Dear All,

For what it is worth....

In addition to what is reported in Rapid Communications in Mass
Spectrometry (v 14, p 293-297), here are the results of gas [either
0.5 or 1% CO2 in He, I forget which] analyzed with the gasbench II
and stored in vials from July 14, 1999 to Dec. 21, 1999.

Labco septa with borosilicate vials:

d18O:  33.68 ± 0.283 per mil [n=4]
d13C:  -28.14 ± 0.46 per mil [n=4]



Labco septa with labco [Na-glass] vials:

d18O:  26.72 ± 0.38 per mil [n=4]
d13C:  -28.36 ± 0.14 per mil [n=4]

At the time this experiment was done, I believe the Labco vials that
were shipped to me had a "silicone" coating that appears to be
capable of exchanging oxygen.

I like the Labco cap/septum assembly, but I only use them with
borosilicate tubes.
--

********************************
Steve Nelson
Dept. of Geology
S389 ESC
Brigham Young University
Provo. Utah  84602

voice:  1-801-378-8688
lab:    1-801-378-5124
FAX:    1-801-378-8143

Q.  How do you spell "scapegoat"?
A.  Wen Ho Lee.
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