Chromatography Forum

Hello,

Is it worthwhile to try and use stabilized THF for HPLC? I am interested in using 100% THF with a GPC column and uv detection. The lower the wavelength I use for the analysis the better, I have tried 235 but the baseline was extremely noisey. I'm guessing that the noise comes from the peroxides? This also makes me wonder, perhaps the stabilizer changes the uv cutoff significantly?

If we cannot use stabilized THF, what procedures are used to prevent oxidation of THF? I've read that nitrogen sparging is used, and while I can imagine what this is, I do not know any specifics on the technique. Again, guessing:
THF in sealed bottle with some type of cap & septa
bottle is under slight pressure from an inlet of nitrogen
Is this close? Are there any websites that can point me to specific equipment used for this?

Regards

Even stabilized THF will oxidize, just more slowly. You can buy solvent reservoirs with special caps for sparging with inert gas. Alltech, Upchurch, Valco, Supelco, all sell them. You should always use safety-coated bottles. You will also need a source of 2-5 psi helium for sparging. The basic approach is to bubble He through the solvent until the O2 is swept out, then close the vent valve to maintain a static pressure.