Extractive Differential Pulse Polarography of Mo (VI) Oxinate in Chloroform and its Application in the Determination of Molybdenum in Steel

The voltammetric characteristics of Mo (VI) oxinate at the mercury electrode, in the presence of tri-butylammonium perchlorate (tri-BAP) and piperidinium perchlorate (PP) + piperidine (P) as  two different types supporting electrolytes, have been studied in chloroform. With the both supporting electrolytes a two electron irreversible process for the reduction  of Mo (VI) oxinate was observed. Preceded by a solvent extraction of Mo (VI) oxinate in chloroform, the DP method was used for the determination of molybdenum. In the presence of 0.2 M tri-BAP as supporting electrolyte, the calibration graph was linear over the range 0.5 to 50 mM. and the detection limit was 0.16 mM about 10 times lower than the case of PP + P. The proposed  method using Mo (VI) oxinate-tri-BAP system has been successfully applied for the  determination of molybdenum in steel.