Chromatography Forum

Hello everybody,

i have an mixture of gases of HFPO , HFP .
i analysed it on GC with capillary column Connected with FID and got some separation. but i am not able to separate the HFPO and HFP base to base on my Capillary column . i used four typese of capillary column and one packed column with TCD.
i also tried it on 120Mtr column for separation but not get proper separation.
can anybody help me regarding selection of a suitable capillary column which is able to separate base to base HFPO AND HFP.

CHANDRESH

Not knowing what you have tried, and since VERY few folks analyze HFP and HFPO, I can only reply in theory that a very polar column with strong acidic or alcoholic functional groups might theoretically work.

FFAP (SP-1000) and silica gel columns come to mind. A molecular size separation (Porapak P) might also work.

Good luck,

Rod

Thanks Rod,

I Have DBFFAP with nitroterapthalaic acid modified phase , and i can try.
chandresh

FFAP with nitroterapthalaic acid modified phase

This is originally called from the inventor: SP-1000

I tried the HFP and HFPO Samples on DB-FFAP Column.
the Details are
Column DB-FFAP , 30Mtr.0.32mm I.D.,0.25µm film thickness.
Oven Programming : 40°C ( 8.0Minute Hold) and Ramp @5°C up to 70°C.
Injector 150°C and Detector 250°C ( FID)
Carrier is Hydrogen and flow is 0.5ml constant flow.
But the separation is not achived . can someone help me about the more parameters or columns for thinking .

chandresh

The molecule is probably too big for the Q polymer, but the P polymer or Chromosorb 103 might be a solution.

The pi electrons on the oxygen are probably very poorly interactive, due to the electronegativity withdrawing of all the fluorines attached to the carbon backbone.

Even the added single atom to the molecule won't give you much separation.

The oxygenates column from Agilent might be a possibility.

best wishes,

Rod

The difference in MW is 16 D - a bit more than a methyl group, so if it is only these two that you need to separate maybe a non-polar, non-selective phase is worth a try. To get the best resolution you need to increase your carrier flow by a factor of four from the 0,5 ml/min that you currently use.

Peter

That is a good suggestion Peter.

Rod