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Benskin J.P.,AXYS Analytical Services Ltd. | Benskin J.P.,Canadian Department of Fisheries and Oceans | Ikonomou M.G.,Canadian Department of Fisheries and Oceans | Gobas F.A.P.C.,Simon Fraser University | And 3 more authors.
Environmental Science and Technology | Year: 2013

Investigations into the biodegradation potential of perfluorooctane sulfonate (PFOS)-precursor candidates have focused on low molecular weight substances (e.g., N-ethyl perfluorooctane sulfonamido ethanol (EtFOSE)) in wastewater treatment plant sludge. Few data are available on PFOS-precursor biodegradation in other environmental compartments, and nothing is known about the stability of high-molecular-weight perfluorooctane sulfonamide-based substances such as the EtFOSE-based phosphate diester (SAmPAP diester) in any environmental compartment. In the present work, the biodegradation potential of SAmPAP diester and EtFOSE by bacteria in marine sediments was evaluated over 120 days at 4 and 25 C. At both temperatures, EtFOSE was transformed to a suite of products, including N-ethyl perfluorooctane sulfonamidoacetate, perfluorooctane sulfonamidoacetate, N-ethyl perfluorooctane sulfonamide, perfluorooctane sulfonamide, and perfluorooctane sulfonate. Transformation was significantly more rapid at 25 C (t1/2 = 44 ± 3.4 days; error represents standard error of the mean (SEM)) compared to 4 C (t1/2 = 160 ± 17 days), but much longer than previous biodegradation studies involving EtFOSE in sludge (t1/2 ∼0.7-4.2 days). In contrast, SAmPAP diester was highly recalcitrant to microbial degradation, with negligible loss and/or associated product formation observed after 120 days at both temperatures, and an estimated half-life of >380 days at 25 C (estimated using the lower bounds 95% confidence interval of the slope). We hypothesize that the hydrophobicity of SAmPAP diester reduces its bioavailability, thus limiting biotransformation by bacteria in sediments. The lengthy biodegradation half-life of EtFOSE and recalcitrant nature of SAmPAP diester in part explains the elevated concentrations of PFOS-precursors observed in urban marine sediments from Canada, Japan, and the U.S, over a decade after phase-out of their production and commercial application in these countries. © 2013 American Chemical Society.

PubMed | University of Victoria and AXYS Analytical Services Ltd.
Type: Journal Article | Journal: Environmental science & technology | Year: 2016

Sensitive and quantitative protocols for characterizing low-dose effects are needed to meet the demands of 21st century chemical hazard assessment. To test the hypothesis that xenobiotic exposure at environmentally relevant concentrations produces specific biochemical fingerprints in organisms, metabolomic perturbations in zebrafish (Danio rerio) embryo/larvae were measured following 24 h exposures to 13 individual chemicals covering a wide range of contaminant classes. Measured metabolites (208 in total) included amino acids, biogenic amines, fatty acids, bile acids, sugars, and lipids. The 96-120 h post-fertilization developmental stage was the most appropriate model for detecting xenobiotic-induced metabolomic perturbations. Metabolomic fingerprints were largely chemical- and dose-specific and were reproducible in multiple exposures over a 16-month period. Furthermore, chemical-specific responses were detected in the presence of an effluent matrix; importantly, in the absence of morphological response. In addition to improving sensitivity for detecting biological responses to low-level xenobiotic exposures, these data can aid the classification of novel contaminants based on the similarity of metabolomic responses to well-characterized model compounds. This approach is clearly of use for rapid, sensitive, and specific analyses of chemical effect on organisms, and can supplement existing methods, such as the Zebrafish Embryo Toxicity assay (OECD TG236), with molecular-level information.

Woudneh M.B.,AXYS Analytical Services Ltd. | Coreen Hamilton M.,AXYS Analytical Services Ltd. | Benskin J.P.,AXYS Analytical Services Ltd. | Wang G.,AXYS Analytical Services Ltd. | And 2 more authors.
Journal of Chromatography A | Year: 2013

A unique derivatization based method for quantitative analysis of NAs is presented.The method separated saturated fatty acids from NAs while separating NAs into isomer groups.Both intra and inter-laboratory validation data are presented.Data are presented for four types of environmental waters collected from Alberta.Principal component analysis distinguished NA fingerprints in the various samples. A method for quantitative characterization of naphthenic acid (NA) isomer groups by carbon number and extent of cyclization was developed and validated with water samples from northern Alberta. Following solid phase extraction, NAs undergo derivatization with N-(3-dimethylaminopropyl)-. N'-ethylcarbodiimide (EDC) allowing detection by positive electrospray ionization tandem mass spectrometry (+ESI)-MS/MS. NA-EDC derivatives produce a common product ion by MS/MS, regardless of structure of the starting NA. Thus, approximately constant relative response factors (RRFs) were assumed for the various isomer groups that elute at a given point in the elution gradient (supported by calculated RRFs for individual model NAs), facilitating quantification using a single standard (1-pyrenebutyric acid). To reduce the impact of major background fatty acids on NA data, the method employed an optimized liquid chromatography method that separated straight chain (. Z=. 0) analytes from other NAs. Method validation was performed at two spiking levels (7.72. μg and 38.6. μg total refined Merichem per 500. mL of reagent water) and good accuracy (mean recoveries of 82.4. ±. 2.5% and 93.0. ±. 2.6%, respectively; range ~50-130%) and precision (<17% RSD) were achieved at both spiking levels for all 60 NA isomer groups. The method also performed well in an independent method comparison study in which method accuracy values of 107%, 120%, and 121% were obtained for 2 spiked reagent waters (1. mg/L and 50. mg/L NAs) and spiked Athabasca River water (0.035. mg/L NAs), respectively. Application of the method to samples from northern Alberta revealed that NA concentrations decreased in the order: process water (52.8. mg/L). >. tailings pond water (30.6. mg/L). >. well water (0.086. mg/L). >. surface water (0.007. mg/L), and that samples were distinguishable by NA isomer profile using Principal components analysis. © 2013 Elsevier B.V..

Sutton R.,San Francisco Estuary Institute | Sedlak M.D.,San Francisco Estuary Institute | Yee D.,San Francisco Estuary Institute | Davis J.A.,San Francisco Estuary Institute | And 3 more authors.
Environmental Science and Technology | Year: 2015

California has implemented unique consumer product flammability standards. Polybrominated diphenyl ether (PBDE) flame retardants were once widely incorporated into products to meet these standards, but concerns regarding toxicity and accumulation in humans and biota led to nationwide phase-outs and state bans. A decade of PBDE monitoring in San Francisco Bay has resulted in a data set that covers periods during and after PBDE use and consists of hundreds of measurements of water, sediment, and biota. While PBDEs remain widely detected in biota, levels have declined by nearly half in sport fish and 74-95% in bivalves and bird eggs. Concentrations of BDE-47 in sediment have dropped by over one-third from 2002 to 2012; in water, a decline is not yet evident. The dominant congener in sediment, DecaBDE component BDE-209, showed no temporal trend. U.S. production of DecaBDE ended in 2013; future monitoring may reveal declines. Overall, the data indicate that reduced production can result in relatively rapid reductions in the concentrations of some hydrophobic contaminants in biota and sediment, particularly when implemented after only a few decades of heavy use. Recent changes to California's flammability standards may lessen the use of other flame retardants and similarly reduce Bay contamination. (Graph Presented). © 2014 American Chemical Society.

Benskin J.P.,AXYS Analytical Services Ltd. | Benskin J.P.,Canadian Department of Fisheries and Oceans | Ikonomou M.G.,Canadian Department of Fisheries and Oceans | Woudneh M.B.,AXYS Analytical Services Ltd. | Cosgrove J.R.,AXYS Analytical Services Ltd.
Journal of Chromatography A | Year: 2012

A rapid (<23. min) new HPLC-MS/MS method was developed for simultaneous characterization of 24 per- and polyfluoroalkyl compounds in landfill leachate. In addition to isomer-specific analysis of perfluorooctane sulfonate and perfluorooctanoate, branched from linear isomer separation was accomplished for C6 and C10 perfluoroalkyl sulfonates, C6, C7 and C9-C11 perfluoroalkyl carboxylates, perfluorooctane sulfonamide and, for the first time, 3 perfluorooctane sulfonamidoacetates. The method utilizes a fused-core pentafluorophenylpropyl (PFP) stationary phase and is approximately 4 times faster than previous comprehensive isomer-specific HPLC-MS/MS methods. This is the first isomer-specific methodology which can be adopted for routine analysis without sacrificing throughput from lengthy run times or limited target lists. © 2012 Elsevier B.V.

Benskin J.P.,AXYS Analytical Services Ltd. | Benskin J.P.,Canadian Department of Fisheries and Oceans | Ikonomou M.G.,Canadian Department of Fisheries and Oceans | Gobas F.A.P.C.,Simon Fraser University | And 2 more authors.
Environmental Science and Technology | Year: 2012

The environmental occurrence of perfluorooctane sulfonate (PFOS) can arise from its direct use as well as from transformation of precursors ((N-alkyl substituted) perfluorooctane sulfonamides; FOSAMs). Perfluorooctane sulfonamidoethanol-based phosphate (SAmPAP) esters are among numerous potential PFOS-precursors which have not been previously detected in the environment and for which little is known about their stability. Based on their high production volume during the 1970s-2002 and widespread use in food contact paper and packaging, SAmPAP esters may be potentially significant sources of PFOS. Here we report for the first time on the environmental occurrence of SAmPAP diester in marine sediments from an urbanized marine harbor in Vancouver, Canada. SAmPAP diester concentrations in sediment (40-200 pg/g dry weight) were similar to those of PFOS (71-180 pg/g). A significant (p < 0.05) correlation was observed between SAmPAP diester and N-ethyl perfluorooctane sulfonamido acetate (an anticipated degradation product of SAmPAP diester). ΣPFOS-precursor (FOSAM) concentrations in sediment (120-1100 pg/g) were 1.6-24 times greater than those of PFOS in sediment. Although SAmPAP diester was not detected in water, PFOS was observed at concentrations up to 710 pg/L. Among the per- and polyfluoroalkyl substances monitored in the present work, mean log-transformed sediment/water distribution coefficients ranged from 2.3 to 4.3 and increased with number of CF 2 units and N-alkyl substitution (in the case of FOSAMs). Overall, these results highlight the importance of FOSAMs as potentially significant sources of PFOS, in particular for urban marine environments. (Figure Presented). © 2012 American Chemical Society.

Benskin J.P.,AXYS Analytical Services Ltd. | Benskin J.P.,Canadian Department of Fisheries and Oceans | Li B.,University of British Columbia | Ikonomou M.G.,Canadian Department of Fisheries and Oceans | And 2 more authors.
Environmental Science and Technology | Year: 2012

Concentrations and isomer profiles for 24 per- and polyfluoroalkyl substances (PFASs) were monitored over 5 months (February-June, 2010) in municipal landfill leachate. These data were used to assess the role of perfluoroalkyl acid (PFAA) precursor degradation on changes in PFAA concentrations over time. The influence of total organic carbon, total suspended solids, pH, electrical conductivity (EC), leachate flow rates, and meteorological data (precipitation, air temperature) on leachate PFAS concentrations was also investigated. Perfluoropentanoate and perfluorohexanoate were typically the dominant PFASs in leachate, except for March-April, when concentrations of perfluorooctane sulfonate, perfluorooctanoate, and numerous PFAA-precursors (i.e., (N-alkyl) perfluorooctane sulfonamides and fluorotelomer carboxylic acids) increased by a factor of 2-10 (∼4 μg/L to ∼36 μg/L ∑PFASs). During this time, isomer profiles of PFOA became increasingly dominated by the linear isomer, likely from transformation of linear, telomer-manufactured precursors. While ∑PFAA-precursors accounted for up to 71% of ∑PFASs (molar basis) in leachate from this site, leachate from a second landfill displayed only low concentrations of precursors (<1% of ∑PFASs). Overall, degradation of PFAA-precursors and changes in leachate pH, EC, and 24-h precipitation were important factors controlling PFAS occurrence in leachate. Finally, 8.5-25 kg/yr (mean 16 kg/yr) of ∑PFASs was estimated to leave the landfill via leachate for subsequent treatment at a wastewater treatment plant. © 2012 American Chemical Society.

PubMed | Arcadis and AXYS Analytical Services Ltd
Type: | Journal: Journal of chromatography. A | Year: 2016

A high-resolution gas chromatography/high-resolution mass spectrometry (HRGC/HRMS) method was developed for quantitative analysis of hydroxy polycyclic aromatic hydrocarbons (OH-PAHs). Four hydroxy metabolites of known and suspected carcinogenic PAHs (benzo[a]pyrene (B[a]P), benz[a]anthracene (B[a]A), and chrysene (CRY)) were selected as suitable biomarkers of PAH exposure and associated risks to human health. The analytical method included enzymatic deconjugation, liquid - liquid extraction, followed by derivatization with methyl-N-(trimethylsilyl) trifluoroacetamide and instrumental analysis. Photo-induced oxidation of target analytes - which has plagued previously published methods - was controlled by a combination of minimizing exposure to light, employing an antioxidant (2-mercaptoethanol) and utilizing a nitrogen atmosphere. Stability investigations also indicated that conjugated forms of the analytes are more stable than the non-conjugated forms. Accuracy and precision of the method were 77.4-101% (<4.9% RSD) in synthetic urine and 92.3-117% (<15% RSD) in human urine, respectively. Method detection limits, determined using eight replicates of low-level spiked human urine, ranged from 13 to 24pg/mL. The method was successfully applied for analysis of a pooled human urine sample and 78 mouse urine samples collected from mice fed with PAH-contaminated diets. In mouse urine, greater than 94% of each analyte was present in its conjugated form.

Klosterhaus S.L.,San Francisco Estuary Institute | Grace R.,AXYS Analytical Services Ltd. | Hamilton M.C.,AXYS Analytical Services Ltd. | Yee D.,San Francisco Estuary Institute
Environment International | Year: 2013

Novel methods utilizing liquid chromatography-tandem mass spectrometry and gas chromatography-mass spectrometry were validated for low-level detection of 104 pharmaceuticals and personal care products ingredients (PPCPs) and four alkylphenols (APs) in environmental samples. The methods were applied to surface water, sediment, and mussel tissue samples collected from San Francisco Bay, CA, USA, an urban estuary that receives direct discharge from over forty municipal and industrial wastewater outfalls. Among the target PPCPs, 35% were detected in at least one sample, with 31, 10, and 17 compounds detected in water, sediment, and mussels, respectively. Maximum concentrations were 92. ng/L in water (valsartan), 33. ng/g dry weight (dw) in sediments (triclocarban), and 14. ng/g wet weight (ww) in mussels (N,N-diethyl-m-toluamide). Nonylphenol was detected in water (< 2-73. ng/L), sediments (22-86. ng/g dw), and mussels (< 0.04-95. ng/g ww), and nonylphenol mono- and diethoxylates were detected in sediments (< 1-40. ng/g dw) and mussels (< 5-192. ng/g ww). The concentrations of PPCPs and APs detected in the San Francisco Bay samples were generally at least an order of magnitude below concentrations expected to elicit toxic effects in aquatic organisms. This study represents the first reconnaissance of PPCPs in mussels living in an urban estuary and provides the first field-derived bioaccumulation factors (BAFs) for select compounds in aquatic organisms. © 2013 Elsevier Ltd.

Beesoon S.,University of Alberta | Genuis S.J.,University of Alberta | Benskin J.P.,University of Alberta | Benskin J.P.,AXYS Analytical Services Ltd. | Martin J.W.,University of Alberta
Environmental Science and Technology | Year: 2012

Perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA) are normally the dominant perfluoroalkyl substances (PFASs) in human serum, but here a Canadian family of seven was identified with particularly high exposure to perfluorohexanesulfonate (PFHxS). Disproportionately high serum PFHxS concentrations (range 27.5-423 ng/mL) and moderately high PFOS (range 15.2-108 ng/mL) and PFOA (range 2.40-9.23 ng/mL) concentrations were detected in the family members, with all three chemicals being highest in the youngest children. We therefore sought to identify the source(s) and pathway(s) of this unusual exposure, and to study the excretion of PFASs for this family. Serum, urine, and stool were sampled from family members, carpet, dust, and air were sampled in the home, and a questionnaire was administered. Over 15 years, the family's household carpets were treated 8 times with Scotchgard formulations. Elevated concentrations of PFHxS were detected in household dust (2780 ng/g dust) and in family room carpet (2880 ng/g carpet), and the primary mode of excretion for the major PFASs was through urine. The high PFHxS and moderately high PFOS concentrations in serum and household samples are consistent with the known PFAS content of certain Scotchgard formulations, and exposure was likely through dust ingestion and/or inhalation. © 2012 American Chemical Society.

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