Differential-pulse polarographic determination of molybdenum in steel

Abstract

A method for the determination of molybdenum in steel, based on catalytic electroreduction by the molybdate ion, is described. After a suitable sample dissolution, iron is removed by cation exchange and molybdenum is eluted with 0.5 M nitric acid. The eluate is diluted 1 + 1 with 4 M ammonium nitrate solution, and polarographic analysis carried out over the range from 0 to –1.0 V versus a saturated calomel electrode. The method is applicable to the determination of molybdenum in the 0.001–5% of molybdenum range and good agreement is reported for a number of certified British Chemical Standard and commercial steels.