Hi Paul,

I agree with Ben on the standards. We have zinc and silver sulfides and 
barium sulfates spanning the range of primary reference materials (-30s to 
+ 20s) and this works out great. We also use vanadium pentoxide as a 
combustion aid for all samples...although I have yet to thoroughly 
investigate when its necessary and when it isn't. You might try contacting 
Craig Cook at SIRFER...he has run feathers and may have some specific 
insights. Also, we keep our dilution ON (conflo III) until right before 
the SO2 peak comes off in an effort to keep the CO2 interference minimal. 
Each of our analyses are exceptionally long as we try to allow the 
background to eek its way as close as possible to something reasonable 
between each peak. Good luck.

andy

Andrew Schauer
Earth and Space Sciences
University of Washington
Seattle, WA 98195

206.543.6327
[log in to unmask]
http://depts.washington.edu/isolab/

On Mon, 26 Apr 2010, stableisotopes wrote:

> Everyone,
> 
> I am setting up the lab to use a new Isoprime and Elementar Isotope Cube
> for total sulfur analysis initially in bird feathers.  After looking
> over the Isogeochem archives it would appear that:
> 
> 1) A normal grade of SO2 as a reference gas should work an high purity gas
> is not necessary.
> 2) All regulators and connections should be stainless steel or a
> compatible SO2 plastics, no brass.
> 3) The pressure of SO2 should be kept less than 1 atm (15psi) coming out
> of the regulator to help avoid condensation of SO2 in the gas supply lines.
> 
> Is this correct and any other words of wisdom?
> 
> Thanks in advance, Paul Brooks.
> 
> 
> -- 
> Mr. Paul D. Brooks,
> Dept. Integrative Biology MC3140,
> 3060 Valley Life Sciences Building,
> UC Berkeley, 94720-3140.
> 
> [log in to unmask]
> 
> phone (510)643-1748
> FAX   (510)643-1749
> 
> http://ib.berkeley.edu/groups/biogeochemistry/
> 
>