Gravimetric Determination of Vanadium As V(IV)-Oxinate
Chem. Anal. (Warsaw), 38, 639 (1993) Gravimetric Determination of Vanadium as V(IV)-Oxinate by S. Kaur, A. K. Chhakkarand L. R. Kakkar* Department ofChemistry, Kurukshetra University, Kurukshetra -132119, Haryana; India Key words: vanadium(V), oxine, 8-hydroxyquinoline, gravimetry A very simple gravimetric method for the determination of vanadium has been worked out. In acid medium vanadium is reduced to tetravalent state which forms greenish-black precipitate with 8-hydroxyquinoline (2 % in 2 mol 1-1 CH3COOH) in the presence of ammonium acetate. The precipitate is dried and weighedas VO(C9H60 N)2. The con version factor for vanadium is 0.1437. The method is free from the interference of molybdenum(VI), chromium(III,VI), uranium(VI), selenium(IV), arsenic(I1I), bis muth(III), lead(U), calcium(II), manganese(I1) and maguesium(II). Opracowanoprosta wagow'\ metode oznaczania wanadu. Wauad(V) redukuje silt w kwasnym roztworze do wanadu(IV), ktory w obecnosci octanuamonu tworzy z 8-hydro ksychinolina (2 % roztwor w 2 mol 1-1CH3COOH) zielonoczaruy osad. Po wysuszeniu osad jestwazonyjako VO(C9H60 Nh Mnoznik analityczny wynosi dla wanadu 0,1437. W oznaczeniu nie przeszkadzaja: molibden(VI), chrom(III,VI), uran(VI), selen(IV), arsen(III), bizmut(III), o16w(II), wapriffl), mangan(II} i magnez(II), Many inorganic [1-4a] and organic [5-8, 11] precipitants employed for the estimation of vanadium in milligram amounts are. unsuitable for routine analysis, either because they are not quantitative or because other elements are coprecipitated withvanadium, and also in some cases, the precipitate formed does not have a definite composition. Cup ferron [4b] is generally recommended for the precipitation of vanadium, but several precautions are necessary because ofthe instability of cupfer ron and many other elements are precipitated by the reagent under conditions ofthe * Senior author for correspondence.
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