Keywords: UV-Vis spectrophotometer; iron (III); Alizarin Red S; optical sensor

Abstract

Metal ions such as iro(III) ion (Fe3+) have an impact on human health and also play an important function in biological systems. However, the negative effects of Fe3+ ion to human and environment motivate the researchers to find a simple and quick method for Fe3+ detection. The aim of this study is to develop a simple method for determination of Fe3+ ion using Alizarin Red S (ARS) reagent. The reaction between ARS and Fe3+ ion has produced ARS-Fe(III) blackish-brown complex. All the optimization studies were carried out using UV-Vis Spectrophotometer at 572 nm. A dynamic linear range in acetate buffer solution was obtained in the range of 0.02 - 0.25 M with R2 value of 0.9909. Moreover, stability study indicated that ARS showed stable response for about 7 hours while the reproducibility study was found to give a satisfactory relative standard deviation (RSD) value of 1.63 % and 0.85 %. Based on the interference study, Al3+ and Ca2+ were found to not significantly interfere in the detection of Fe3+ ion while Cu2+ showed some interference. This proposed method is deemed simple and could be a promising method for a rapid and direct detection of Fe3+ ion in both qualitative and quantitative approaches.