Open AccessFlotation-Spectrophotometric Determination of Vanadium with 3,5-Dinitrocatechol and Rhodamine B
Author(s) -
Ryszard Łobiński,
Zygmunt Marczenko
Publication year - 1988
Publication title -
analytical sciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.392
H-Index - 73
eISSN - 1348-2246
pISSN - 0910-6340
DOI - 10.2116/analsci.4.629
Subject(s) - vanadium , chemistry , molar absorptivity , oxalate , extraction (chemistry) , acetone , metal , rhodamine b , cyclohexane , detection limit , metal ions in aqueous solution , inorganic chemistry , lanthanum , chelation , nuclear chemistry , spectrophotometry , chromatography , organic chemistry , physics , photocatalysis , optics , catalysis
International audienceA new method of flotation separation and preconcentration of vanadium traces is described. The ion-associate formed by the anionic vanadium(V)-3, 5-dinitrocatechol complex and Rhodamine B is floated with cyclohexane. The separated and washed compound readily dissolves in acetone, giving an intensely coloured solution which forms the basis for a sensitive spectrophotometric determination of vanadium. The molar absorptivity is 2.1x105! mol-1 cm-1 at 555 nm and the detection limit is 3ng/ml. Beer's law is obeyed up to a vanadium concentration of 0.3 jig/ml. The composition of the floated compound was established. Its proposed formula is [(RB)j]-[VO(OH)(DNC)2]. EDTA, oxalate and some metals interfere. The method becomes specific for vanadium after a preliminary extraction of the metal as its N-benzoyl-/V-phenylhydroxylamine (BPHA) chelate from a HCI-HF medium. The method was applied to the vanadium determination (0.2-9 ppm) in some vegetables. © 1988, The Japan Society for Analytical Chemistry. All rights reserved