Chromatography Forum

Hi all,
I'm newbie and I'm trying to find a GC method to analyze SO2 in N2. My concentration of SO2 in N2 balance is from 50 ppm to nearly 2%. For SCD detector, I think this detector is too sensitive with sulfur (it could be overload if SO2 is over 50 ppm). And I also tried to use TCD but it's useless. So if any one has experience in analyzing SO2, please help me. Thanks very much.

Can you split your sample? If you are using a rotary injection valve, just put a smaller loop on it and inject less.

h

SO2 is highly aggresive gas. Make sure you use SufInert deactivated lsample lines, loops, injection port liners. Also consider to use a Siltek deactivated Metal column. I have used MXT 0.53mm with 7 microns for that. On PDMS SO2 will elute very close to COS and for separation, you may have to go subambient.

If No COS is there, teh MXT xcolumn will work.

alternative, you can use a Rt-U-BOND porous polymer. Here SO2 has higher ertention and also gives a good peak shape. Last solution is to use a 0.53mm micropacked Shincarbon in Siltek/sulfnert treated MXT. Here SO2 also elutes as a sharp peak, (but no other sulfur elutes). Very specific and high retention..

detection: FPD, PFPD or SClD.

Injection: use a split, but note that because the SO2 elutes fast, you can make a big error: see also a recent blog on that.
http://blog.restek.com/?p=8610


Jaap de zeeuw, Restek Corporation