Innowax and Hexane

[Celiagg]

Hello!

Does anayone know if i can inject a mixture of C4,C5,C6 in HEXANe into a stationary phase of plyethileglicol?

Thanks

[chromatographer1]

No problem. Be aware that at temperatures that separate these three analytes the phase will not have liquid characteristics.

That may or may not be a concern for you.

best wishes,

Rod

[Peter Apps]

Hi Celia

You can inject it, but do not expect the components to separate.

Peter

[chromatographer1]

If you wish to separate these three analytes you should use a phase that contains a high percentage of methyl silicone, or you can use a porous polymer column.

With most Wax columns it is very difficult to separate hydrocarbons below C6. You will see some separation of heptane, and excellent separations of octane up through C16. It is an excellent column to separate alkenes in the C8 through C16 range, depending upon temperatures and film thickness used.

However, the best separations of olefins and paraffins in this range are usually found using methyl silicone phases.

best wishes,

Rod

[Celiagg]

Hello everybody!!

Thaks a lot. I alwais learn a lot at this forum..

I'm going to use this mixture to check the system avoiding P&T injection way. I will calculate number of plates of column to know how it is now and to have a "TEST" to be able to prove it other day when i am in problems.

I'm new at CG (just one year) and I did not want to brake the column..

Can anyone tell me a reference book to learn practical gas chromatography? This kind of things, you know: kind of columns , solvents, cares, troubleshooting...all practical and important things of day by day. My detector is a MS 5973N. I'd like to improve its performance, to control the system.

Regards,

[zokitano]

Dear Celia,

regarding books for gas chromatography, you could start with:
Modern Practice of Gas Chromatography by Robert L.Grob.

The practical guide for GC/MS beginners is the book:
Gas Chromatography and Mass Spectrometry a Practical Guide by F.G. Kitson, B.S. Larsen and C.N. McEwen

if you want to learn more about mass spectrometry you should try with books for Mass Spectrometry (for detailed information)

Best regards

[AICMM]

Celiagg,

I have reviewed this and other posts by you and, frankly, you are using the wrong column. You are trying to do volatiles with a wax. Try a DB0624, SPB-624, RTX-VMS or any of the other columns specifically designed for volatiles by purge-and-trap. A 0.2 or a 0.25 id column, thick film (1.4 micron, for example) and 30 or 60 meters is way more suitable to what it sounds like you want to do than a wax. This could solve a LOT of the problems about peak shape, linearity, etc... that you seem to be having.

Best regards.