A Biochemical GC-MS Application for the Organic Chemistry Laboratory: Determination of Fatty Acid Composition of Arabidopsis thaliana Lipids

A biochemical application of GC-MS in which students determine the qualitative and quantitative lipid composition of plant leaf samples is described. There are four facets of this project: (i) synthesis and characterization of individual fatty acid methyl esters (FAMEs) as standards for GC-MS analysis, (ii) isolation of the fatty acids of Arabidopsis thaliana leaves, both wild type and mutants, as FAMEs, (iii) GC-MS analysis of the Arabidopsis leaf extracts for fatty acid composition, and (iv) comparison of the class results with the literature data for both wild type and the four mutants and with a biochemical model of two pathways for lipid synthesis in Arabidopsis leaves. Because this experimental paradigm links organic synthesis and spectral characterization by IR and NMR, both 1H and 13C, with separation and identification via GC-MS analysis, all of the key areas of laboratory procedure are encompassed in this single project. The experimental design permits a myriad of hypothesis-testing variations. ...