Subject: gas chromatography of fish oil FAMEs

From: [email-masked] (Shankar Bhattacharyya)
Date: 14 Dec 1996 20:29:28 -0500

Has anyone here done a good deal of gas chromatography on fatty acid
methyl esters from fish oils? I have been doing some recently and am a
little confused. While I track down Ackman's papers I would appreciate
any advice I can get.

I'm working with a packed column, 6 ft long, 2 mm id, 10% DEGS. 2 min
at 145 C, 2 deg/min to 200 C, a long time at 200, nitrogen at about
25 ml/min.

I am particularly interested in how they run on packed columns, with
appreciably less resolution than capillary columns provide.
Nutritional labeling work in the US is typically done on packed
columns (often 10% or so DEGS), specifically so that you don't
separate out all of the positional isomers. I am fairly certain that I
am failing to resolve compounds that differ by more than that. Hell,
it's obvious that that's the case.

I have reasonable explanations for some of what I see but there are
still ambiguities. I'm particularly interested in any information on
well-known failures of resolution in these moderately complex mixtures.

Eicosapentanoate and erucate, perhaps? That's a drastic problem.

- Shankar