Dear ??

There is a much easier way to get stable isotope ratios of rat breath. You
can refer to our papers (Luz et al (1984) GCA 48: 1689-1693 and Luz and
Kolodny (1985) EPSL 75: 29-36. All you need to do is to place the rat for
five minutes in a sealed plastic container. The air in the container will
become enriched in CO2. You can the sample this air into your exutainer tube
(or something similar) and run on the mass spectrometer.

Good luck,


Boaz Luz

>Dear listmember,
>
>I want to determine delta values of rat breath, on rats treated with
>13C-labeled palmitic acid. We think the easier the better and simply
>tried the following procedure. Comments and suggestions for improved
>method appreciated as well as aspects on breath analysis on GCCIRMS
>without chromatographic separation of the present gases (se below).
>Suggestions on suppliers of labeled bicarbonate standards (delta from
>-30 to about 100) appreciated as well.
>
>1. Breath was continuously absorbed in a 500 ml 1M NaOH solution for up
>to 120 minutes. All CO2 should be absorbed as bicarbonate.
Prof. Boaz Luz
Institute of Earth Sciences
The Hebrew University of Jerusalem
Jerusalem 91904, Israel
Tel. 972-2-6585224
Fax. 972-2-5662581