Hi Mario,

I found the abstract (see below) which might help - in brief, they
used ODS column and Acetonitrile/Water mobile phase with
differential refractometer and the MAGs were underivatized.

Also, there were a few posts to the chrom-L mailing list in
which HPLC methods for FAMEs (fatty acid methyl esters)
were discussed.

http://groups.yahoo.com/group/chrom-l/messages
Search for long-chain fatty acids and message 221 and 228
have the most details.

Obviously this method would involve you having to transmethylate
your MAGs and use a rather unconventional method but I suppose
it has the advantage that standards (FAMEs) are well characterised
and easy to get hold of.

Larodan (http://www.larodan.se) sell a range of saturated
and unsaturated monoacylglycerols so they might help in the
development of a method, although I think they purify theirs with TLC.

Jo

SEPARATION OF MONOACYLGLYCEROLS BY
REVERSED-PHASE HIGH-PERFORMANCE
LIQUID-CHROMATOGRAPHY

SEMPORE BG, BEZARD JA
JOURNAL OF CHROMATOGRAPHY
596 (2): 185-195 APR 10 1992

Abstract:
Reversed-phase high-performance liquid chromatography on a
thermostated octadecylsilyl column was used, to separate complex
mixtures of monoacylglycerols formed by chemical deacylation of
natural oil triacylglycerols. Acetonitrile water mixtures were used
for elution of the underivatized monoacylglycerols and a differential
refractometer was used for their detection. The order of elution
of monoacylglycerols in complex mixtures varies as a function of
the chain length, unsaturation, positional isomerism, analysis
temperature and eluent water concentration. The peak areas were
representative of the amounts of monoacylglycerols detected.
The method can be applied to compositional analysis and to the
collection of non-contaminated fractions for further stereospecific
analysis.