GC question

[ninja 101]

Can anybody give me a comprehensive list of non polor stationary phases available for gas chromatography?

Also in a exam I was asked to identify a peak after two minutes in a gc chromatogram,it had the higest peak yet was not the major solvent,what could it be?

[GOM]

Hi,

You could try looking here as a start

http://www.chem.agilent.com/cag/cabu/propphase1.htm

As for the second part of your query, some possibilities are,

1. if the major portion was water as a solvent then it would not be detected if you were using a flame ionisation detector (which responds best to organic compounds).
2. Or it could be a compound that has a higher response than the major solvent (in the detector that was being used).
3. The major solvent has such a high boiling point that it doesn't come off under the conditions used.
4. It had the highest peak because it was the sharpest peak but the actual peak area could be lower than the major solvent.
5. An obvious answer that I have missed !

I think that we would really need to see the question in full.

Regards,

Ralph

[chromatographer1]

Here is a small selection without discussing the proprietary bonded phases which each company may synthesize independently like SPB-1 HP-1 Rtx-1 DB-1 etc:

APIEZON H
APIEZON J
APIEZON K
APIEZON L
APIEZON M
APIEZON N
APIEZON T
APIEZON W
APOLANE-C87
DC-200 (100 cstks)
DC-200 (12,500 cstks)
DC-200 (350 cstks)
DC-200 (500 cstks)
DC-410
DC-430
Dexsil 300 carborane/methyl silicone
GE SF-96
HEXADECANE
JXR SILICONE
OV-1
OV-101
SE-30
SE-31
SE-33
SE-52
SE-54
SP-2100
SP-2100 DA
SP-2100 DB
Squalane
Squalene
SYLGARD 184 SILICON ELASTOMER
UCW-982

Now about the mystery peak:

One really needs to see what sample was being injected and the detector being used.

It could be air if it were injected with the liquid sample.

It could be a noise spike.

It could be almost anything. Even someone playing with the chart recorder (for you old-timers out there).

But certainly it has to be something that your detector can detect.

best wishes,

Rod