All organic compounds are originated from living species composed of carbon skeleton and primarily contain carbon, hydrogen and oxygen. Element(s) other than these if present are termed as hetero atom(s). Among several hetero atoms, a few atoms like Nitrogen, Sulphur, Halogens (Chlorine, Bromine, Iodine but not fluorine), Phosphorous, etc. can be identified by chemical reactions. These elements are described as foreign elements. The qualitative detection of either the presence or absence of special elements acts as a diagnostic tool for characterization of a compound.