International Journal of Analytical and Applied Chemistry
General and Organic Chemistry Laboratory Experiments for Science , Pre-medical, and Pharmacy studentsChapter IV: Identification and Purification of Organic Compounds
Associate professor, University of Benghazi, Faculty of Science, Department of Chemistry, Libya
Abstract
In order to identify an organic compound, a chemist needs to apply the suitable technique, depending on the compound state. Accordingly, melting point identification is applied for solids, boiling point for liquids, and sublimation for some compounds which have the tendency to sublime. On the other hand, When an organic compound is isolated from its natural source such as plants, it can be contaminated with some other undesirable compounds, called impurities. Therefore, a special technique, called re-crystallization is used to obtain the original compound in a crystalline form. This technique belongs to the purification techniques. This chapter consists of two main parts, the identification and the purification techniques of some important organic compounds. Another techniques is used depending on the solubility of the organic in a special solvent compared to another in which the organic compound is sparingly soluble, depending on compound’s polarity. This technique is called the solvent extraction. The same situation is found with the qualitative technique, the chromatography, which determines the compound’s purity. In this chapter, highlights will be thrown on most of these techniques used to identify and purify some organic compounds, based on the compound’s polarity, solubility, in addition to its physical state and capability to change from a physical state to another.
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