Urchin-like Co3O4 microspheres-boosted catalytic oxidation: Environmentally-friendly CO2 vapor generation for total organic carbon detection by microplasma optical emission spectrometry

Abstract

Total organic carbon (TOC) is a crucial indicator of organic pollutants, widely used in environmental water quality monitoring and risk assessment. Conventional TOC detection methods often require high temperatures, complex equipment, and inefficient oxidation processes, limiting their field application due to time consumption, intricate operations, and limited sensitivity. Therefore, we developed a novel approach for TOC measurement using catalytic oxidation vapor generation coupled with miniaturized point discharge optical emission spectrometry (μPD-OES). This method employs urchin-like Co3O4 microspheres to convert organic pollutants to carbon dioxide during persulfate catalytic oxidation, followed by collection and quantification via carbon atomic emission line (λ = 193.0 nm). Standard or sample solutions were acidified with phosphoric acid and purged with Ar before quantification. Under optimal conditions, the proposed method achieved a detection limit of 0.01 mg L−1, offering precision (RSD, n = 11) better than 3.7 %. The feasibility of the system was tested using a certified reference material (GBW(E)082053) and environmental water samples, achieving satisfactory recoveries (98–102 %). This method provides high oxidation efficiency, sensitivity, and accuracy, while also reducing the demand for expensive and bulky instruments and minimizing energy consumption, making it suitable for rapid, sensitive field analysis of TOC.