@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 = {

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 \< 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 (\>0.5) than those of NEtFOSA, NEtFOSAA, and NEtFOSE (\<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.

}, 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} } @article {114, title = {Derivatization method for sensitive determination of fluorotelomer alcohols in sediment by liquid chromatography-electrospray tandem mass spectrometry.}, journal = {J Chromatogr A}, volume = {1288}, year = {2013}, month = {2013 May 03}, pages = {48-53}, abstract = {

Fluorotelomer alcohols (FTOHs) are the main precursors of environmentally ubiquitous perfluorinated acids, and determination of FTOHs at low concentrations presents significant challenges. In this study, a new liquid chromatography-electrospray mass spectrometry (LC-ESI-MS) method in conjunction with low-energy collision dissociation tandem mass spectrometry (CID-MS/MS) was developed by employing an optimized derivatization reaction with dansyl chloride (DNS) in acetonitrile under catalysis of 4-(dimethylamino)-pyridine (DMAP). The instrument detection limits (IDLs) of the newly developed method were 0.014, 0.015, 0.014, 0.0075 and 0.0093μg/L for 4:2 FTOH, 6:2 FTOH, 8:2 FTOH, 10:1 FTOH and 10:2 FTOH respectively, which were 7.5-241 times lower than those without derivatizaiton and 57-357 times lower than previous GC/MS method. The method was successfully applied to analyze FTOHs in sediments combined with WAX and silica cartridges cleanup. The overall method recoveries were from 67{\textpm}6.0\% to 83{\textpm}9.4\% with matrix effects of \<15\%. The limits of quantification for all FTOHs were 0.017-0.060ng/gdry weight (dw). The method was applied to analyze six marine sediment samples from Liaodong Bay, China. All FTOHs except for 10:1 FTOH were detected, and the total concentrations of FTOHs were 0.19-0.52ng/gdw. The developed method provides a new method to sensitively determine FTOHs in environmental matrices.

}, keywords = {Alcohols, China, Chromatography, High Pressure Liquid, Environmental Pollutants, Fluorocarbons, Geologic Sediments, Reproducibility of Results, Sensitivity and Specificity, Spectrometry, Mass, Electrospray Ionization, Tandem Mass Spectrometry}, issn = {1873-3778}, doi = {10.1016/j.chroma.2013.02.085}, author = {Peng, Hui and Hu, Kejun and Zhao, Fanrong and Hu, Jianying} } @article {118, title = {Determination and occurrence of retinoic acids and their 4-oxo metabolites in Liaodong Bay, China, and its adjacent rivers.}, journal = {Environ Toxicol Chem}, volume = {29}, year = {2010}, month = {2010 Nov}, pages = {2491-7}, abstract = {

Retinoic acids (RAs) and their metabolites play an important role in abnormal morphological development and are speculated to be a possible cause for the increased rates of deformities in wild frog populations. In the current study, a method using ultra-performance liquid chromatography-electrospray ionization tandem mass spectrometry was developed for simultaneously analyzing all-trans-RA (at-RA), 13-cis-RA (13c-RA), 9-cis-RA (9c-RA), and their 4-oxo metabolites, all-trans-4-oxo-RA (at-4-oxo-RA), 13-cis-4-oxo-RA (13c-4-oxo-RA), and 9-cis-4-oxo-RA (9c-4-oxo-RA) in wastewaters and surface waters. Method detection limits were matrix dependent, ranging from 0.02 to 0.37 ng/L. The method was used to investigate the occurrence of RAs and 4-oxo-RAs in Liaodong Bay and its adjacent rivers. Of these six retinoids, at-RA, 13c-RA, at-4-oxo-RA, and 13c-4-oxo-RA were detected in river waters at detection frequencies of 100\%, 92\%, 48.6\%, and 21.6\%, and concentrations of 0.05 to 1.23 ng/L, less than 0.03 to 0.41 ng/L, less than 0.02 to 1.00 ng/L, and less than 0.06 to 0.81 ng/L, respectively. Retinoic acids were detected for the first time in the aquatic environment and were found to be more persistent than 4-oxo-RAs. The hazard quotient for mortality of frog embryos caused by induction by retinoids detected in the current study was then estimated, and the value was calculated to be 0.09. No retinoid was detected in seawaters.

}, keywords = {China, Chromatography, High Pressure Liquid, Rivers, Spectrometry, Mass, Electrospray Ionization, Stereoisomerism, Tretinoin, Water Pollutants, Chemical}, issn = {1552-8618}, doi = {10.1002/etc.322}, author = {Wu, Xiaoqin and Hu, Jianying and Jia, Ai and Peng, Hui and Wu, Shimin and Dong, Zhaomin} }