help ------MS - analysis

[Kadi]

Dear all ,
Is there any better way to find out how much of 13C and 15N labelled
in my sample by mass spec.

current mass spectrum of my sample when comapred to unlabelled sample
shows that it has been labelled by both 13C and 15N.

but i wondering how could i calculate to know how much of each nuclei
would be labelled.

my sample is isolated from bacteria, so it not like chemical
synthesis , where i could be sure of 100 percent conversion etc.

if any software could simulate the spectra , plz leme know so that i
can simulate the spectra for 13C and 15 labeling pattern seaparetley
and compare them to get some rough idea.

will be very happy if some one could help me out.

thanks in advance.

doei
kadi

[Sassman]

Post by Kadi
Dear all ,
Is there any better way to find out how much of 13C and 15N labelled
in my sample by mass spec.
current mass spectrum of my sample when comapred to unlabelled sample
shows that it has been labelled by both 13C and 15N.
but i wondering how could i calculate to know how much of each nuclei
would be labelled.
my sample is isolated from bacteria, so it not like chemical
synthesis , where i could be sure of 100 percent conversion etc.
if any software could simulate the spectra , plz leme know so that i
can simulate the spectra for 13C and 15 labeling pattern seaparetley
and compare them to get some rough idea.
will be very happy if some one could help me out.
thanks in advance.
doei
kadi

Hi Kadi,

Your question is not very clear, but I think this software might be able
to help you:
http://thor.hu/download.php?view.3378
Look under tools for isotopic composition modelling.
---
http://www.analyticalchem.com

[Chip]

The Isotope Ratio Calculator in Mass Spec Tools can simulate isotopic
patterns and peak shapes at any resolving power, including overlapping
interferences from other species. Isotope enrichment is calculated
through the user-defined isotopes. The program is part of a suite and
is not free, but you can download a demo version:

<http://www.chemsw.com/13057.htm>

Chip

Post by Kadi
Dear all ,
Is there any better way to find out how much of 13C and 15N labelled
in my sample by mass spec.
current mass spectrum of my sample when comapred to unlabelled sample
shows that it has been labelled by both 13C and 15N.
but i wondering how could i calculate to know how much of each nuclei
would be labelled.
my sample is isolated from bacteria, so it not like chemical
synthesis , where i could be sure of 100 percent conversion etc.
if any software could simulate the spectra , plz leme know so that i
can simulate the spectra for 13C and 15 labeling pattern seaparetley
and compare them to get some rough idea.
will be very happy if some one could help me out.
thanks in advance.
doei
kadi