Spectrophotometric Determination of Zn(II) in Pharmaceutical Formulation Using a New Azo Reagent as Derivative of 2-Naphthol

For the fast investigation of Zn(II) using 2-hydroxy-5-(2-hydroxynaphthalen-1-yl) benzoic acid, a specific novel spectrophotometric technique is suggested in this research. The interaction of the azo reagent with Zn(II) is instantaneous at pH 7, and the absorbance of the solution is stable for more than 24 h. The technique allows zinc levels of 1-18 ppm to be calculated, with a molar absorption of 1.516 x10⁴ l mol^-1 cm^-1. The suggested method for estimating zinc has been widely applied in many pharmaceutical formulations. The error of the determination does not exceed 4%.

Keywords: azo reagent; determination of zinc; spectrophotometry; pharmaceutical preparations

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                                             E-mail: muhaimin.alrufaie@uokufa.edu.iq