Development of Method and Protocol to Track Fluoride Formation During Defluorination of Compounds Found in Pharmaceuticals and Pesticides
The use of fluorinated compounds in pharmaceuticals and pesticides is becoming increasingly common due to their ability to modify the chemical properties of the molecules. A wide range of fluorinated molecules have been detected in surface waters and groundwater storages, the compounds originating from sources such as direct application, water runoff from agricultural lands, and wastewater and industry discharge. It has been found that fluorinated molecules, specifically pesticides, can form persistent byproducts which can be resistant to biological degradation processes. Previous research has analyzed how photochemistry affects both fluorinated and non-fluoridated compounds, usually utilizing a light source (whether natural or simulated) that included a range of light wavelengths. Formation of fluoride (defluorination of the compound) is desirable upon degradation. A new method using a UV-Vis spectrophotometer to track the formation and quantification of fluoride was developed to determine the best way to track the defluorination reactions. This method was used to track fluoride during nucleophilic attack degradation reactions for several fluorinated pesticides and pharmaceuticals. The compounds were also subjected to five different UV wavelengths to determine the specific wavelengths that are suitable for defluorination under photolysis. High-pressure liquid chromatography allowed for identification and quantification of parent compounds. This method can be utilized to analyze how fluorinated chemicals (both old and newly created) transform in different environmental conditions, helping understand how these compounds degrade and form new structures. Future research on the defluorination of common compounds will assist in more effective treatment methods.