Photocatalytic hydrogen peroxide (H₂O₂) production has emerged as a promising on-site synthesis strategy for environmental remediation, particularly in Fenton-like reactions. This method eliminates the risks associated with storing and transporting high-concentration H₂O₂ by generating it directly from water and oxygen under light irradiation. Accurate quantification of H₂O₂ is essential to understand reaction mechanisms and optimize system performance. However, the presence of organic electron donors—commonly used to enhance charge separation and H₂O₂ yield—can interfere with standard detection methods. This study evaluates three widely used techniques: potassium permanganate (KMnO₄) titration, ammonium metavanadate (NH₄VO₃) colorimetry, and N,N-diethyl-p-phenylenediamine–horseradish peroxidase (DPD-POD) colorimetry. The interference effects of seven representative organics—ethanol, acetaldehyde, acetic acid, acetone, phenol, p-benzoquinone, and bisphenol A—were systematically assessed across low (50 μM), medium (200 μM), and high (1 mM) H₂O₂ concentrations.

Results indicate that KMnO₄ titration is highly susceptible to aromatic compounds due to their direct oxidation by KMnO₄, leading to significant overestimation even at 0.1 mM. For instance, p-benzoquinone induced a relative error of 873% at this concentration. Aliphatic organics like ethanol and acetaldehyde also caused notable interference, though less severe than aromatics. In contrast, NH₄VO₃ colorimetry showed greater resistance to aliphatic interferents, with maximum errors below 11%. However, p-benzoquinone significantly affected this method due to its strong electron-accepting ability (ELUMO = −2.64 eV), promoting unwanted reduction pathways and distorting results, especially at higher concentrations (>1 mM). The DPD-POD method demonstrated excellent selectivity against aliphatic organics but failed in the presence of p-benzoquinone, which reacted directly with DPD to form a pink-colored quinone imine, mimicking H₂O₂ signal. Moreover, phenolic intermediates such as hydroquinone caused immediate decolorization of DPD⁺, resulting in severe underestimation.

A mechanistic analysis based on HOMO-LUMO energy gaps (Egap) revealed that lower Egap values correlate with higher reactivity toward oxidants, explaining the differential interference patterns. Based on these findings, a decision flowchart was developed to guide method selection depending on the nature and concentration of coexisting organics.CD46 Antibody Biological Activity For systems without organics, all methods are viable within their respective detection ranges.Cyclin D1 Antibody custom synthesis When aliphatic organics dominate, DPD-POD is preferred for low- and medium-concentration H₂O₂.PMID:33797312 For aromatic compounds, especially when p-benzoquinone or phenols are present, caution is required; NH₄VO₃ may be acceptable only at low p-benzoquinone levels (<1 mM), while DPD-POD should be avoided entirely. In complex matrices, multiple methods or non-redox-based alternatives such as ion chromatography with UV detection are recommended for validation. This work provides critical insights for reliable H₂O₂ monitoring in photocatalytic and Fenton-like systems, supporting accurate optimization and mechanistic understanding.MedChemExpress (MCE) offers a wide range of high-quality research chemicals and biochemicals (novel life-science reagents, reference compounds and natural compounds) for scientific use. We have professionally experienced and friendly staff to meet your needs. We are a competent and trustworthy partner for your research and scientific projects.Related websites: https://www.medchemexpress.com