Chromatography Forum

I am using agilent 6890 GC-FID and I make analysis of fatty acid compositions of vegetable oils (mostly sun flower oil). Column is 100 m long and good enough to show even cis-trans separation.
This device shows me good chromatograms but I can't understand which fatty is that. I can only know palmitic, stearic, oleic and linoleic acid's exact retention times .
So, the question is that how can I learn locations (retention times) of different fatty acids? for example C14:0 C20:0 or C:22:0.
I dont have any standart fame mixture and I couldnot make it bought.
Are there any calculation about it?

...
I dont have any standart fame mixture and I couldnot make it bought.
Are there any calculation about it?

You need a standard FAME mix (the one with 37 FAMEs is probably the most versatile).

The best way is to inject each compound individually. Barring that, if you can find a factory chromatogram using your conditions you can find them that way.

The best way is to inject each compound individually. ...

But the price of each individual standard is almost as high as the price of 37 component FAME mix.

Obtain a bar of soap that contains tallowate and either cocoate or palm kernelate. Make fatty acid methyl esters from that.

You'll get observable 8, 10, 12, 14, 16, 18, oleic, and linoleic peaks, plus some smaller ones.