It is a little surealistic to google a problem, and find that I asked the very same question in this forum in 2006...

Anyhow, I have a problem with oxidation when using the Oasis SPE products. The results are very clear, when using the Oasis WCX cartidges I get up to 100% oxidation of my peptide.

When I changed to a silicabased SPE cartridge (Strata WCX) I see no oxidation at all. Waters says that there are no oxidising substances in the Oasis material, but that is obviously not true.

Anyone else that has seen this phenomenon?