title: p-Sulphobenzeneazo-4-(2,3-dihydroxy-5-chloropyridine) as a reagent for spectrophotometric determination of niobium(V).
abstract: Niobium reacts with p-sulphobenzeneazo-4-(2,3-dihydroxy-5-chloropyridine) to form an orange-red ML(2) complex having maximum absorbance at 485 nm in citric acid medium at pH 6.0 +/- 0.5. The reaction is slow at room temperature, but complete in 10 min at 60 degrees . The colour is stable for at least 16 hr. The system obeys Beer's law over the concentration range 0.5-8 mu/ml. The molar absorptivity is 5.26 x 10(3)l.mole(-1).cm(-1).
authors.affiliation: Department of Chemistry, Ganjdundwara College, Ganjdundwara, 207242, India.
authors.forename: Y
authors.initials: Y
authors.lastname: Sharma