Synthesis of the new 2-[6-Nitro-2-benzothiazolylazo]-4-bromo phenol organic reagent for spectrophotometric determination of Zinc(II).

Abstract

      A new  2-[6-Nitro-2-benzothiazolylazo]-4-bromo phenol (NO₂BTABrP) organic reagent was synthesized. A sensitive and selective spectrophotometric method was proposed for the rapid determination of Zn(II)  using (NO₂BTABrP) reagent .The reaction between Zn(II) and (NO₂BTABrP) reagent is instantaneous at pH=6.0 and                                                                    the absorbance  remains stable for over 24 hrs.

   The Method allows for the determination of  Zn(II) over the range (0.3-4.0) µg.ml^-1 ,with molar absorptivity of (6.221 x 10⁺³)l.mol ^‑1.cm^-1 and a detection limit of 0.147 µg.ml^-1.Recovery and relative error values of precision and accuracy of method were found to be  R.S.D=1.6% , Re=98.84% , and Erel =-1.16% . The properties of complex was studied and show;(M:R) ratio was 1:2 at pH=6.0 ,and the stability constant of 8.23 x 10⁺⁹ l².mol^-2 . The interferences of  ions  (Cu²⁺ , CrO^2- , Ca²⁺ , pb²⁺  , Co²⁺ , Mg²⁺  , Cd²⁺, Ba²⁺ , Bi³⁺) and masking agents effect on absorbance were studied .