We purchased an Fisons VG Optima 3 years ago - a fine machine. We have had
no major  problems (other than a few leaky pneumatic valves and one board
replaced) and have run nearly 10,000 samples. We also bought the "Breath
Carousel" ((now superseded by Isochrom MS and hardware)) and react our
carbonate samples (DIC and solids) in Vacutainers. The results for 13C are
excellent with sample times of 7-8 minutes and up to 50 samples
automatically. The Optima design is excellent and the software is very good
(OS/2 based). If you ever want to do H/D, definitely go with the Optima. It
is as easy as loading a tuning file. I had about 1 year experience on the
DeltaS, also a good machine, but the software (ISODAT) is bizarre in
structure and at least 10 years behind. In terms of hardware the Optima is
probably a bit more delicate. In short, the Optima is the Prima Donna of the
two, the Delta is built as only a German would do it. 

A Note of Caution:  Fisons was recently bought by Thermo, the parent company
of Finigan MAT.  Its anyone's guess what will happen to Fisons VG, as its
been losing money in the past few years.



>
>I have been asked by a colleague/friend to give him advice on which stable
>isotope mass spectrometer to purchase for carbonate work.  The choice boils
>down to a VG Optima versus that of a Finnigan Delta-S.  Unfortunately, I do
>not have any direct knowledge of either beast as neither one of them is in
>our lab.  If anybody could shed some light upon this query (asap) it would
>be much appreciated.
>
>
>___________________________
>This message is from:
>
>Thomas Guilderson
>[log in to unmask]
>
>Lamont-Doherty Earth Observatory
>Rte. 9-W
>Palisades, NY  10964  USA
>
>^^^^^
>END
>
>
Len Wassenaar

National Hydrology Research Institute
Environment Canada
11 Innovation Blvd.
Saskatoon, Saskatchewan
Canada  S7N 3H5

tel: (306)  975-5747
fax: (306) 975-5143
URL:  http://gwrp.cciw.ca/nhri/nhrc.html