Hing-Biu Lee

Occurrence of alkylphenols and alkylphenol mono-and diethoxylates in natural waters of the Laurentian Great Lakes basin and the Upper St. Lawrence River

Nonylphenol and its ethoxylates are on the second priority substances list (PSL2) to determine if they are ‘toxic’ as defined under the Canadian Environmental Protection Act. This study addresses the need for data on their occurrence in surface waters and sediments in Canada. Samples of surface water from 35 sites in the Laurentian Great Lakes basin and the upper St. Lawrence River were analyzed for 4-nonylphenol (4-NP), nonylphenol ethoxylate (NPE1), nonylphenol diethoxylate (NPE2) and 4-tert-octylphenol (4-t-OP). Bottom sediment samples from nine heavily industrialized sites were also analyzed for the same chemicals. Measurable quantities of 4-NP and 4-t-OP were found in 24% of all water samples. Values ranged from <0.010 μg to 0.92 μg/l and from <0.005 to 0.084 μg/l for 4-NP and 4-t-OP, respectively. Of the surface water samples, 58% were found to contain NPE1 and 32% contained NPE2. Their concentrations ranged from <0.020 to 7.8 μg/l for NPE1 and from <0.020 to 10 μg/l for NPE2. All nine sediment samples contained 4-nonylphenol, with values ranging from 0.17 to 72 μg/g (dry weight). The majority of sediment samples also contained detectable levels of the other contaminants. A total of 66% of sediments had detectable amounts of NPE1 and concentrations ranged from <0.015 to 38 μg/g (dry weight), 66% of sediments had detectable amounts of NPE2 and values ranged from <0.015 to 6.0 μg/g (dry weight) and 89% of sediment samples had detectable amounts of 4-t-OP and values ranged from <0.010 to 1.8 μg/g (dry weight). The highest concentrations of the analytes found are well below acute toxicity thresholds, but in some cases there may be cause for concern with regard to long-term effects on reproductive health of fish.

Pharmaceutically active compounds in Atlantic Canadian sewage treatment plant effluents and receiving waters, and potential for environmental effects as measured by acute and chronic Aquatic Toxicity

Ten acidic and two neutral pharmaceuticals were detected in the effluents of eight sewage treatment plants (STPs) from across Atlantic Canada. Concentrations varied between nondetectable and 35 microg/L. The analgesic, nonsteroidal anti-inflammatory drugs ibuprofen and naproxen were predominant. Carbamazepine, a neutral compound used as an antiepileptic drug, was observed consistently at a median concentration of 79 ng/L. Acetaminophen was found in the effluents of the three largest mechanical STPs at a median concentration of 1.9 microg/L, but not in the lagoon treatment systems. The substantially longer hydraulic retention times may have contributed to more effective removal of acetaminophen in the lagoon treatment systems. Drugs generally were not detected at significant concentrations in the larger bodies of receiving water (Saint John River, Hillsborough River, and Bedford Bay, Canada). However, drug residues in the small receiving streams were 15 to 30% of the effluent median concentrations. Six compounds (caffeine, naproxen, salicylic acid, carbamazepine, metoprolol, and sotolol) were found to persist in a small stream for a distance of at least 17 km, suggesting that small stream exposure to pharmaceutically active residues may be relatively greater than that in large bodies of water. Bioassays assessing acute and chronic effects on four organisms were conducted on four high-use drugs: Acetaminophen, ibuprofen, naproxen, and salicylic acid (metabolite of acetyl salicylic acid). Results indicated no negative effects except for the chronic algal (Selanastrum capricornutum) growth test on ibuprofen (no-observed-effect concentration, 10 microg/L; lowest-observed-effect concentration, 32 microg/L). Effects of these four compounds on invertebrates and plants in the receiving environments are unlikely based on the concentrations measured.

Determination of nonylphenol polyethoxylates and their carboxylic acid metabolites in sewage treatment plant sludge by supercritical carbon dioxide extraction

A supercritical fluid extraction (SFE) method was developed for the extraction of nonylphenol polyethoxylate (NPnEO) non-ionic surfactants from dried sewage treatment plant sludge. Extraction was carried out at 80°C and 5100 p.s.i. with carbon dioxide using water as a modifier. The ethoxylates were analyzed by gradient high-performance liquid chromatography (HPLC) with an APS Hypersil column and a fluorescence detector (230 nm excitation and 300 nm emission). This SFE method was more time-efficient and it produced higher recovery than the traditional Soxhlet extraction and steam distillation techniques used for NPnEO in sewage sludge. The same procedure was also applicable to the coextraction of nonylphenoxyacetic (NP1EC) and nonylphenoxyethoxyacetic (NP2EC) acids, which were metabolites of the ethoxylates under aerobic conditions. Following an off-line methylation, analysis of the acids was achieved by GC-MS in selected ion monitoring mode. In a brief survey of sludge samples collected from nine sewage treatment plants across Canada, very high levels of nonylphenol mono- (NP1EO, 28–304 μg/g) and di-ethoxylates (NP2EO, 4–118 μg/g) were found. In contrast, the total polyethoxylate concentration (from 3 to 17 ethoxy units) was generally less than 50% of the sum of NP1EO and NP2EO in the same sample. NP1EC and NP2EC were found in only three of the seven samples tested, with concentrations ranging from 4 to 38 μg/g.

In situ extraction and derivatization of pentachlorophenol and related compounds from soils using a supercritical fluid extraction system

Abstract An in situ supercritical fluid extraction and derivatization procedure for the determination of pentachlorophenol (PCP) and related compounds from soil samples is described. Phenols are extracted from soil and acetylated in situ with supercritical carbon dioxide in the presence of triethylamine and acetic anhydride at a temperature of 80°C. Quantitative recovery of di-, tri-, tetra- and penta-chlorophenols was obtained by a 10-min extraction with carbon dioxide at 37.2 MPa (365 bar, 0.8 g/ml density) from soil samples fortified to 0.5 and 5 ωg/g levels. In a comparison study, the supercritical fluid extracton and the steam distillation methods both produced very similar results for pentachlorophenol and other chlorophenols in a reference sample. When this method is applied to contaminated soils samples collected in a wood treatment plant, results for chlorophenols in a sample can be obtained in approximately 90 min.

Supercritical carbon dioxide extraction of polycyclic aromatic hydrocarbons from sediments

Abstract A supercritical fluid extraction (SFE) method using carbon dioxide was developed for the determination of the 16 US Environmental Protection Agency pol

An Ecological Risk Assessment of Nonylphenol and Its Ethoxylates in the Aquatic Environment

Nonylphenol ethoxylates (NPEs) are a group of surfactants that are widely used for industrial, commercial, institutional and household purposes in Canada. Ethoxylation of nonylphenol (NP) occurs upon reaction with ethylene oxide, producing NPEs, although NP is also used in the production of the antioxidant tris(nonylphenol)phosphite. NP and NPEs are not produced naturally, and the primary route of environmental exposure to NP and NPEs is via textile mill, pulp and paper mill and municipal wastewater treatment plant effluents. NPEs occur as complex mixtures and are described by the average ethoxylate chain length, which ranges from 1 to 100. The environmental fate of NPEs is strongly dependent on the effluent and, the degree and type of treatment to which the effluent is subjected. An ecological risk assessment was performed to determine if exposure to NP and NPEs results in effects on the Canadian environment, based on current use patterns. The Canadian ecological risk assessment found that adverse effects on aquatic organisms are likely, although assumptions were made with respect to appropriate dilution factors.

Determination of nitrolotriacetic, ethylenediaminetetraacetic and diethylenetriaminepentaacetic acids in sewage treatment plant and paper mill effluents

A method for the determination of nitrilotriacetic (NTA), ethylenediaminetetraacetic (EDTA) and diethylene-triaminepentaacetic (DTPA) acids in sewage treatment plant (STP) and paper mill effluents has been developed. The chelating acids were extracted by solid-phase extraction cartridges packed with strong anion-exchange resins and were eluted by a small volume of 16 M formic acid. After conversion into their 1-propyl esters, the acids were quantified by gas chromatography using a nitrogen-phosphorus-selective detector and confirmed by GC-MS with a mass selective detector. At a pH of 3.5, the recovery of these acids varied from 83 to 104% in water and STP effluent samples fortified to levels from 1 to 1000 μg/1. Based on a concentration factor of 100, the detection limit for these acids was 0.5 μg/1. All three acids were found in STP effluents, although the concentrations were relatively low for EDTA ( 1000 μg/1) of NTA were observed for nearly all primary STP effluents. A large variation in the levels of these acids was observed in the paper recycling mill effluents collected. Although their concentrations were mostly 2500 μg/1) in the effluents obtained from two mills that use this chelating agent to remove metal ions. DTPA was not detected and the concentrations for NTA and EDTA were <11 μg/1 in the effluents collected from the non-recylcing paper mills.

Perfluoro and chloro amide derivatives of aniline and chloroanilines : A comparison of their formation and gas chromatographic determination by mass selective and electron-capture detectors

Abstract The preparation of the amide derivatives of aniline and 16 chloroanilines by reaction with trifluoroacetic, pentafluoropropionic, heptafluorobutyric, chloroacetic, and dichloroacetic anhydrides is described. Separation of these derivatives by capillary columns was investigated and mass spectral data of 85 derivatives obtained by mass selective detector were summarized. Electron-capture relative response factors of the amides were also obtained. A comparison of the five derivatization reactions indicated that the heptafluorobutyryl derivatives were most suitable for the analysis of the present group of anilines.

Supercritical carbon dioxide extraction of resin and fatty acids from sediments at pulp mill sites

Abstract A rapid and efficient method for the extraction of resin and fatty acids commonly found in sediments collected from pulp mill locations was developed by using modified supercritical carbon dioxide. In the presence of a 1:1 mixture of methanol and formic acid, quantitative recovery of all acids except for palustric and neoabietic acids was achieved with a 5 min static and 10 min dynamic extraction with carbon dioxides at 365 bar and 80°C. Although the above two resin acids were only 40% recovered from spiked samples, these values were at least 250% better than those obtained by the classical Soxhlet technique. The cleaner supercritical fluid extract permitted a less stringent cleanup after the off-line derivatization of the acids, thus it further reduced analytical time and the use of solvent. An in situ extraction and on-line derivatization of the resin and fatty acids also proved feasible for the semi-quantitative screening of the toxic acids in sediments near pulp mill locations.

Optimization of supercritical carbon dioxide extraction for polychlorinated biphenyls and chlorinated benzenes from sediments

Abstract A method for the simultaneous extraction of polychlorinated biphenyls (PCBs) and chlorinated benzenes in sediments using supercritical fluid extraction (SFE) technique was developed. The best recovery of the above chlorinated pollutants was obtained by using non-modified carbon dioxide at 35 MPa and an extraction temperature of 100°C with a sediment moisture content in the 11 to 50% range. Cleanup of SFE extract was performed on a miniature Florisil column followed by sulfur removal with mercury. PCB levels were quantitated by a mixture of selected PCB congeners using a mass-selective detector so that the level of each PCB homologue series as well as the total PCB concentration in the sample extract could be evaluated. Under the optimized conditions, an extraction time of only 21 minutes was needed to produce PCB results comparable to a 7-h Soxhlet extraction. Meanwhile, the SFE recovery of chlorinated benzenes was up to 50% higher than for the Soxhlet results due to lower evaporative losses in the former procedure.