Catalytic-Spectrophotometric Determination of Molybdenum in Plant and Steel with Nile Red-Hydrazine Dihydrochloride Reaction

Abstract

Molybdenum was determined by its catalytic effect on the reduction of nile red with hydrazine dihydrochloride. The method was based on measuring the decrease in absorbance of nile red after 3 minutes at 595 nm at 30° C. The calibration curve was linear over the range of 50 – 30000 ng.ml⁻¹. The detection limit was 30 ng.ml-¹ of Mo(VI). A cation exchanger resin was used to remove interfering ions. Plant materials and steel were used for the determination of molybdenum content. The relative standard deviation was 0.8% for 250 ng.ml-¹ of Mo(VI). Molybdenum could be determined in the presence of even high concentration of phosphate and tung sten.

Key Words:

• Molybdenum
• Nile Red-Hydrazine
• Catalysis
• Plant Material
• Steel