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why bubble appear in Teflon tubing
Posted: Tue Jun 22, 2010 8:26 pm
by jiang295
why bubble would appear in Teflon tubing between solvent bottle and pump head? what cause this? my flow rate is 18ml/min. is this flow rate too high for frit?
Thanks a lot if you can help.
Posted: Tue Jun 22, 2010 8:39 pm
by tom jupille
The short answer: teflon is permeable to air. That's one of the advantages of the in-line degassers: they are located immediately adjacent to the pump inlet, so there is little opportunity for air to diffuse back in.
Re: why bubble appear in Teflon tubing
Posted: Tue Jun 22, 2010 9:13 pm
by JGK
why bubble would appear in Teflon tubing between solvent bottle and pump head? what cause this? my flow rate is 18ml/min. is this flow rate too high for frit?
Thanks a lot if you can help.
18 mL/Minute, what kind of chromatography are you doing
Re: why bubble appear in Teflon tubing
Posted: Tue Jun 22, 2010 9:26 pm
by jiang295
prep scale.
why bubble would appear in Teflon tubing between solvent bottle and pump head? what cause this? my flow rate is 18ml/min. is this flow rate too high for frit?
Thanks a lot if you can help.
18 mL/Minute, what kind of chromatography are you doing
Posted: Tue Jun 22, 2010 9:29 pm
by jiang295
thanks. I also used inline degasser. but it is for analytical usage.
and I do not think there is prep scale degasser as I saw in other thread.
The short answer: teflon is permeable to air. That's one of the advantages of the in-line degassers: they are located immediately adjacent to the pump inlet, so there is little opportunity for air to diffuse back in.
Posted: Wed Jun 23, 2010 8:09 am
by HW Mueller
Just remove the frit and see whether you still get bubbles.
Posted: Wed Jun 23, 2010 3:31 pm
by tom jupille
If the bubbles are really causing problems, use a bubble trap located just upstream of the pump inlet.
Posted: Wed Jun 23, 2010 4:03 pm
by jiang295
thanks .
Just remove the frit and see whether you still get bubbles.
Posted: Wed Jun 23, 2010 4:03 pm
by jiang295
thanks.
If the bubbles are really causing problems, use a bubble trap located just upstream of the pump inlet.
Posted: Wed Jun 23, 2010 8:05 pm
by danko
Jiang295,
There are two reasons for seeing the bubbles in the Teflon tubings.
1. These are the only transparent components in the flow path allowing visibility of what’s in them (apart from the reservoirs if transparent and I bet you can see air bubbles in them too).
2. Teflon is quite hydrophobic and air “feelsâ€
Posted: Fri Jun 25, 2010 6:08 pm
by jiang295
hi danko,
I did use vacuum plus ultrasonic to degass our sample.
[quote="danko"]Jiang295,
There are two reasons for seeing the bubbles in the Teflon tubings.
1. These are the only transparent components in the flow path allowing visibility of what’s in them (apart from the reservoirs if transparent and I bet you can see air bubbles in them too).
2. Teflon is quite hydrophobic and air “feelsâ€
Posted: Fri Jun 25, 2010 10:12 pm
by danko
hi danko,
I did use vacuum plus ultrasonic to degass our sample.
And now you might like to degass the mobile phase as well.
Best Regards