J J Singh
Articles written in Proceedings – Section A
Volume 56 Issue 5 November 1962 pp 269-273
Lanthanum, gadolinium and yttrium are quantitatively precipitated by diammonium-5, 5′-indigo disulphonate between pH 3·0 and 7·5 and the resulting complexes on ignition give the corresponding oxide which can be weighed. Quantities as little as 4·75 mg. of La2O3, 3·3 mg. of Gd2O3 and 4·2 mg. of Yt2O3 can be thus determined.
Volume 60 Issue 2 August 1964 pp 85-89
4-Hydroxy-3-methoxy benzaldehyde (vanillin) precipitates titanium quantitatively between pH 3·5 and 6·5. The precipitate on ignition gives TiO2 which can be weighed. Titanium can be readily separated and estimated gravimetrically in the presence of chromium (III), cobalt (II), copper (II), iron (III), manganese (II), molybdenum (VI), nickel (II), tungsten (VI), uranium (VI), vanadium (V), zinc (II), zirconium (IV), and trivalent rareearths.
Volume 64 Issue 3 September 1966 pp 182-184
Vanillin, quantitatively precipitates zirconium between pH 5·0–6·5, as insoluble complex. This complex on ignition gives ZrO2 which can be weighed. Zirconium can be readily separated and determined in the presence of varying quantities of chromium (III), cobalt (II), copper (II), manganese (II), molybdenum (VI), nickel (II), titanium (IV), tungsten (VI), uranium (VI), vanadium (V), zinc (II) and trivalent rare earths.