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Teflon tape and HPLCs: is it ok to use?
Posted: Fri Jul 27, 2012 1:41 am
by DoryFish
I wondered what the consensus was with regards to using Teflon tape on HPLCs? Is it an absolute "NO!!!" or do people use it knowing the risks?
I confess to using it on a couple of metal threads that are impossible to tighten enough to prevent leaks without use of the tape. My use is downstream from the pump and I've an in-line filter before the guard column. That still leaves my autosampler at risk. My precautions are to always remove all "old" tape once a connection is undone, only apply to the back half of thread, and to cut tape with scissors.
Am I playing Russian roulette? And if so, how do I otherwise stop leaks at these wretched connections (in-line mixer being the worst)?
Re: Teflon tape and HPLCs: is it ok to use?
Posted: Fri Jul 27, 2012 1:59 am
by DR
In > 20 years, I've never used it on a HPLC. No need, will just increase odds of leaks.
Re: Teflon tape and HPLCs: is it ok to use?
Posted: Fri Jul 27, 2012 2:27 am
by Don_Hilton
A nice soft polymer. Suggests the presence of some small molecule plasticizers. Even with GC systems, which are less likely to extract monomers from the tape, my answer is no.
Re: Teflon tape and HPLCs: is it ok to use?
Posted: Fri Jul 27, 2012 3:01 am
by remesquaddie
It pays to replace screws and ferrules when fittings leak. Attempting to tighten them too much will lead to snapping the screw inside a fitting which will not ever come out.
Teflon tape in an emergency, BUT NOT AT the following points;
coming out of an injector, going into the column, coming out of the column, going into the detector cell. WILL CREATE DEAD VOLUME if you do.
Re: Teflon tape and HPLCs: is it ok to use?
Posted: Fri Jul 27, 2012 2:24 pm
by DR
It pays to replace screws and ferrules when fittings leak. Attempting to tighten them too much will lead to snapping the screw inside a fitting which will not ever come out.
Teflon tape in an emergency, BUT NOT AT the following points;
coming out of an injector, going into the column, coming out of the column, going into the detector cell. WILL CREATE DEAD VOLUME if you do.
I suggest that stocking some extra .020 and/or .010 SS tubing, a cutter, a file and a few spare ferrules is a far better idea than keeping PTFE tape around. Leave the tape to the plumbers.
Re: Teflon tape and HPLCs: is it ok to use?
Posted: Fri Jul 27, 2012 3:11 pm
by KM-USA
Hey, I'm my own home plumber and auto mechanic as well.
PTFE tape is for tapered pipe thread fittings, and for that use only. Use new connectors as suggested above. Also, polymer ferrules like used with ?Fingertight or similar will "flow" better to seal that stainless steel ones if there's a distortion in a ferrule seat.
PTFE tape is for tapered pipe thread fittings, and for that use only. PTFE tape is for tapered pipe thread fittings, and for that use only. PTFE tape is for tapered pipe thread fittings, and for that use only. PTFE tape is for tapered pipe thread fittings, and for that use only. PTFE tape is for tapered pipe thread fittings, and for that use only. PTFE tape is for tapered pipe thread fittings, and for that use only. PTFE tape is for tapered pipe thread fittings, and for that use only.