Improvement in the Iatroscan thin-layer chromatographic-flame ionisation detection analysis of marine lipids. Separation and quantitation of monoacylglycerols and diacylglycerols in standards and natural samples

Mono- and diacylglycerols are important intermediates in glycerolipid biode gradation and intracellular signalling pathways. A method for mass determin ation of these lipid classes in marine particles was developed using the Ia troscan, which combines thin layer chromatography (TLC) and flame ionisatio n detection (FID) techniques. We improved existing protocols by adding two elution steps: hexane-diethyl-ether-formic acid (70:30:0.2, v/v/v) after tr iacylglycerol and free fatty acid scan, and acetone 100% followed by chloro form-acetone-formic acid (99.1:0.2, v/v/v) after 1,2 diacylglycerols. Diacy lglycerol isomers 1,2 and 1,3 were separated from each other, as well as fr om free sterols in standards and marine lipids from sediment trap particles . Monoacylglycerols were separated from pigments and galactosyl-lipids in t he same trap samples and in a rich pigment phytoplankton extract of Dunalie lla viridis. Quantitation of each class in samples was performed after cali bration with 0.5 to 2 mu g of standards. As many as 17 lipid classes can be identified and quantified in samples using this proposed six-step developm ent. (C) 1999 Elsevier Science B.V. All rights reserved.