title: Spectrophotometric determination of niobium and its application to niobium-stabilized stainless steel.
abstract: A spectrophotometric method is described for the determination of niobium by means of its reaction with tannin and thioglycollic acid. The yellow-orange colour developed with the reagent mixture at pH 4 is measured at 410-420 nm and obeys Beer's law between 0.5 and 10 ppm niobium. The method is suitable for the determination of niobium in niobium-stabilized stainless steel and other types of steels containing niobium, but a prior separation of niobium is necessary. Titanium interferes even in traces.
authors.affiliation: Research & Control Laboratory Durgapur Steel Plant Durgapur-3, West Bengal, India.
authors.forename: R K
authors.initials: RK
authors.lastname: Dutta
authors.forename: S
authors.initials: S
authors.lastname: Banerjee