HI Antonella--
Just caught Zach's reply--good stuff...
If you want to look at some other things, since I already wrote this
out, you can check the isogeochem archives at:
http://list.uvm.edu/archives/isogeochem.html. (three cheers for Andrea
Lini for maintaining the list)
there was a discussion around 6/03 about water in TC/EA (Glassy C
Tubes...Tim Howe's response mentioned running serum samples), also 10/03
on "high salinity waters", 4/04 on "d18O of water"
Bottom line, you need to be able to clean the syringe very
well--otherwise you'll have bad memory effects. That's where we hit a
wall in our short foray into running liquids on a TC/EA. Remember that
this will give you total H and total O, not just H and O of the water
(important if you're doing stable isotope tracer studies, otherwise the
water at ca. 55 molar will probably overwhelm everything else). A cold
trap would be useful to remove any nasties that might form from your
samples (H2 and CO will pass through liq N2 trap, see Gehre and Strauch,
Rapid Commun. Mass Spectrom. 2003, 17 1497-1503).
good luck
take care
gerry
antonella wrote:
> Dear All
>
> I'm approaching to test reproducibility, linearity and memory effect
> in deuterium and oxygen measurement in TC/EA .
> I have biological samples, like plasma, urine, saliva, and I have to
> test _delta 2H and 18O of water contained in these samples_. I think
> that the presence of organic compounds or salts can affect the delta
> of water, but very few papers are published about this.
> Has anyone experience with TC/EA and these matrices? If so, how do
> you remove organic or/and salts?
> Otherwise, can you suggest me some good references or someone that
> works with tc/ea and biological samples?
> I hope somebody can help me.
>
> Thanks and best regard
> Antonella
>
>
>
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