Effect of pH on the Spectral Properties of Acid Orange Seven and Plasmocorinth B Dyes in Aqueous Systems

Abstract

The present study investigated the effect of pH on the spectral properties of Acid Orange 7 and Plasmocorinth B azo dyes in aqueous systems. Several concentrations of each dye were prepared from a stock solution. The molar extinction coefficient (Ô‘) and maximum absorption wavelength  of the dyes in different pH environments were measured using a UV/Vis spectroscopy. Dye absorbance was measured between λ=200 nm-800 nm. The results indicate that the maximum absorption wavelengths of AO7 and PC-B were determined at 485 nm and 528 nm respectively. The molar extinction coefficient (Ô‘) was calculated at Acid Orange 7= 20647 dm³. Mol^-1.cm^-1 and Plasmocorinth B= 19203 dm³.mol^-1.cm^-1. The finding shows that pH has no effect on the absorbance of the aqueous dye solutions indicating dye stability under different pH levels.