Sorry for the delay, you are absolutely right, these are important
factors I forgot to mention...
The cows were bought from a farm near Quebec City. We have been feeding
them with a mixture of 50 % corn sillage, 35 % grass sillage and 15 % of
concentrated feed (moulee).
They are drinking regular tap water which I did not analyse but it
should be close to the tap water I have in the lab having a deuterium
content of about -55 per mil VSMOW.
We are planning on using ring-D5 PHE. I'm not sure of the level of
enrichment we'll be aiming at... In our last experiment using 1-13C PHE,
not enough tracer was injected and the isotopic enrichment in protein
muscle was really small (3 per mil in th most). I guess that with more
labelled atoms, it will be easier to enrich the muscle protein....
We are analysing the bounded PHE of protein muscle with a GC-C-IRMS
system and the free PHE of protein muscle with a GC-MS system.
Thank you very much !
Professionnel de recherche
Departement des sciences animales
Tel. 418-656-2131 ext. 11411
Ste-FOy, Quebec, Canada
From: Dr W Meier-Augenstein <[log in to unmask]>
To: [log in to unmask]
Date: Sat, 22 Oct 2005 11:49:12 +0000
Subject: Re: [ISOGEOCHEM] 2H content of amino acids in animals
> Dear Alexandre,
> I hope you won't mind "answering" your questions with more questions?
> (1) Where does your cattle live and where does their feed and water
> from? (2) What kind of 2H labelled Phe do you intend to use, e.g.
> or chain-D2 and at what level of enrichment? (3) How are you planning
> analyse your 2H-labelled Phe, IRMS or MS?
> A bientot,
> On Oct 21 2005, Alexandre Myre wrote:
> > > Hi everyone,>> we are considering a tracer experiment on steers and
> > > cows using some 2H-> labelled phenylalanine tracer for muscle
> > > and plasma samples.>> I would like to know what type of isotopic
> > > signature I can expect from> background values... I would also be
> > > interested in amino acid 2H values> from other animals or human if
> > > someone have some...>> Many thanks !>> Alexandre Myre>
> Professionnel de
> > > recherche> Departement des sciences animales> Universite Laval>
> > > 418-656-2131 ext. 11411> Fax. 418-656-3766> Pavillon Paul-Comtois>
> > > Universite Laval> G1K 7P4> Ste-FOy, Quebec, Canada