I'm looking for the word-on-the-street these days for the best (including
cost!) septa for water equilibrations using systems like the Finnigan Gas
Bench or Micromass Aquaprep. The standard has been kel-f backed with
silicone, the kel-f to limit CO2 - septa reactions, the silicone for better
resealing. I've also heard of folks using viton, but this worries me for
What about silicone-backed teflon?
I'd appreciate hearing about any experiences with these different types,
for both CO2 (from carbonates and from water) and for H/D from water.
Also any recommendations on places to buy kel-f septa, if anyone actually
manufacturers them besides the mass-spec companies.