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Membrane Water Treatment Volume 14, Number 4, July 2023 , pages 181-189 DOI: https://doi.org/10.12989/mwt.2023.14.4.181 |
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 open accessOptimization of disposable paper-based test strips for hypochlorous acid detection |
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Rita E. Ampiaw, Muhammad Yaqub, Changyeon Woo and Wontae Lee
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| Abstract | ||
| The Covid-19 pandemic has increased demand for chlorine-based sanitizing solutions, most of which contain hypochlorous acid (HOCl) as an active agent. Free chlorine (HOCl) in these sanitizers is crucial for their efficacy. Disposable test strips are affordable and convenient tools for determining various qualitative and quantitative parameters. In this study, disposable opto-chemical test strips were developed by physically immobilizing 3,3',5,5'-tetramethylbenzidine (TMB) and o-dianisidine (o-D) reagents on chromatography and filter paper-based test strips for the visualization and detection of free chlorine in the form of HOCl. The reagents undergo a rapid color change upon reaction with chlorine through a redox reaction. The paper-based test strips showed rapid color change within a minute and a low sample volume requirement (1 ml). This portable, disposable paper-based test strip is a simple and cost-effective way to rapidly detect the presence of HOCl sanitizers for home and field applications. Both TMB and o-D successfully detected chlorine. Chromatography paper proved to be the more efficient option among the two papers used as substrates for the reagents (TMB and o-D). It exhibited high retention capacity and high performance in terms of color transformation when reacting with HOCl, even after two months of storage. | ||
| Key Words | ||
| chromogenic reagents; chlorine; disinfectant; hypochlorous acid; paper test strip; sanitizer | ||
| Address | ||
| Rita E. Ampiaw, Muhammad Yaqub, Changyeon Woo and Wontae Lee: Department of Environmental Engineering, Kumoh National Institute of Technology, 61, Daehak–ro, Gumi 39177, Republic of Korea | ||
