Extraction-spectrophotometric determination of cadmium in micro quantities with diphenylcarbazone

Department of Chemistry, Gauhati University, Guwahati-781 014, India E-mail : himadri_gu@yahoo.co.uk Fax: 91-361-570133 Manuscript received 12 April 2000. revised 8 September 2000, accepted 22 December 2000 A simple and sensitive extractive spectrophotometric method for determination of cadmium is described. In presence of pyridine, cadmium forms a red coloured complex with diphenylcarbazone which is extractable in benzene. The extracted species has an absorption maximum at 533 nm and obeys Beer's law for 0.228-3.65 ppm of Cd, the molar absorptivity being 7.33 x 104 dm3 mol-1 cm- 1. Conditions for colour development and interferences from foreign ions have been studied