Sequestration of a fluorinated analog of 2,4-dichlorophenol and metabolic products by L. minor as evidenced by 19F NMR

Abstract

Fate of halogenated phenols in plants was investigated using nuclear magnetic resonance (NMR) to identify and quantify contaminants and their metabolites. Metabolites of 4-chloro-2-fluorophenol (4-Cl-2-FP), as well as the parent compound, were detected in acetonitrile extracts using 19F NMR after various exposure periods. Several fluorinated metabolites with chemical shifts ∼3.5 ppm from the parent compound were present in plant extracts. Metabolites isolated in extracts were tentatively identified as fluorinated-chlorophenol conjugates through examination of signal-splitting patterns and relative chemical shifts. Signal intensity was used to quantify contaminant and metabolite accumulation within plant tissues. The quantity of 4-Cl-2-F metabolites increased with time and mass balance closures of 90–110% were achieved. In addition, solid phase 19F NMR was used to identify 4-Cl-2-FP which was chemically bound to plant material. This work used 19F NMR for developing a time series description of contaminant accumulation and transformation in aquatic plant systems.