SELECTIVE DETECTION TEST FOR NIOBIUM WITH METHYLTHYMOL BLUE
It was found that at pH 3 to 5 the peroxoniobate moiety (Nb- H/sub 2/O/ sub 2/) gives an intense blue color with Methylthymol Blue. Since Nb- H/sub 2/O/ sub 2/ does not form complexes with diaminocyclohexanetetraacetate (DCYTA), it is possible to secure selectivity in the reaction of Nb-H/sub 2/O/sub 2/ with Methylthymol Blue via the masking action of DCYTA. The rate of color development is slow; a blue color is attained at room temperature within 30 to 40 min, but in boiling solution the reaction is complete after 1 min. The detection limit is 5 mu g and the limit of dilution, 1: 800000. Ta, Ti, Mb, W, Th, and Zr do not interfere. If the amount of Nb present is less than that required to fully complex the amount of dye added, the test color is a red-violet or violet, rather than blue. (P.C.H.)
- Research Organization:
- Metallwerk Plansee A.G., Tirol, Austria
- NSA Number:
- NSA-16-012983
- OSTI ID:
- 4803375
- Journal Information:
- Chemist Analyst, Journal Name: Chemist Analyst Vol. Vol: 51
- Country of Publication:
- Country unknown/Code not available
- Language:
- English
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