Toti:

We have just completed our 40,000th dual-inlet analysis with a GVI 
Optima-MultiPrep combination, nearly all on CO2 evolved from 
phosphoric acid digestion of carbonates, over 9 years.  We have 
noticed absolutely no reaction between CO2 and the PEEK tubing used 
between the double needle and water trap of our MultiPrep, nor is CO2 
adsorbed onto the PEEK tubing.

Since all of the gases generated by combustion of organic samples are 
carried by stainless steel or silica capillaries in our 
continuous-flow set-up, I can't comment on PEEK tubing and other 
gases like N2 or SO2.

Hope this helps.

Steve


>Folks,
>
>Has any one replaced stainless steel tubing with PEEK tubing to 
>carry He+ sample gas to either a Multiflow or Gasbench? Has anyone 
>noticed any reaction with PEEK tubing and different gases?
>Right now I have a stretch of PEEK tubing supplying Helium to the 
>flush end of a two-holed needle and 1/16th inch stainless steel 
>tubing to carry Helium + sample gas (either CO2 or N2O in my case) 
>to a GV multiflow/Tracegas. There is no SO2, H2S, H3PO4 involved in 
>this method. I'm more comfortable with stainless steel, but maybe 
>PEEK tubing is inert to CO2 and N2O?
>
>Thanks
>Toti.

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