ABSTRACT

We need to have good techniques for puriƒcation of organic compounds because when they are synthesized, or extracted from natural materials, they are not always in a pure form. For example, when a chemical reaction is designed to turn A into B, it rarely does so with 100 % e‘- ciency.  e material we obtain may contain by-products, solvents and reagents, and unreacted starting material. Extracting materials from natural sources can give mixtures of bewildering complexity, with large numbers of components. How can we separate and characterize the material that we want?