Thomas E. Peart

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.

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.

Gas chromatographic and mass spectrometric determination of some resin and fatty acids in pulpmill effluents as their pentafluorobenzyl ester derivatives

Abstract A sensitive gas chromatographic method for the determination of resin and fatty acids commonly found in pulpmill effluents is presented. The acids are extracted from effluent samples at pH 8 by methyl tert. -butyl ether and converted into their respective pentafluorobenzyl ester derivatives. After silica gel column cleanup, sample extracts are analyzed by gas chromatography with an electron-capture detector using a 30-m DB-17 column. Mass spectral data of these esters obtained under electron impact and electron capture negative ion chemical ionization conditions are also described. The abundant and characteristic (M — 181) − ions are used for the identification and quantitation of resin and fatty acids using a selected ion monitoring technique. Using an effluent with a low blank, spiked recovery of a mixture of 15 acids at 1000-, 100- and 10-μg/1 levels is quantitative. Based on a 25-ml sample and a concentration factor of 10, the method detection limit is 1 μg/1 for all acids. Application of this procedure to some Canadian pulpmill samples is also presented.

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

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.

Determination of phenolics from sediments of pulp mill origin by in situ supercritical carbon dioxide extraction and derivatization

Abstract A method for the determination of extractable chlorinated phenolics in sediments collected downstream of chlorine-bleaching mills was developed by using a single-step in situ derivatization technique in conjunction with supercritical fluid extraction (SFE). Phenolics in air dried samples were extracted with carbon dioxide and simultaneously acetylated under static SFE conditions by acetic anhydride in the presence of triethylamine. The derivatives were then removed from the matrix in the dynamic extraction stage. Within an extraction chamber temperature range from 40 to 120°C, the best overall recovery for the phenolics was obtained at 110°C. A carbon dioxide density of 0.71 g/ml (pressure 37 MPa) was used for the extraction—derivatization experiments since lower CO 2 densities adversely affected the recovery of the catechols. Two extractions of the same sample were necessary for the quantitative recovery of extractable phenolics in weathered sediments. For sample size of 1 g, 120 μl of acetic anhydride and 30 μl of triethylamine were found to produce the optimal results. While the results obtained by this SFE—derivatization method were comparable to conventional technique such as Soxhlet extraction, the SFE approach required no solvent in the extraction steps and was extremely time-efficient ( ca. 35 min).

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.

Determination of resin and fatty acids in sediments near pulp mill locations

A gas chromatographic method for the determination of resin and fatty acids in sediments is described. In this procedure, the sediment sample was air-dried and soxhlet-extracted with a mixture of acetone--methanol (88:12, v/v) in the presence of hydrochloric acid. The acids extracted were converted into their pentafluorobenzyl esters and were then cleaned up on a deactivated silica gel column. Final analysis was performed on either a DB-17 or a DB-5 capillary column with electron-capture detection. Quantitative recovery was obtained from fortified sediments for all acids except palustric, neoabietic and levopimaric acids. The detection limit of all acids in this method was 0.1 micrograms/g based on 1 g of sample. This procedure has been successfully applied to the monitoring of resin and fatty acids in sediment samples collected in the vicinity of several Canadian pulp mill locations.