Plant waxes column chromatography

Cleanup A practical term used to describe the handling of a sample before the measuring step. For example, after the pesticides are extracted from a vegetable, the extract may contain fats and plant waxes that will interfere with the determination of the pesticides. These fats and waxes are removed by solid phase extraction, column chromatography, or gel permeation chromatography, and the extract then is said to be cleaned up,... 

In the examination of plant waxes various analytical methods have been used, including ultraviolet and infrared spectroscopy, and thin-layer, column, and gas-liquid chromatographies (Eglinton and Hamilton, 1967). The infrared spectrum has been used to indicate hydroxy compounds, ketones, ethers, and lactones, as well as the more common esters and hydrocarbons. In the use of thin-layer or column chromatography, infrared spectra can be used to make sure that there is no carryover of one class of components into another. 

Figure 6.12 Chromatography and mass spectrometry of plant waxes. (1) Thin-layer chromatogram of broccoli leaf wax and gas-liquid chromatogram of the hydrocarbon fraction isolated from this wax. (2) Partial gas-liquid chromatogram of the alkane fraction from the surface lipids of tobacco leaves. (3) Partial gas-liquid chromatograms of the hydrocarbons from N. muscorum illustrating resolution of 8- (a), 7- (b) and 6- (c) monomethyl heptadecanes on a 750ft capillary column. (A)-(C) Partial mass spectra taken at points indicated in (2) illustrating identification of n- and branched alkanes. Reproduced with permission from Kolattukudy (1980).

Thin-layer chromatography (tic) or column chromatography on silica gel is the most widely used technique for separating plant waxes into fractions of... 

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