Chromatography Forum

I have been asked to determine the molar mass of a unpure compound with GCFID. Is this possible? I will run n-Nonane as standard (pure compound) but how can I use this to determine the molar mass of C9+ when it will have multiple compounds in it? Im stuck between a rock and a hard place on this one...so I would appreciate your help.

I very much doubt that it is possible. If you knew what class of chemical it was you could run a series of standards of the same class and see which two of them bracketed the unknown's retention on a methyl silicone phase, but that only gets you from guesswork to informed guesswork.

Peter

Thanks for your reply. The only way I can think of doing it is DHA (detailed hydrocarbon analysis)