In the pharmaceutical world, an impurity is considered as any other organic material, besides the drug substance, or ingredients, arise out of synthesis or unwanted chemicals that remains with API‟s. Variousregulatory authorities like ICH, USFDA, Canadian Drug and Health Agency are emphasizing on the purity requirements and the identification of impurities in Active Pharmaceutical Ingredient‟s (API‟s). The control ofpharmaceutical impurities is currently a critical issue to the pharmaceutical industry. The impurity may be developed either during formulation, or upon aging of both API‟s and formulated API‟s in medicines. The presence of these unwanted chemicals, even in small amount, may influence the efficacy and safety of the pharmaceutical products. Any material that affects the purity of the material of interest viz. active ingredient or drug substance. The impurities are not necessarily always inferior. From the standpoint of its usage, the drug substance is compromised in terms of purity even if it contains another material with superior pharmacological or toxicological properties. Highly sophisticated instrumentation, such as mass spectra meters attached to a Gas Chromatography or HPLC, are inevitable tools in the identification of minor components (drugs, impurities, degradation products, metabolites) in various matrices.