LAUSR

Abstract Chromium (VI) is an identified carcinogen and mutagen, and hence, it is necessary to determine its concentration in environmental and biological samples. A technique specified for the colorimetric determination of Cr(VI) in water and soil samples. This method premised on an oxidative coupling reaction of 3- Aminophenol (3AP) with 4-Aminoantipyrine (4-AAP) as a chromogen in the presence of peroxidase mimetic Fe2O3 nanoparticles (IONPs) as a catalyst. The reaction mixture forms a red-colour complex that shows a maximum absorbance at 490 nm. The IONPs synthesized by precipitation method, succeeded by characterization with X-ray diffraction (XRD), Fourier transform infrared spectrophotometer (FTIR), Scanning electron microscopy (SEM), and energy-dispersive spectrophotometer (EDX). The Beer’s law obeyed from 0.02 μg mL−1 to 0.8 μg mL−1, and the molar absorptivity is 2.575 × 104 Lmol−1 cm−1. The Limits of quantification and Limit of detection of the proposed method are 0.003 μg mL−1 and 0.0009 μg mL−1 sequentially. The results had statistically evaluated with that of the published method for the water and soil analysis.