Determination of Vanadium in Water and Biological Samples Using N-Hydroxy-N-o-Tolyl-N'-(2-Methyl)-Phenyl-Benzamidine Hydrochloride and 4-Hydroxy Benzaldehyde

Abstract

A simple rapid and sensitive method has been developed for the detection
and spectrophotometric determination of vanadium(V) in water samples
and biological samples. N-Hydroxy-N-o-tolyl-N'-2 methyl phenyl
benzamidine hydrochloride reacts with vanadium(V) in presence of 4-
hydroxy-benzaldehyde giving deep green-blue complex which is quantitatively
extractable at pH 2.3 to 5.1. The Sandell's sensitivity of the reaction
is 0.0061  μg/cm^-2 at 580-590 nm, with molar absorptivity 8280 ± 50 L
mole^-1 cm^-1 . Mo(V), Fe(III), Co(II) and Ni(II) etc. do not interfere with
the determination. The limit of identification of the spot test based on this
colour reaction is 0.1 μg of vanadium with dilution limit  1 : 1 x 10⁶.