Ro. Adlof, ANALYSIS OF FATTY-ACID MONOACYLGLYCEROL AND DIACYLGLYCEROL POSITIONALISOMERS BY SILVER ION HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY, Journal of chromatography, 741(1), 1996, pp. 135-138
Citations number
20
Categorie Soggetti
Chemistry Analytical","Biochemical Research Methods
Mono- and diacylglycerol positional isomer pairs were separated (as ac
etates) by silver ion high-performance liquid chromatography on a comm
ercially available column using an isocratic solvent system of 1.2% (v
/v) acetonitrile in hexane and flame ionization detection. The acetate
derivative(s) from the 1- and 2-monoacylglycerols and 1,2- and 1,3-di
acylglycerols were prepared by acetic anhydride-pyridine. Conversion o
f the thermodynamically less stable 2-mono- and 1,2- diacylglycerols t
o triacylglycerols containing acetate(s) in the 1-, 3- and 2-positions
, respectively, resulted in <3% isomerization. Conversion of the therm
odynamically more stable 1-mono- and 1,3-diacylglycerol analogues yiel
ded <1% isomers. Less than 0.5% inter-esterification by-products were
noted. The triacylglycerol, the diacylglycerol-monoacetate isomer pair
, the monoacylglycerol-diacetate isomer pair and triacetin were comple
tely separated for the 16:0 and 18:1 fatty acid series. The triacylgly
cerols eluted first and the triacetin eluted last. The 16:0 elution pa
ttern is unusual, since silver ion chromatographic separations are gen
erally ascribed to the interaction of silver ions with carbon-carbon d
ouble bond pi-electrons, a condition absent in the 16:0 series.