Spectrophotometric determination of Vanadium using new analytical reagent 7-(6-bromo-2-benzothiazolylazo)-8- hydroxyquinoline

Abstract

A new thiazolylazo reagent, 7-(6-bromo-2-benzothiazolylazo)-8-
hydroxyquinoline (7-(6-BrBTA8HQ)), was synthesized by di azo coupling of (2-
amino-6-bromobenzothiazol derivative) with 8-hydroxy quinoline, and used for the
spectrophotometric determination of vanadium (V). This method was simple, rapid,
sensitive, and selective for reaction between vanadium and 7-(6-BrBTA8HQ) to form
a dark orange complex with a molar ratio (1:2).The molar absorptivity of the complex
was (1.9737*103L. mol_.cm_) at λ max 634 nm. Beer's law obeyed in the range of (1-
14)ppm of vanadium,and the stability constant was equal to (0.1088*1010 L2. Mol2-).
The relative standard deviation,recovery, and relative error were equal to
(0.631%,98%,2%) respectively. The ions ( Cr2+ ,Mn2+ , Cu2+ ,Cd2+ ,Fe2+ ,Ni2+ ,Co2+
,Hg2+ ) were interferences when the reagent react with vanadium ,and can be
eliminated approximately using suitable masking agent.
Keywords: 7-(6-bromo-2-benzothiazolylazo)-8-hydroxy quinoline, vanadium,
spectrophotometry