Dear listmember!

Can you give me some advice or comments on the following questions?

I have a Finnigan Delta plus with a GC-Combustion unit. Collegues want
to perform multiple tracer experiments in rats (and eventually humans)
using stable isotopes of C, H, O and N together with radioactive tracers
of at least C and H if possible. We want to look at 
1. specific compounds (palmitate in lipids, glucose, glycerol, leucine) 
2. total enrichment in local tissue 

Original sample amount is limited to less than 100 mg plasma or tissue
or micrograms of the specific compounds resulting in nanograms on
column.

The simple question is - can I upgrade my system and do hydrogen and
oxygen meaurements on either specific compounds (after GC separation or
other sample preparation) or on a bulk sample with a precision better
than a few per mil delta and peak enrichemnts of let say 100 per mil
delta - Or would I be better of with an ordinary GCMS?? If so, what is a
typical minimum enrichment level that can be detected with some
precision, in terms of delta per mil?

The only commercial systems I know about (but very little) that could
help perhaps are

1.Pyrolysis -CF-IRMS
2.D2O equlibration device
3. Elemental analyzer (for C,N S only)

(I have access to an (old) oxidizer that collects water and CO2  after
combustion of a sample in scintillation vials. It could be used for
preparation of 
D-labelled water I guess)

What can you suggest (to read and to buy)?

Do you know of suppliers for oxygen-labelled glucose, palmitic acid and
palmitate-triacylglycerol?

You may reply to my adress below

Best wishes and thank´s,
               Lars Löfgren

phone +46(0)31 7762381
fax +46(0)31 7763711
e-mail  [log in to unmask]
phone home +46(0)304 675720

Address:
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Bioanalytical Chemistry AB2
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