COLOR REACTIONS OF NIOBIUM IONS WITH CERTAIN REAGENTS CONTAINING o,o'- DIHYDROXYAZO GROUP

Journal Article · Wed Jan 01 04:00:00 EST 1964 · Zh. Analit. Khim.

OSTI ID:4015590

Alimarin, I P; Savvin, S B; Dedkov, Yu M

Bisazo compounds on the basis of chromotropic acid, which are structurally analogous to arsenazo III, and monoazo compounds on the basis of R- salt containing o,o'dihydioxyazo group were studied as reagents for niobium. The most contrasting reactions were observed and the most stable complexes of niobium were formed with the reagents containing -NO/sub 2/, -Cl, -SO/sub 3/H, and other negative groups in meta-positions to the azo group. The interaction goes on in strongly acid (1-6N with respect to HCl) mediums in the presence of tartaric acid and other complexing anlons, and thus good reproducibility, reliability, and selectivity of niobium determination were achieved. An extraction-photometric method was developed based on the extraction of a diphenylguanidinium salt of the corresponding niobium complex and measuring the optical density of the extract. The method permits an essential increase in the selectivity of niobium determination. Sulfates, phosphates, chlorides, tartrates, citrates, and other anions in amounts up to 10-100 mg in 25 ml, Zr (0.2-2 mg in the presence of complexone III), Ti (2-10 mg), Ta (0.10.5 mg), Ca, Al a. o. (5-25 mg) do not irterfere. Fluorides and especially oxalates interfere appreciably. The determinable minimum is 1-2 mu g of Nb in 25 ntl when bisazo derivatives of chromotropic acid are used, and 5-10 mu g of Nb in 25 ml with R-salt derivatives. (auth)

• Research Organization: Vernadskii Inst. of Geochemistry and Analytical Chemistry, Academy of Sciences, Moscow
• NSA Number: NSA-18-019913
• OSTI ID: 4015590
• Journal Information: Zh. Analit. Khim., Journal Name: Zh. Analit. Khim. Vol. Vol: 19
• Country of Publication: Country unknown/Code not available
• Language: Russian

Related Subjects

CHEMISTRY
COLOR
ERRORS
INTERFERING ELEMENTS
NIOBIUM
NIOBIUM COMPLEXES
ORGANIC NITROGEN COMPOUNDS
PHOTOMETRY
QUANTITATIVE ANALYSIS
REACTION KINETICS
SOLVENT EXTRACTION