title: Identification of petrogenic produced water components as acetylcholine esterase inhibitors.
abstract: Effect-directed analysis (EDA) was applied to identify acetylcholine esterase (AChE) inhibitors in produced water. Common produced water components from oil production activities, such as polycyclic aromatic hydrocarbons (PAHs), alkylphenols, and naphthenic acids were tested for AChE inhibition using a simple mixture of PAHs and naphthenic acids. Produced water samples collected from two offshore platforms in the Norwegian sector of the North Sea were extracted by solid phase extraction and fractionated by open-column liquid solid chromatography and high-performance liquid chromatography (HPLC) before being tested using a high-throughput and automated AChE assay. The HPLC fractions causing the strongest AChE inhibition were analysed by gas chromatography coupled to a high-resolution time-of-flight mass spectrometry (GC-HR-ToF-MS). Butylated hydroxytoluene and 4-phenyl-1,2-dihydronaphthalene were identified as two produced water components capable of inhibiting AChE at low concentrations. In order to assess the potential presence of such compounds discharged into aquatic ecosystems, AChE activity in fish tissues was measured. Saithe (Pollachius virens) caught near two offshore platforms showed lower enzymatic activity than those collected from a reference location. Target analysis of saithe did not detected the presence of these two putative AChE inhibitors and suggest that additional compounds such as PAHs, naphthenic acids and yet un-identified compounds may also contribute to the purported AChE inhibition observed in saithe.
authors.affiliation: Norwegian Institute for Water Research (NIVA), Gaustadalléen 21, N-0349 Oslo, Norway; Department of Chemistry, University of Oslo (UiO), PO Box 1033, Blindern, N-0316 Oslo, Norway. Electronic address: jfr@niva.no.
authors.forename: Jean
authors.initials: J
authors.lastname: Froment
authors.affiliation: Norwegian Institute for Water Research (NIVA), Gaustadalléen 21, N-0349 Oslo, Norway.
authors.forename: Katherine
authors.initials: K
authors.lastname: Langford
authors.affiliation: Norwegian Institute for Water Research (NIVA), Gaustadalléen 21, N-0349 Oslo, Norway.
authors.forename: Knut Erik
authors.initials: KE
authors.lastname: Tollefsen
authors.affiliation: Norwegian Institute for Water Research (NIVA), Gaustadalléen 21, N-0349 Oslo, Norway.
authors.forename: Inger Lise N
authors.initials: ILN
authors.lastname: Bråte
authors.affiliation: Norwegian Institute for Water Research (NIVA), Gaustadalléen 21, N-0349 Oslo, Norway.
authors.forename: Steven J
authors.initials: SJ
authors.lastname: Brooks
authors.affiliation: Norwegian Institute for Water Research (NIVA), Gaustadalléen 21, N-0349 Oslo, Norway.
authors.forename: Kevin V
authors.initials: KV
authors.lastname: Thomas
mesh_terms: D000110:Acetylcholinesterase / Q000032:analysis* / Q000378:metabolism; D000818:Animals; D002800:Cholinesterase Inhibitors / Q000032:analysis* / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D029941:Fish Proteins / Q000032:analysis* / Q000378:metabolism; D005399:Fishes / Q000378:metabolism; D008401:Gas Chromatography-Mass Spectrometry; D009659:North Sea; D011084:Polycyclic Aromatic Hydrocarbons / Q000032:analysis / Q000378:metabolism; D012623:Seawater / Q000737:chemistry*; D052616:Solid Phase Extraction; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000378:metabolism
chemical_list: D002800:Cholinesterase Inhibitors; D029941:Fish Proteins; D011084:Polycyclic Aromatic Hydrocarbons; D014874:Water Pollutants, Chemical; D000110:Acetylcholinesterase
keywords: Acetylcholine esterase inhibitors; Effect-directed analysis; Produced water