Plant extracts migration

The plant extract samples can be applied directly onto the plate, or a specific class of compounds is extracted in a suitable solvent before TLC. The polarity of the solvent used for extraction should be similar to that of the desired compounds. The samples can be applied onto the plates manually, by using calibrated micropipettes or automated applicators. The applied samples can be spots or bands, and the mobile-phase migration distances vary between 8 and 15 cm. 

These can be the natural material itself one example would be pieces of vanilla pod or an extract, e.g. vanilla extract. Extracts can be prepared in several ways. One is to distil or to steam distil the material of interest. Another is to extract the raw material with a solvent, e.g. ethyl alcohol. Alternatively, some materials are extracted by coating the leaves of a plant with cocoa butter and allowing the material of interest to migrate into the cocoa butter. These techniques are also used in preparing perfumery ingredients, indeed materials like orange oil are used in both flavours and perfumes. 

Heavy metals in the environment, especially their accumulation in soils, is a serious environmental problem which the whole world faces (Du et al. 2005). The farmland soils are an important media of the ecological cycle of Cadmium, and its harm to human health can t be neglected (Wu et al. 2004). Heavy metal migration, transformation and toxicity to plants in soil are directly influenced by the quantity proportions of various forms (Zhu et al. 2002). The toxicity of water-extractable and adsorbed and exchangeable metals are the greatest, and residual metals is the lowest (Liu etal. 2002). Different forms have different bioavailability thus their influences on the environment and human health are different. It is critical to have a good understanding of Cadmium forms in soil. This paper describes the Cadmium forms in the acid soils of eastern China. 

The object of chemical extraction is to separate the psychoactive alkaloids from the plant material. This is done by first simmering the crushed plant in an acidified water bath, which converts the alkaloids into their salt form. After filtration, the plant pulp may be discarded. To extract the alkaloids from the water, the remaining liquid is made basic and an organic solvent is added. The alkaloids will migrate into this solvent, which can then be drawn off and poured into a shallow dish.The solvent will quickly evaporate, leaving behind the alkaloids in pure crystalline form (you should be so lucky ), or more commonly, as a relatively impure gummy compound. 

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