title: Aquatic hazard assessment of a commercial sample of naphthenic acids.
abstract: This paper presents chemical composition and aquatic toxicity characteristics of a commercial sample of naphthenic acids (NAs). Naphthenic acids are derived from the refining of petroleum middle distillates and can contribute to refinery effluent toxicity. NAs are also present in oil sands process-affected water (OSPW), but differences in the NAs compositions from these sources precludes using a common aquatic toxicity dataset to represent the aquatic hazards of NAs from both origins. Our chemical characterization of a commercial sample of NAs showed it to contain in order of abundance, 1-ring>2-ring>acyclic>3-ring acids (∼84%). Also present were monoaromatic acids (7%) and non-acids (9%, polyaromatic hydrocarbons and sulfur heterocyclic compounds). While the acyclic acids were only the third most abundant group, the five most abundant individual compounds were identified as C(10-14) n-acids (n-decanoic acid to n-tetradecanoic acid). Aquatic toxicity testing of fish (Pimephales promelas), invertebrate (Daphnia magna), algae (Pseudokirchneriella subcapitata), and bacteria (Vibrio fischeri) showed P. promelas to be the most sensitive species with 96-h LL50=9.0 mg L(-1) (LC50=5.6 mg L(-1)). Acute EL50 values for the other species ranged 24-46 mg L(-1) (EC50 values ranged 20-30 mg L(-1)). Biomimetic extraction via solid-phase-microextraction (BE-SPME) suggested a nonpolar narcosis mode of toxic action for D. magna, P. subcapitata, and V. fischeri. The BE analysis under-predicted fish toxicity, which indicates that a specific mode of action, besides narcosis, may be a factor for fishes.
authors.affiliation: EcoTox Assessments, 506 Tenant Circle, Saint Michaels, MD 21663, USA. Electronic address: jswigert@atlanticbb.net.
authors.forename: James P
authors.initials: JP
authors.lastname: Swigert
authors.affiliation: ExxonMobil Biomedical Sciences, 1545 Route 22 East, Annandale, NJ 08801, USA.
authors.forename: Carol
authors.initials: C
authors.lastname: Lee
authors.affiliation: Shell Health Americas, One Shell Plaza, 910 Louisiana St, Houston, TX 77002, USA.
authors.forename: Diana C L
authors.initials: DC
authors.lastname: Wong
authors.affiliation: American Petroleum Institute, 1220 L Street NW, Washington, DC 20005, USA.
authors.forename: Russell
authors.initials: R
authors.lastname: White
authors.affiliation: Biogeochemistry Research Centre, Plymouth University, Drake Circus, Plymouth PL4 8AA, UK.
authors.forename: Alan G
authors.initials: AG
authors.lastname: Scarlett
authors.affiliation: Biogeochemistry Research Centre, Plymouth University, Drake Circus, Plymouth PL4 8AA, UK.
authors.forename: Charles E
authors.initials: CE
authors.lastname: West
authors.affiliation: Biogeochemistry Research Centre, Plymouth University, Drake Circus, Plymouth PL4 8AA, UK.
authors.forename: Steven J
authors.initials: SJ
authors.lastname: Rowland
mesh_terms: D048908:Aliivibrio fischeri / Q000187:drug effects*; D000818:Animals; D002264:Carboxylic Acids / Q000633:toxicity*; D000460:Chlorophyta / Q000187:drug effects*; D003530:Cyprinidae / Q000502:physiology*; D003621:Daphnia / Q000187:drug effects*; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D002264:Carboxylic Acids; D014874:Water Pollutants, Chemical; C046170:naphthenic acid
keywords: Aquatic toxicity; Biomimetic extraction; GC×GC–MS; Naphthenic acids