Biotransformation of the Fluorinated Nonsteroidal Anti-Inflammatory Pharmaceutical Flurbiprofen in Activated Sludge Results in Accumulation of a Recalcitrant Fluorinated Aromatic Metabolite

Flurbiprofen is a fluorinated, nonsteroidal, anti-inflammatory pharmaceutical with potential application in a wide range of maladies. Currently, there is no information regarding its environmental fate. To address this, flurbiprofen is spiked at 500 and 50 ppm into activated sewage sludge taken from the municipal treatment plant of Ankara, Turkey. Flurbiprofen is partially degraded after 80 days, with removal proportion varying from 33% to 48%. Isolation of organisms able to use flurbiprofen as a sole carbon and energy source is unsuccessful. A transient, acid-labile yellow coloration appears in supernatants after addition of flurbiprofen. During disappearance, a novel potential metabolite is detected by high-performance liquid chromatography (HPLC) analyses, a chemical that does not appear in killed controls or in nonflurbiprofen-amended controls. Mass spectra of the novel chemical obtained at low and high collision energies are consistent with 4-(1-carboxyethyl)-2-fluorobenzoic acid, suggesting the application of a canonical metabolic paradigm for halogenated biphenyl metabolism by bacteria in which the nonhalogenated ring is metabolized by dioxygenation and metacleavage, leaving the halogenated aromatic ring behind. This metabolite shows no signs of disappearance after the 80-day monitoring period, implying that the environmental release of flurbiprofen might be of concern.