated capillary which is located at the "entrance" of
the mass spectrometer.
I don't know which pH you use in your HPLC-separations but perhaps you can
simply replace your existing buffer with a volatile one. I assume you are
working at pH 8 or so? Perhaps it is possible to mail me the composition of
your mobile phase so that I can have a look at it?
In many cases it is possible to work without any buffers (e.g. replacing a
buffer with double-distilled water). In your case you might also try to add
triethylamine to your mobile phase (often helpful when analyzing amines).
I hope this information proves useful.
Best regards,
Dirk Schepmann
Dirk Schepmann (Pharmacist)
University of Muenster Phone: +49(251)83-33343
Department of Pharmacy
Hittorfstr. 58-62
49149 Muenster
GERMANY
E-Mail: schepma.at.uni-muenster.de
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Bronwen:
LC-MS work typically uses a mobile phase containing formic or acetic
acid if low pH values are needed. Ammonium formate (adjusted with
ammonia or formic acid) is commonly used where a higher pH is needed,
as it is volatile.
Richard
Richard J. Prankerd, PhD
Senior Lecturer
School of Pharmacy Phone: INT + (617) 3365-3179
University of Queensland Fax: INT + (617) 3365-1688
St Lucia QLD 4072 richard.at.pharmacy.uq.edu.au
AUSTRALIA http://www.uq.edu.au/pharmacy/rprank.html
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David Bourne (david@boomer.org)