For those still interested:
I have run a similar system on an ISOPREP 18 preparation
line for some years now.
The small Hokko beads are not suitable since they cause
blocking of capilaries and leaking solenoid valves. The larger
(1mm) beads, as suggested by Len, seem much better.
The only modification to Len's system I can suggest, is
direct pressure control of the hydrogen gas in the
equilibration vessels. Makes gas manipulation a wee bit
easier.
Preparing a working standard with 50ppm H/D is quite
laborious though.
Siep Talma

---------------------------------------------------
AS TALMA
CSIR-Environmentek
PO Box 395
0001 PRETORIA    South Africa
Tel +27  12  8413402   Fax +27  12  3491170
Email [log in to unmask]
----------------------------------------------------------

>>> Len Wassenaar <[log in to unmask]> 8/8/97
3:47 pm >>>
For those interested:

With only very simple, inexpensive hardware modifications
we have been able
modify our Micromass Isoprep-18 CO2-water equilibrator
(linked to an
Optima) to successfully run automated H2-water
equilibrations.  Results for
deuterium are typically better than zinc reduction. We have
run hundreds of
water samples for deuterium over the past 6 months with
excellent results.

We've posted a complete "How-to" document with photos on
our Web page at
the following URL;

http://ecsask65.innovplace.saskatoon.sk.ca/isotope/page15.html


Len Wassenaar