Sensitive determination of hydrogen peroxide in real water samples by high spin peroxo complex

In this paper, a fast, cheap, simple, sensitive and selective spectrophotometric method based on high spin peroxo-Fe(III)-EDTA complex in the alkaline medium was developed for the determination of hydrogen peroxide (H₂O₂) in real water samples. The purple-coloured complex with a maximum absorbance at a wavelength of 525 nm was formed. Various parameters such as type of stabilizer reagent and its concentration, reaction time, Fe(III), EDTA and NH₃ concentration were optimized. The method was confirmed with the Beer's law with a molar absorption coefficient of 267.36 L mol^-1 cm^-1 in the 8.3 ×10^-6 -4.08 ×10^-3 mol/L concentration range. Sandell's sensitivity of the proposed method was also calculated as 0.188 μg/cm² . LOD and LOQ were determined as 2.5 ×10^-6 and 8.3 ×10^-6 mol/L, respectively. Intraday and interday relative standard deviation of the proposed method for 2.0 ×10^-4 mol / L of H₂O₂ were found as 1.5% and 6.1%, respectively. The developed method is suitable for fast monitoring of H₂O₂ in different types of aqueous water samples without any sample preparation steps and acceptable recovery values between 90% and 118% were obtained. In the sample analysis, H₂O₂ removed solutions from the real water samples were used for blank correction in their analysis and this process provides more reliable and accurate results in real sample analysis.