Chromatography Forum

i want to separate 2 methyl butyric acid & 3 methyl butyric acid on CPG :
Zb wax, azot, split, FID. Which parameters can i change? At 60°C to 220°C it is not possible.
Thank you to help me.

A method via derivatization is described in
http://pmr.cuni.cz/Data/files/PragueMed ... C3%A1k.pdf

On a packed column seperation is described in
http://www.sigmaaldrich.com/Graphics/Su ... 0/7150.pdf


My proposal is:

Column: Carbowax 20M, 30mx0.25x0.25
- 40°C/2 min. as a start (cold trapping of your components which gives narrow initial bands. This is also far too conversative)
- 2°C/min to 120°C (I know this ramp is too slow; just try and check if you see a separation).



Now please tell us what method parameters you're using:
- Sample transfer (split, splitless, ...)
- Solvent
- Carrier gas and column head pressure
- Column (Diameter, phase, film thickness, ...)
- Temperature program

Did you try my suggestions?