| Popis: |
Publisher Summary This chapter discusses the acyl lipids in photosynthetic systems. Lipids of photosynthetic bacteria contain only saturated and monounsaturated acids. Qualitative analysis of lipid composition is most commonly carried out by thin-layer chromatography (TLC) on silicic acid. This chapter describes techniques by which a single spot containing 2–3 μg of acyl lipid can be reliably quantitated and smaller amounts can be detected. For quantitation, lipid acyl groups are converted to methyl esters: The silica gel containing the lipid in question is removed from the plate and treated with warm methanolic sulfuric acid to affect transesterification. Heptadecanoic acid is added to serve as a quantitative internal standard and is simultaneously esterified; the combined methyl ester mixture is extracted with hexane and quantitatively analyzed by gas chromatography (GPC). With a nonpolar column, (SE-30) esters of the same carbon number are eluted together. The accuracy of quantitation of a 1-μg lipid spot is approximately 10% of the value determined. |
