Testing with 100% THF

[ndtrung0807]

My lab have 3 supplier HPLC, Agilent 1200, 1260; Water UPLC and Water 2690 HPLC and Shimadzu. Next month, my lab intended to run method with 100% THF. But i don't know which machine can run 100% THF?
Please give me some advice!
Thank you
Tom

[DR]

First, ask why you need to run 100% THF...

Provided the answer makes any sense at all, go with the system that has no PEEK tubing in it.

[Vlad Orlovsky]

also make sure that your column has no PEEK parts inside (for example our columns have PEEK seals inside, so we limit THF to 10%).

[ndtrung0807]

Dear DR and Vlad Orlovsky
Thank for reply
please tell me why we should use column no PEEK, How THF influence column? my lab usually use Column C18 and method from R&D center said my lab to run with 100% THF

[HPLCaddict]

100% THF can dissolve PEEK.
100% THF is about the strongest eluent you can use in RP on C18. It's reaaaaaaally strong. If you really need such a strong eluent to elute your analytes, I'd rather switch to a different column chemistry which shows weaker interaction with your analytes so you can use weaker eluents than 100% THF.

[tom jupille]

Actually, PEEK doesn't dissolve in THF, it gets brittle:
http://www.sepscience.com/Techniques/LC ... -Follow-up

THF has other disadvantages as well (storage stability, UV cutoff) so that it's not generally a first choice. That said, if its a case of having to redevelop a method versus finding a PEEK-free system, I'd be tempted to go the PEEK-free route.

[DR]

In addition to causing brittleness, it can cause swelling which means occlusion prior to breakage and leakage. THF is also super viscous, so if you use it straight, plan on super high pressures and low flow rates.

All in all, it's no fun to use... especially when the safety people hear about it and introduce you to the peroxide test strips. You probably can't use the stabilized THF because the stabilizers have some hefty chromophores that will interfere w/ UV detection. The unstabilized stuff needs to be nitrogen blanketed or it will create its own interfering degradants.

So, aside from breaking your tubing, being a PITA to work with, being unstable and peroxide forming and eating anything you spill it on (that contains any plasticizers at all)... it's fine - if you can abide the smell

[Jiri Urban]

In research lab I used 100% THF for (inverse) size-exclusion chromatography of polymers to characterize porous properties of prepared columns. To avoid any instrumental damage I flushed system with isopropanol daily. As already mentioned, THF is not for long-term usage.

In industrial lab, I would probably avoid THF completely.

[ndtrung0807]

thank you everybody
Now, my knowledge is improve much.
i think that i don't have other choice, if my method tell me run 100% THF, what should you recommend me?

Thank you for your help
Thank you for your knowledge
Tom

[tom jupille]

It's impossible to tell from a distance which (if any) of your systems have PEEK tubing because at least some of the tubing has probably been replaced in the course of use and preventive maintenance. You will have to examine each one.

[ndtrung0807]

Thank for reply
Few day ago, I found information about THF and I see, THF is "dangerous" chemical.it can be transfer to "peoxide" easily. Boild temp peroxide ~ THF, so it make a "bomb".if we use KI solution drops 1-3ml THF and identify brown color when peroxide was transfed.

[DR]

There are peroxide test strips that are available. Just pour out a couple of mL, dip the end of the test strip in and see what color it becomes. We do this on a quarterly basis for all unstabilized THF bottles (once opened). We also nitrogen blanket them on use.

[Klaus I.]

Running a HPLC with 100 % THF is not very common.

I strongly recommend that you to have detailed discussions with experienced service engineers of every single system you have considered.

Beside of the mentioned problem with PEEK-capillaries, all components of the HPLC system may be concerned. It is starting with die low-pressure lines (e. g. TEFZEL?), the piston seals and ends at the concrete design of the flow-cell (what seals are there used)?

Best regards
Klaus

P.S.: Don’t underestimate the building of peroxides in ‘stabilized’ THF when the bottle is open