Karve M A, Khopkar S M
Department of Chemistry, Indian Institute of Technology, Bombay 400 076, India.
Talanta. 1993 Jun;40(6):913-7. doi: 10.1016/0039-9140(93)80051-r.
A novel method is proposed for the solvent extraction of niobium(V). A 0.1M solution of Aliquat 336S in xylene quantitatively extracts microgram quantities of niobium(V) from 0.01M ascorbic acid at pH 3.5-6.5. Niobium from the organic phase is stripped with 0.5M nitric acid and determined spectrophotometrically in the aqueous phase as its complex with TAR. The method permits separation of niobium not only from tantalum(V) but also from vanadium(IV), titanium(IV), zirconium(IV), thorium(IV), chromium(III), molybdenum(VI), uranium(VI), iron(III), etc. Niobium from stainless steel was determined with a precision of 0.42%.
提出了一种溶剂萃取铌（V）的新方法。0.1M Aliquat 336S的二甲苯溶液在pH 3.5 - 6.5条件下，能从0.01M抗坏血酸溶液中定量萃取微克级的铌（V）。有机相中的铌用0.5M硝酸反萃取，并在水相中以其与TAR的络合物形式进行分光光度法测定。该方法不仅能使铌与钽（V）分离，还能与钒（IV）、钛（IV）、锆（IV）、钍（IV）、铬（III）、钼（VI）、铀（VI）、铁（III）等分离。测定不锈钢中的铌时，精密度为0.42%。
