Sulphur is a non – metallic chemical element with the symbol ‘S’. It is present in many organic compounds like thiol, carbon disulphide etc. The antibiotics penicillin and the artificial sweetener saccharin etc are also sulphur containing organic compounds. Upon fusion with sodium metal, the sulphur atom in the organic compound is converted to ionic sodium sulphide, which can be extracted by boiling the fused mass with distilled water and is used for the detection of sulphur.
This video explains how to detect the presence of sulphur in an organic compound.