College Of Basic Education Research Journal

Abstract

A simple and fast spectrophotometric method has been developed for determination of resorcinol based on the oxidative coupling reaction with terephthalic acid and in the presence of coppric sulfate as an oxidizing agent in basic medium from NaOH to form a colored product. The maximum absorption of the resulting complex at the wavelength was 440 nm, and the molar absorbance was 7486 l.mol^-1. cm^-1 for concentrations that followed Beer's law in the range of 0.4-18 μg. ml^-1, The detection limit value was 0.55 μg. ml^-1 and the quantitative limit was 1.82 μg. ml^-1. and the accuracy of the method was 98.55%, while the relative standard deviation was less than 2.5% for the studied compound. It was found that resorcinol is formed with terephthalic acid in a ratio of 1:1, and the stability ratio of the formed complex was 4.844×10⁵ (l.mol^-1), which indicates the good stability of the product.