Patrick W. Crozier

PERFLUORINATED PHOSPHONIC ACIDS IN CANADIAN SURFACE WATERS AND WASTEWATER TREATMENT PLANT EFFLUENT: DISCOVERY OF A NEW CLASS OF PERFLUORINATED ACIDS

The environmental prevalence of a new class of perfluorinated acids, the perfluorinated phosphonic acids (PFPAs), was determined in Canadian surface waters and wastewater treatment plant (WWTP) effluent. For quality control and comparison, the C8- to C11-perfluorinated carboxylic acids and perfluorooctane sulfonic acid were included in the analysis. Water samples were extracted using weak anion-exchange solid-phase extraction cartridges. Perfluorinated phosphonic acids were observed in 80% of surface water samples and in six of the seven WWTP effluent samples. The C8-PFPA was observed at concentrations ranging from 88 +/- 33 to 3400 +/- 900 pg/L in surface waters and from 760 +/- 270 to 2500 +/- 320 pg/L in WWTP effluent. To our knowledge, this is the first observation of PFPAs in the environment. Given their structural similarities with perfluorinated carboxylic and sulfonic acids, PFPAs are expected to be persistent. The observation of PFPAs in the majority of samples analyzed here suggests they are prevalent environmental contaminants and should be considered in future environmental monitoring campaigns to better understand the total burden of fluorinated materials in the environment.

Long-term environmental fate of perfluorinated compounds after accidental release at Toronto airport.

Perfluorooctane sulfonate (PFOS; a perfluorinated compound or PFC), its salts, and perfluorooctane sulfonyl fluoride have recently been listed in Annex B of the Stockholm Convention due to their widespread presence, persistence, and toxicity. Because of the persistent nature of PFCs, it is generally presumed that the impact of direct discharges of these chemicals on a receiving environment would be long-lasting. However, long-term environmental fate studies based on field measurements are rare. We examined spatial and long-term (9 year) temporal trends of PFCs in water, sediment, fish, and fish liver collected in 2003, 2006, and 2009 from 10 locations spanning ∼20 km in Etobicoke and Spring Creeks, where an accidental release of fire fighting foam containing PFOS from nearby Toronto International Airport occurred in 2000. Even a decade after the spill, sediment PFOS concentrations are still elevated in Spring Creek Pond which received the foam discharge; however, the major impact is relatively localized likely due to the stormwater management nature of the pond and the diluting effect of Etobicoke Creek. Fish and fish liver PFOS concentrations at a Spring Creek location downstream of Spring Creek Pond declined by about 70 and 85%, respectively, between 2003 and 2009. PFOS in water at locations further downstream in Etobicoke Creek have declined by >99.99% since the spill; however, the 2009 water and fish levels were ∼2-10 times higher than upstream locations likely due to the long-term impact of the spill as well as urbanization. The decrease in the upstream PFOS concentrations likely reflects the reduction of PFOS sources due to phased out production by 3M and regulations on the use of PFOS in fire fighting foams. Field-based sediment/water distribution coefficients (K(D)) and bioaccumulation factors (BAF) were calculated from environmental measurements. Log K(D) values were 0.54-1.65 for perfluoroalkyl sulfonates (PFASs) and 1.00-1.85 for perfluorocarboxylates (PFCAs). Log BAF(fish) ranged from 1.85 to 3.24 for PFASs and 0.88-3.47 for PFCAs, whereas log BAF(fish liver) ranged from 2.1-4.3 for PFASs and 1.0-5.0 for PFCAs.

Trace level determination of perfluorinated compounds in water by direct injection.

A new, fast LC-MS/MS method for the determination of perfluorinated surfactants in water samples by direct injection without pre-concentration is reported. The current method requires only 4 min to analyze nine perfluoroalkyl compounds in a single analytical run. Standard addition and internal standard quantification were used to determine the level of some perfluorinated carboxylic and sulfonic acids, including perfluorooctanoic sulfonate (PFOS) and perfluorooctanoic acid (PFOA), in Great Lakes water samples. Statistically significant differences were observed between the results obtained using different quantification methods. A relatively small difference between the PFOS values obtained with the standard addition method, with and without peak area normalization, clearly indicates that standard addition is the best quantification method when mass-labeled standards are not available. Based on the paired t-test statistical analysis, the concentrations calculated using external standardization were the least accurate, with the highest mean difference from the standard addition calculated values. Both PFOS and PFOA were present at less than 10 ng l(-1) in all Great Lake samples. Higher levels were detected in tributaries of Lake Ontario and effluents from sewage treatment plants.

Fate, distribution, and contrasting temporal trends of perfluoroalkyl substances (PFASs) in Lake Ontario, Canada

Lake Ontario water and sediment collected from tributary, nearshore, and open lake sites were analyzed for perfluoroalkyl substances (PFASs), namely perfluoroalkyl carboxylic acids (PFCAs, F(CF(2))(n)CO(2)(-); n=6-11,13) and perfluoroalkane sulfonic acids (PFSAs, F(CF(2))(n)SO(3)(-); n=6,8,10). Survey results of surface sediment and water indicated that shorter chained PFASs were predominant in and near urban/industrial area watersheds, while longer chained PFASs were predominant in fine-grained sediment from major depositional basins. Niagara River suspended solids (1981-2006) demonstrated temporal trends that may have been influenced by recent changes in North American production and use of PFASs. Perfluorooctane sulfonate (PFOS) reached a peak concentration in 2001 of 1.1 ng/g, followed by a decrease from 2001 to 2006 (half-life=9 years). Perfluorooctanoic acid (PFOA) increased from 2001 to 2006 (doubling time= 2 years) reaching a peak concentration of 0.80 ng/g. In contrast, three sediment cores from western, central, and eastern Lake Ontario showed increasing temporal trends to surface sediment for all PFASs. PFOA and PFOS concentrations increased from 1988 to 2004 (doubling time= ~ 4 years) in the western Lake Ontario core. The observed variations in temporal trends from different environmental compartments may be a result of the physico-chemical properties of PFASs, ongoing emissions, and the environmental transformation and degradation of PFAS precursor compounds.

Factors influencing trends of polychlorinated naphthalenes and other dioxin‐like compounds in lake trout (Salvelinus namaycush) from Lake Ontario, North America (1979–2004)

Concentrations of polychlorinated naphthalenes (PCNs) were determined in archived lake trout (Salvelinus namaycush) from Lake Ontario, North America, collected between 1979 and 2004 to evaluate their temporal trends and the factors influencing their trends. Concentrations of PCNs, as well as polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), and non- and mono-ortho-substituted polychlorinated biphenyls (DL-PCBs), which were measured for comparative purposes, declined by eight-, seven-, and fivefold, respectively, between 1979 and 2004. Apparent elimination rate constants (k2) were calculated as the slopes of the regression lines of concentration versus time for PCN, DL-PCB, and PCDD/F congeners to compare the rate of decrease among congeners within and between compound classes. The k2 values for PCNs that had two pairs or three adjacent carbons unsubstituted with chlorine (congeners that can be biotransformed by vertebrates) were not significantly different from zero, indicating no decline in fish. For PCN congeners having no adjacent carbons unsubstituted with chlorine, the k2 values generally increased with hydrophobicity and degree of chlorination. This pattern differed from that of PCDD/Fs and DL-PCBs and from previous findings for non-DL-PCBs, for which the rate of contaminant decline decreased with hydrophobicity, and the pattern also differed from expectations based on thermodynamics. Differences in the rate of decline of PCN congeners may be caused by changes in source or mixture formulations over time and/or metabolic dechlorination of the less stable, higher-chlorinated PCNs 73, 74, and 75 to lower-chlorinated congeners. Based on suggested dioxin toxic equivalency factors, PCN concentrations in these whole lake trout may be sufficient to trigger consumption restrictions in Ontario, Canada, and our results suggest that PCNs merit incorporation into monitoring and assessment programs.

Trace level analysis of polycyclic aromatic hydrocarbons in surface waters by solid phase extraction (SPE) and gas chromatography-ion trap mass spectrometry (GC-ITMS)

Ontario Provincial Water Quality Objectives for polycyclic aromatic hydrocarbons (PAHs) in surface waters require low parts per trillion (ng L(-1))/high parts per quadrillion (pg L(-1)) detection limits. To meet these monitoring requirements, a solid phase extraction-gas chromatography-ion trap mass spectrometry (SPE-GC-ITMS) method was developed. Seventeen priority PAHs commonly monitored in surface and drinking waters were examined using an external ionization ion trap mass spectrometer operated in selected ion monitoring (SIM) mode. Under 70 eV electron ionization (El) conditions, both the quantitative [M]+* ion and confirmatory [M - 2H]+* ion were formed in classical abundance ratios. Each of these ion species was isolated in the ion trap using a specific scan function. However, to overcome poor levels of confirmatory ion abundance which otherwise restrict PAH method detection limits (MDLs), the abundance of [M - 2H]+* ions was augmented during isolation by causing the dissociation of [M]+* with the broad-band waveform used for high mass ion ejection. Augmenting the [M - 2H]+* signal intensity facilitated the achievement of MDLs of approximately 1 ng L(-1). PAHs in surface water samples that were not detected by current Ontario Ministry of the Environment high-performance liquid chromatography (HPLC)-fluorescence and GC-single-stage quadrupole mass spectrometry methods were detected and quantified using the ion trap mass spectrometry SIM method. The data produced by all three methods on natural water samples fortified at sub-parts per billion (ppb) levels were comparable. When applied to Standards Council of Canada/Canadian Association for Environmental Analytical Laboratories (SCC/CAEAL, www.CAEAL.ca) accreditation audit samples, the SPE-GC-ITMS method results met all performance evaluation criteria.

Characterization of nonyl phenol ethoxylates in sewage treatment plants by combined precursor ion scanning and multiple reaction monitoring.

A novel rapid screening technique for the profiling of nonyl phenol ethoxylates (NPEs) in sewage treatment plant (STP) influent/effluent was developed using flow injection with atmospheric pressure ionization coupled to mass spectrometric analysis by combined precursor ion scanning and multiple reaction monitoring. The technique allows for total NPE concentrations as low as 50 parts-per-trillion to be detected in STP samples.

Congener specific determination of polychlorinated naphthalenes in sediment and biota by gas chromatography high resolution mass spectrometry

An isotope dilution congener-specific method for the determination of the most abundant and most toxic polychlorinated naphthalenes (PCNs) was developed using gas chromatography with high resolution mass spectrometry (GC-HRMS). The method was used to determine the concentration of 24 target congeners and total PCN concentrations in fish and sediment samples. Tissue samples were extracted using pressurized liquid extraction (PLE) and sediment samples were extracted using Soxhlet extraction. Sample extracts were cleaned up using either a manual two-stage open column procedure or an automated FMS Power Prep System with multi-analyte and multi-sample capability using a three-column cleanup procedure. Sediment extracts were cleaned up with a dual open column cleanup technique involving the use of both a multi-layered silica (silver nitrate/acid/base/neutral silica) column followed by column containing carbon-activated silica. Fish tissue extracts were cleaned up on the automated system involving the use of a high capacity ABN (acid/base/neutral column), carbon celite column, and a basic alumina column. The method is capable of producing instrument detection limits (IDLs) between 0.06 and 0.13pg for each PCN (on column), with method detection limits (MDLs) for the fish extracts ranging from 1.3 to 3.4pg/g (wet weight) and 0.46 to 1.2pg/g (dry weight) for sediments. The average accuracy of 34 spiked fish samples analysed over a period of several months was 100% with a precision (%RSD) of 12%. Similarly, the average accuracy for 28 spiked sediment samples was 104% with a precision (%RSD) of 12%. The application of the method to environmental samples was demonstrated through the analysis of sediment and fish samples obtained from Lake Ontario, Canada. The method is used both for the determination of 24 PCNs and to perform non-targeted screening for the remaining 51 PCN congeners, which are included in the total PCN quantification result. It is currently one of the most comprehensive and accurate congener-specific methods available and was developed from the existing techniques used for the determination of polychlorinated dioxins and furans to produce high quality data with only minor modifications in the clean-up procedure. It can therefore be readily adopted by other laboratories performing dioxin and POP analyses.