why bubble appear in Teflon tubing

[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.

[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.

[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

[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

[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.

[HW Mueller]

Just remove the frit and see whether you still get bubbles.

[tom jupille]

If the bubbles are really causing problems, use a bubble trap located just upstream of the pump inlet.

[jiang295]

thanks .

Just remove the frit and see whether you still get bubbles.

[jiang295]

thanks.

If the bubbles are really causing problems, use a bubble trap located just upstream of the pump inlet.

[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€

[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€

[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