Tracking Fluorine during Aqueous Photolysis and Advanced UV Treatment of Fluorinated Phenols and Pharmaceuticals Using a Combined 19F-NMR, Chromatography, and Mass Spectrometry Approach

作者：Akash P. Bhat, Thomas F. Mundhenke, Quinn T. Whiting, Alicia A. Peterson, William C. K. Pomerantz, William A. Arnold · 发表于：ACS Environmental Au · 年份：2022 · DOI：10.1021/acsenvironau.1c00057 · 被引用次数：25 · 研究领域：Fluorine in Organic Chemistry、Inorganic Fluorides and Related Compounds、Per- and polyfluoroalkyl substances research

High Resolution Image Download MS PowerPoint Slide Fluorine incorporation into organic molecules has increased due to desirable changes in the molecular physiochemical properties. Common fluorine motifs include: aliphatic fluorines and −CF 3, or −F containing groups bonded directly onto an aromatic (Ar–CF 3 and Ar–F) or heteroaromatic ring. Photolysis of these compounds, either in natural or engineered systems, is a potential source of new fluorinated byproducts. Given the potential persistence and toxicity of fluorinated byproducts, monitoring of product formation during photolysis of various fluorinated motifs is needed. 19 F-NMR is a means to detect and quantify these species. Ar–CF 3 and Ar–F model compounds (2-, 3-, and 4-(trifluoromethyl)phenol, 2-, 3-, 4-fluorophenol, and 2,6-, 3,5-difluorophenol) were photolyzed under a variety of aqueous conditions: pH 5, pH 7, pH 10, 1 mM H 2 O 2 at pH 7 to form •OH, and 0.5 mM SO 3 2– at pH 10 to form e aq – . Pharmaceuticals with the Ar–CF 3 (fluoxetine) and Ar–F plus pyrazole-CF 3 (sitagliptin) motifs were treated similarly. Parent molecule concentrations were monitored with high pressure liquid chromatography with a UV detector. Fluorine in the parent and product molecules was quantified with 19 F-NMR and complete fluorine mass balances were obtained. High resolution mass spectrometry was used to further explore product identities. The major product for Ar–F compounds was fluoride. The Ar–CF 3 model compounds led to fluoride and...