CATALYTIC SPECTROPHOTOMETRIC DETERMINATION OF TRACES OF MOLYBDENUM(VI)

The catalytic effect of molybdenum on the reduction of Nile blue by hydrazine is utilized. The method is based on measuring the decrease in absorbance of Nile blue after the fixed time of 3 min at 595 nm at 25-degrees-C. The interferences of various ions were studied and a cation-exchange resin column was used to remove interfering ions. Five replicate analyses of a sample containing 3-mu-g.ml-1 of molybdenum had a relative standard deviation of 0.67%. The method enables rapid and reliable analysis of molybdenum over the concentration range of 40-3000 ng.ml-1 in different samples.