Color Reaction of 2 (2 Imidazolylazo) 5 diethylamino Phenol with Vanadium and Its Application in Spectrophotometry

Color reaction of 2 (2 imidazolylazo) 5 diethylamino phenol(IZAPN) with vanadium are studied in this paper In the presence of HAc NaAc (pH 5 0) IZAPN reacts with V(Ⅴ) to form a stable red complex ( n V(Ⅴ) ∶ n R=1∶2) The maximum absorption is at 575 nm with apparent molar absorptivity of 2 96×10 4 L·mol -1 ·cm -1 Beer′s law is obeyed in the concentration range of 0～0 8 mg/L for vanadium(Ⅴ) The selectivity of the reaction is improved by the addition of NaF and thiourea as masking agents The method has been applied to the determination of vanadium in aluminum alloys and synthetic waste water samples The recovery of standard addition is 100 0%～100 5% with precision of ≤2 0% RSD( n =6)