@article {108,
	title = {Isomer-specific trophic transfer of perfluorocarboxylic acids in the marine food web of Liaodong Bay, North China.},
	journal = {Environ Sci Technol},
	volume = {49},
	year = {2015},
	month = {2015 Feb 03},
	pages = {1453-61},
	abstract = {<p>Trophic transfers of perfluorocarboxylic acids (PFCAs) have been well studied in aquatic food webs; however, most studies examined PFCAs as single compounds without differentiating isomers. In this study, an in-port derivatization GC-MS method was used to determine PFCA (perfluorooctanoic acid, PFOA; perfluorononanoic acid, PFNA; perfluorodecanoate acid, PFDA; perfluoroundecanoate acid, PFUnDA; perfluorododecanoate acid, PFDoDA; perfluorotridecanoate acid, PFTriDA, and perfluorotetradecanoate acid, PFTeDA) structural isomers in 11 marine species including benthic invertebrates, fishes, and gulls collected in November 2006 from Liaodong Bay in China. The total concentrations of linear PFCAs were 0.35-1.10, 0.93-2.61, and 2.13-2.69 ng/g ww, and the corresponding percentages of branched PFCAs to linear PFCAs were 6.6-15.5\%, 4.2-9.9\%, and 4.5-6.0\% in invertebrates, fishes, and birds, respectively. Except for linear PFOA, significant positive relationships were found between the concentrations of all the target linear PFCAs and trophic levels, and the trophic magnification factors (TMFs) ranged from 1.90 to 4.88. Positive correlations between the concentrations of branched PFCAs isomers and trophic levels were also observed but were without statistical significance. The relatively high biomagnification of linear isomers of PFCAs would lead to low percentages of branched PFCAs to total PFCAs in organisms at high trophic levels. This study for the first time clarified isomer-specific trophic transfers of PFCAs in a marine food web.</p>},
	keywords = {Animals, Bays, Birds, Carboxylic Acids, China, Environmental Monitoring, Fishes, Fluorocarbons, Food Chain, Invertebrates, Isomerism, Water Pollutants, Chemical},
	issn = {1520-5851},
	doi = {10.1021/es504445x},
	author = {Zhang, Zhong and Peng, Hui and Wan, Yi and Hu, Jianying}
}
@article {112,
	title = {Isomer-specific accumulation of perfluorooctanesulfonate from (N-ethyl perfluorooctanesulfonamido)ethanol-based phosphate diester in Japanese Medaka (Oryzias latipes).},
	journal = {Environ Sci Technol},
	volume = {48},
	year = {2014},
	month = {2014 Jan 21},
	pages = {1058-66},
	abstract = {<p>While (N-ethyl perfluorooctanesulfonamido)ethanol (FOSE) -based phosphate diester (diSPAP) has been proposed as a candidate precursor of perfluorooctanesulfonate (PFOS), its potential biotransformation to PFOS has not been verified. Metabolism of diSPAP was investigated in Japanese medaka ( Oryzias latipes ) after exposure in water for 10 days, followed by 10 days of depuration. Branched isomers of diSPAP (B-diSPAP) were preferentially enriched in medaka exposed to diSPAP, with the proportion of branched isomers (BF) ranging from 0.56 to 0.80, which was significantly greater than that in the water to which the medaka were exposed (0.36) (p \&lt; 0.001). This enrichment was due primarily to preferential uptake of B-diSPAP. PFOS together with perfluorooctanesulfonamide (PFOSA), N-ethyl perfluorooctanesulfonamide (NEtFOSA), 2-(perfluorooctanesulfonamido)acetic acid (FOSAA), NEtFOSAA, FOSE, and NEtFOSE were detected in medaka exposed to diSPAP, which indicated the potential for biotransformation of diSPAP to PFOS via multiple intermediates. Due to preferential metabolism of branched isomers, FOSAA and PFOSA exhibited greater BF values (\&gt;0.5) than those of NEtFOSA, NEtFOSAA, and NEtFOSE (\&lt;0.2). Such preferential metabolism of branched isomers along the primary pathway of metabolism and preferential accumulation of B-diSPAP led to enrichment of branched PFOS (B-PFOS) in medaka. Enrichment of B-PFOS was greater for 3-, 4-, and 5-perfluoromethyl PFOS (P3MPFOS, P4MPFOS, and P5MPFOS), for which values of BF were 0.58 {\textpm} 0.07, 0.62 {\textpm} 0.06, and 0.61 {\textpm} 0.05 (day 6), respectively; these values are 5.8-, 7.8-, and 6.4-fold greater than those of technical PFOS. This work provides evidence on the isomer-specific accumulation of PFOS from diSPAP and will be helpful to track indirect sources of PFOS in the future.</p>},
	keywords = {Alkanesulfonic Acids, Animals, Biotransformation, Chromatography, High Pressure Liquid, Environmental Monitoring, Esters, Fluorocarbons, Gas Chromatography-Mass Spectrometry, Half-Life, Hydrocarbons, Fluorinated, Isomerism, Kinetics, Metabolic Networks and Pathways, Organophosphorus Compounds, Oryzias, Phosphates, Reference Standards, Sulfonamides},
	issn = {1520-5851},
	doi = {10.1021/es404867w},
	author = {Peng, Hui and Zhang, Shiyi and Sun, Jianxian and Zhang, Zhong and Giesy, John P and Hu, Jianying}
}
