2018/03/20 by David H. Gonzalez, Xiaobi M. Kuang, John A. Scott +3
Earth and Planetary Sciences · Environmental Science · #Advanced oxidation water treatment #Air Quality and Health Impacts #Atmospheric chemistry and aerosols
paper · doi:10.1080/00032719.2018.1431246
crossref issued 2018/03/20 · crossref published 2018/03/20 · crossref published-online 2018/03/20 · openalex publication_date 2018/03/20 · crossref created 2018/03/20 · crossref published-print 2018/10/13 · crossref deposited 2020/08/16 · openalex created_date 2025/10/10 · crossref indexed 2026/07/29 · openalex updated_date 2026/07/30
Hydroxyl radicals (.OH) are key players in chemistry in surface waters, clouds, and aerosols. Additionally, .OH may contribute to the inflammation underlying adverse health outcomes associated with particulate matter exposure. Terephthalate is a particularly sensitive probe for hydroxyl radicals, with a detection limit as low as 2 nM. However, there is uncertainty in .OH quantification using this method, and potential for interferences from some transition metals. Terephthalate reacts with .OH to form a fluorescent product, 2-hydroxyterephthalic acid (hTA), with a moderate dependence on pH and temperature. However, there is disagreement in the literature on the yield of the fluorescent product (YhTA), which introduces a large uncertainty in the quantification of OH. Additionally, TA and similar organic probes are known to complex Cu(II) at high concentrations; thus, if this reaction is important at lower concentrations, Cu(II) could reduce apparent hTA formation, and reduce activity of Cu(II) in target samples. Using a pH 3.5 dark ferrous Fenton system to generate .OH radicals, we find that YhTA = 31.5 ± 7%. This is about double the recent literature value measured, but in excellent agreement with earlier measurements. Additionally, we find that interactions between Cu(II) and hTA are small enough to be ignored at Cu(II) concentrations below ∼50 µM.