title: Occurrence and behavior of the chiral anti-inflammatory drug naproxen in an aquatic environment.
abstract: The present study reports on the occurrence and chiral behavior of the anti-inflammatory drug (S)-naproxen (NAP)-(S)-2-(6-methoxynaphthalen-2-yl)propionic acid-in an aquatic environment under both field and laboratory conditions. In influents and effluents of sewage treatment plants (STPs) in the Tama River basin (Tokyo), (S)-NAP was detected at concentrations of 0.03 µg L(-1) to 0.43 µg L(-1) and 0.01 µg L(-1) to 0.11 µg L(-1), respectively. The concentrations of a major metabolite, 6-O-desmethyl NAP (DM-NAP) were up to 0.47 µg L(-1) and 0.56 µg L(-1) in influents and effluents, respectively. (R)-naproxen was not detected in STP influents, although it was present in effluents, and the enantiomeric faction (= S/[S + R]) of NAP ranged from 0.88 to 0.91. Under laboratory conditions with activated sludge from STPs, rapid degradation of (S)-NAP to DM-NAP and chiral inversion of (S)-NAP to (R)-NAP were observed. During river die-away experiments, degradation and chiral inversion of NAP were extremely slow. In addition, chiral inversion of (S)-NAP to (R)-NAP was not observed during photodegradation experiments. In the river receiving STP discharge, NAP and DM-NAP concentrations reached 0.08 µg L(-1) and 0.16 µg L(-1) , respectively. The enantiomeric faction of NAP in the river ranged from 0.84 to 0.98 and remained almost unchanged with the increasing contribution of rainfall to the river water. These results suggest that the absence and decrease of (R)-NAP in river waters could indicate the inflow of untreated sewage. E
authors.affiliation: Division of Environmental Science, Metropolitan Institute of Public Health, Tokyo, Japan.
authors.forename: Toshinari
authors.initials: T
authors.lastname: Suzuki
authors.forename: Yuki
authors.initials: Y
authors.lastname: Kosugi
authors.forename: Mitsugu
authors.initials: M
authors.lastname: Hosaka
authors.forename: Tetsuji
authors.initials: T
authors.lastname: Nishimura
authors.forename: Dai
authors.initials: D
authors.lastname: Nakae
mesh_terms: D000893:Anti-Inflammatory Agents / Q000032:analysis* / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D004784:Environmental Monitoring; D009288:Naproxen / Q000032:analysis* / Q000378:metabolism; D010782:Photolysis; D045483:Rivers / Q000737:chemistry; D012722:Sewage / Q000737:chemistry; D013237:Stereoisomerism; D053719:Tandem Mass Spectrometry; D014865:Waste Disposal, Fluid; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000378:metabolism
chemical_list: D000893:Anti-Inflammatory Agents; D012722:Sewage; D014874:Water Pollutants, Chemical; D009288:Naproxen
keywords: Chiral inversion; Enantiomeric fraction; Naproxen; Sewage treatment plant