Thanks, to all of those who commented on our GC-IRMS question a few
weeks back.  To help solve the problem (as suggested by several
groups) we replaced our Valco 4-way valve (we were actually using a
3-way) with a smaller SGE valve (VSLNU/005 UNION part# 1236300).
This is a zero dead volume glass lined union, which we are used the
normal SGE two hole ferrules to make a "3-way" union for the He
backflush.  So far this set-up seems better, and our backgrounds have
come down.

-Bill Anderson











--
William Anderson
Assistant Professor
Geology Department and Southeast Environmental Research Center
Florida International University

Mailing address:
Geology Dept., PC 344
FIU
11200 S.W. 8th Street
Miami, FL  33199
USA

office: 305 348 2693, sec. 348 3572
SERC stable isotope lab:  305 348 3044
fax: 305  348 3877
email: [log in to unmask]