Triacylglycerol position isomer, analysis

Mottram, H.R., Evershed, R.P. (1996) Structure analysis of triacylglycerol positional isomers using atmospheric pressure chemical ionisation mass spectrometry. Tetrahedron Letters, 37,8593-8596. 

Stiibiger and colleagues [36] used a similar approach (in addition to the MS analysis of lipid species subsequent to reelution from the TLC plate) to screen the compositions of various neutral (e.g., triacylglycerols) and polar (e.g., GPL and glyc-erosphingolipids [GSL]) lipid classes derived from crude lipid extracts of human plasma as well as soybean lecithin. These authors [36] have also provided evidence that combining TLC/MS with post source decay (PSD) MALDl MS helps to address structural problems such as the detailed fatty acyl composition and the differentiation of positional isomers sn- vs. sn- I). PSD may be considered an MS/MS-Uke experiment that can be performed on all TOP instruments equipped with a reflectron [20] but without the need of a dedicated collision ceU. About 70 different lipid species could be detected in just 50 jL of human blood plasma. 

Herrera, L.C., Potvin, M.A. and Melanson, J.E. (2010) Quantitative analysis of positional isomers of triacylglycerols via electrospray ionization tandem mass spectrometry of sodi-ated adducts. Rapid Commun. Mass Spectrom. 24, 2745-2752. 

As an aid in the identification of such triacylglycerols in butterfat, Marai et al. (128) have investigated the reversed-phase LC-MS behavior of randomized butterfat, which contains the various isomeric triacylglycerols in known and sufficient amounts for analysis. The results show that conventional C, 8 reversed-phase columns would not resol ve the positional and reverse isomers of mixed acid triacylglycerols, but that the resolution of isologous triacylglycerols is retained also when two or three short-chain fatty acids occur per molecule. 

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