Anal. Chem. 1995, 67, 1976-1980
Determination of 4I"nylphenol in Effluent and Sludge from Sewage Treatment Plants Hing=biuLee* and Thomas E. Peart Priority Substances Project, Aquatic Ecosystem Protection Branch, National Water Research Institute, Environment Canada, P.O. Box 5050, Burlington, Ontario L7R 4A6, Canada
Quantitative and efficient methods for the determination of 4-nonylphenol(4-NP)in sewage treatment plant (STP) effluentand sludge samples were developed. For eftluent, the 4-NP was converted, in situ, into its acetyl derivative with acetic anhydride in the presence of a base. In the case of sewage sludge, 4-NPwas subjected to supercritical carbon dioxide extraction and on-line acetylation during the extraction stage. After a silica gel column cleanup, sample extract was analyzed by capillary column gas chromatography/mass spectrometry in the selected ion monitoring mode. Recoveries of 4-NP in spiked samples ( 1 and 10 pg/L for effluent and 5 and 50 pg/g for sludge) were 93%or above with relative standard deviations better than 5%. Detection limits for 4-NP were 0.1 pg/L for effluent and 0.1 pg/g for sludge. These methods were applied to the determination of 4-NP in samples collected from Toronto and vicinity STPs. Concentrations of 4-NP from < 1 to 30 pg/L in the effluent and > 100 pg/g in sludge were found. Nonylphenol ethoxylates (NPEs) are a major class of nonionic surfactant used across Canada. NPEs are derived from the addition of ethylene oxide to nonylphenol and may have 1-20 ethoxy units per molecule.' Nonylphenol, manufactured by the alkylation of phenol with nonene, consists mainly of a mixture of Csubstituted monoalkylphenols with various isomeric, branched nonyl groups. The demand for NPEs in Canada was 4.1 kton in 1990. While the use of NPEs in household detergents has diminished in recent years, the textile and pulp and paper industries are presently the major users of these surfactants. Under anaerobic condition^,^-^ NPEs ultimately biodegrade into Cnonylphenol (4-NP), which is persistent, lipophilic, and more toxic than the ethoxylates to fish and other aquatic organisms. Its 9&h LCSOvalues for salmon and trout ranged from 0.13 to 0.23 mg/L.s The occurrence of NPEs and their metabolites including 4 N P has been monitored in sewage treatment plant (STP) samples in some European countries since the early 1980s. Concentrations of 4-NP varied from < 1to 100 pg/L in e f f l ~ e n t ~and - ~ from $ ~ 100 to 1000pg/g in ~ l u d g e .With ~ , ~ a log KO,(octanol-water partition coefficient) of 4.48: 4-NP is expected to be adsorbed on sediments. (1) Ahel, M.; Giger. W. Anal. Chem. 1985,57,2584-2590. (2) Stephanou, E.; Giger, W. Environ. Sci. Technol. 1982,16,800-805. (3) Ahel, M.; Giger, W. Anal. Chem. 1985,57, 1577-1583. (4) Ahel, M.; Giger, W.; Koch, M. Water Res. 1994,28,1131-1142. (5) McLeese, D. W.; Zitko, V.; Sergeant, D. B.; Bunidge, L.; Metcalfe, C. D. Chemosphere 1981,10, 723-730. (6) Ahel, M.; Conrad, T.; Giger, W. Enoiron. Sci. Technol. 1987,21,697-703. (7) Giger. W.; Bmnner, P. H.; Schaffner, C. Science 1984,225,623-625.
1976 Analytical Chemistry, Vol. 67, No. 73,July 7, 7995
To date, very little information regarding the levels of 4-NP in Canadian STP effluent and sludge is available. The main environmental cause of NPEs and their metabolite 4 N P is from the use of detergents derived from this surfactant. Inputs from the other industrial applications of 4NP, such as pesticide adjuvants and polymerization emulsiiiers, are relatively minor. The presence of 4 N P in the environment has recently become of increasing concern since it has been shown to be a strongly estrogenic compound that can cause feminization of male fish downstream of !3TPs,S resulting in a lack of reproductive success. While the evidence is still fragmentary, these environmental estrogens, including compounds such as DDE, DDT, Kepone, some polychlorinated biphenyls, and alkylphenols, particularly nonyl- and octylphenols, are also linked to fertility problems in men and cancer in human^.^ In one study, 4 N P at 10 pM was shown to exhibit estrogenic effects similar to 30 pM of 17pestradiol in inducing the prolieration of MCF; human breast cancer cells.'') In the past, several extraction methods, including continuous solvent extraction, exhaustive steam distillation, and gaseous stripping with nitrogen into ethyl acetate using the Wickbold procedure, have been used for the enrichment of 4-NP in wastewaters and sewage e f f l ~ e n t . ~ , ~The J steam distillation method was also used for the extraction of 4-NP in sewage sludge and soil samples after the solids were suspended in water? While other chromatographic methods were developed,2J1quantitative analysis of 4-NP was usually carried out by normal phase HPLC analysis using an UV detector at 277 nm since this technique was more amenable to the simultaneous analysis of the polyethoxylatesS3In this work, we validate an in situ derivatization technique for the simultaneous extraction and acetylation of 4-NP in effluent, sludge, and sediment samples. Sample extracts were quantified by GC/MS operating in selected ion monitoring mode for sensitive detection and positive identification. The application of this technique to the determination of 4 N P and 4tert-octylphenol (4tOP) in effluent and sludge samples collected from nearby municipal STPs, as well as in some aquatic sediments, is also described. EXPERIMENTAL SECTION
Chemicals. 4-NP, 4tOP 4(1,1,3,3-tetramethylbutyI)phenol, 4n-octylpheno1, acetic anhydride, and triethylamine were obtained from Aldrich (Milwaukee,wr). Stock solutions of the phenols at (8) Ahel, M.; Giger, W. Chemosphere 1993,26,1471-1478. (9) Hileman. B. Chem. Eng. News 1994,Jan 31, 19-23. (10) Soto, A. M.; Justicia, H.; Wray, J. W.; Sonnenschein, C. Environ. Health Perspect. 1991,92, 167-173. (11) Giger, W.; Stephanou, E.; Schaffner, C. Chemosphere 1981,lO. 1253-1263. 0003-2700/95/0367-1976$9.00/0 0 1995 American Chemical Society
1000 pg/mL were prepared in acetone and stored in crimped top vials at 4 "C. Non-acid-washed Celite 545, anhydrous sodium sulfate, potassium carbonate, and silica gel (GC grade 950, 60200 mesh) were purchased from Fisher Scientific Co. (Toronto, Canada). Acetic anhydride was triply distilled in our laboratory and kept at -20 "C. Sodium sulfate was heated to 500 "C overnight, cooled, and stored in glass bottles before use. Silica gel was activated at 200 "C overnight and then deactivated by adding 5 mL of water to 95 g of the adsorbent. Solvents (hexane, petroleum ether 30-60 "C, acetone, and isooctane) were distilledin-glass grade available from Baxter (Burdick and Jackson, Muskegon, WI), Supercriticalfluid extraction (SFE)grade carbon dioxide without a helium head pressure was obtained from Air Products (Nepean, Canada). Effluent and Sludge Samples. Samples from STPs in metropolitan Toronto (four sites: Leslie, Humber, Highland Creek, and North Toronto) and Mississauga (Lakeview) were tested in this work. Up to three effluent samples (1-4 L grab) were collected at each site: primary effluent, final effluent before chlorination, and final effluent after chlorination. Heat-treated sludges were collected from the Leslie and Highland Creek plants. No preservative was used for these samples. After collection, each effluent was filtered through 0.45 pm Whatman GF/C filters, kept at 4 "C, and extracted the following day. Sludge and sediments were air-dried at 22 "C, ground, and passed through a 30 mesh sieve to remove extraneous matters such as hair, wood chips, and gravel. The homogenized powder was used for SFE work. In Situ Acetylation of 4-NP in Effluent. To 250 mL of a filtered effluent was added 1 g of potassium carbonate to bring the pH to 10 or above. To this was added 1 mL of the triple distilled acetic anhydride was added, followed by 30 mL of petroleum ether, and the sample was stirred on a magnetic stirrer for 30 min. The layers were then separated in a separatory funnel, and the aqueous layer was returned to its original container. The acetylation was repeated twice with an additional 100pL of acetic anhydride and 30 mL of petroleum ether for 15 min each time. The combined organic extract was partitioned with 30 mL of 1% potassium carbonate solution to remove the coextracted acetic acid. After the base was discarded, the organic layer was dehydrated by passing through a 2.5 cm layer of anhydrous sodium sulfate in a filter funnel and concentrated to -5 mL with a rotary evaporator and a 40 "C bath. The concentrated extract was quantitatively transferred to a 15 mL test tube and further evaporated, by a gentle stream of nitrogen, to 1mL in the presence of 1 mL of isooctane as a keeper. In Situ Acetylation and SFE of 4-NP from SI" Sludge. AU SFE was carried out with a Hewlett-Packard 768OT supercritical fluid extractor. The extraction thimble was prepared as follows. First, a layer of Whatman GF/C filter paper cut to the diameter of the thimble was placed at the bottom of the thimble, makiig sure that it did not interfere with the sealing surface of the cap. Next, 200 mg of Celite followed by 250 mg of a dry sludge or 1g of a dry sediment was added. A 30 p L portion of triethylamine was then spiked onto the sample, followed by another layer of Celite (200 mg) and 100 p L of acetic anhydride. Another layer of GF/C filter paper was placed on top. The void volume of the extraction thimble was filled by a glass rod of 1 cm diameter and a suitable length (3-5 cm, depending on the sample size). The samples were extracted with supercritical carbon dioxide at 80 "C and a density of 0.79 g/mL (5096 psi) at a flow rate of 2
mL/min. The extraction times were 15 min static and 10 min dynamic. The variable restrictor nozzle was kept at 50 "C to prevent freezing. The acetyl derivative of 4NP formed during the static extraction was removed from the sample matrix in the dynamic extraction stage. After depressurization of the supercritical fluid, the extract was adsorbed on an octadecyl functionalized silica gel (ODS) trap which was maintained at 5 "C during extraction. At the end of the extraction, the trap was heated to 40 "C before the derivatives were eluted from the trap by 1.5 and 1.0 mL aliquots of hexane into two vials. The extracts were combined in a 15 mL tube and partitioned with 3 mL of 1% potassium carbonate solution to remove the coextracted acetic acid. The organic layer was then dried with anhydrous sodium sulfate and concentrated to 1 mL with nitrogen in a 40 "C bath. Silica Gel Column Cleanup. To clean up all derivatized effluent and sludge extracts, a column made of a 7 mm i.d. disposable Pasteur pipet with a piece of glass wool plug at the bottom was prepared. The column was filled 5 cm of 5% deactivated silica gel and then with 5 mm of anhydrous sodium sulfate. After pre-elution with 3 mL of petroleum ether, the concentrated sample extract was quantitatively applied to the column. It was then sequentially eluted by the following: (1) 5 mL of 5%dichloromethane in petroleum ether, (2) 10 mL of 50% dichloromethane in petroleum ether, and (3) 10 mL of 1% methanol in dichloromethane. Fraction 1 was discarded. Fractions 2 and 3 were collected separately, and each fraction was solvent exchanged into 1 mL of isooctane. Gas Chromatography/Mass Spectrometry (GC/MS) Analysis. GC/MS analysis of sample extracts was performed with a Hewlett-Packard (HP) 5972 mass selective detector (MSD) interfaced to a HP5890 Series I1 gas chromatograph (GC). For most samples, only fraction 2 from the silica gel column cleanup that contained the acetyl derivative of 4NP was analyzed. Sample injection was made, in the splitless mode, by the HP7673A autosampler onto a 30 m x 0.25 mm i.d. x 0.25 pm HP-SMS column. Injection port and detector interface temperatures were 250 and 280 "C, respectively. The GC oven temperature program was 70 "C initial (kept for 1 min), increased to 160 "C at 30 "C/ min, then increased to 240 "C at 5 "C/min. Camer gas (helium) linear velocity was held constant at 39.8 cm/s by means of an electronicpressure controller. The electron energy and electron multiplier voltage were 70 eV and ZOO0 V, respectively. Confumation of samples was carried out in full scan mode, and data were acquired from m/z 40 to 300. Quantitative analysis of the Cnonylphenyl acetate was performed by monitoring the ions at m/z 107, 121, 135, 163, 191, and 262 in selected ion monitoring (SIM) mode. For 4tert-octylphenyl acetate, the ions at m/z 135, 177, and 248 were monitored. Calibration Standards and Quantiilcation. Calibration standards were prepared by acetylation of a mixture of 4NP (100 pg) and 4tOP (10 pg) in 30 mL of 1%%COS in the presence of acetic anhydride as described above for effluent samples. Further dilutions of the product were made in isooctane to prepare standard solutions at 10, 1, and 0.1 pg/mL for Cnonylphenyl acetate and 1, 0.1, and 0.01 pg/mL for 4tert-octylphenyl acetate. Confirmation of peak identity was achieved by the observation of molecular ions at m/z 248 (for 4tOP) and 262 (for 4NP). Quantification of the phenols in sample extracts was carried out by the external standard method using response factors generated by the authentic standards prepared above. Each sample extract Analytical Chemistty, Vol. 67,No. 13, July 1, 1995
1977
was injected twice, and the average result was used. For extracts with 4NP and 4tOP concentrations higher than the calibration standards, the samples were further diluted and reanalyzed. Response factors were recalibrated once every three samples. For 4NP, summation of areas was performed for those peaks that had the same retention times as the calibration standard as well as the presence of the confirmation ion m/z 262 in the SIM traces.
Abundance 2000000
Lime -
- >O
1
y v \I YIVh' ,
8.00
'
9.00
10.00 11.00 scan. 323 ( 9 .a26 mint: o 1 0 1 0 0 1 . ~
undance
RESULTS AND DISCUSSION
A
L3
'I1
B
163
In Situ Acetylation of 4-NP. A wide range of phenolic compounds of environmental importance react readily and quanI 50000 titatively with acetic anhydride to form the acetyl derivatives. 219 262 These include priority pollutants such as chl~rophenols,~~-~* 1, A0 i b b '210 '240 ' i kb' methylphenols,12and nitrophenols'5 as well as the chlorinated . l i d mint: 0101001.0 n guaiacols, catechols,and syringols found in effluent from chlorine bleaching pulp and paper mills."j Even though gas chromatographic methods have been established for underivatized 4NP, the less polar acetyl derivative is our choice for this work since it offers better chromatographic separation of the 4NP isomers as well as a lower (-4fold) detection limit by G U M S in SIM mode. The extraction of 4nonylphenyl acetate in effluent could be Abundance scan 355 (10,102 m i n ~: 0101001.0 D effected by a nonpolar solvent such as petroleum ether, and the 200000 emulsion formed during the extraction steps was never severe 12' 135 l]/ 191 enough to affect phase separation. Further, the derivative is more 100000 readily separated from the more polar coextractives by the silica 43 I gel cleanup column, and it is therefore advantageous in the analysis of highly contaminated effluent and sludge samples. While the derivahtion route has an extra step in the procedure, it does Figure I. (A) Total ion current chromatogram of the acetyl not require any extra time since the extraction and acetylation of derivatives of 4-tert-octylphenol (retention time, 8.70 min) and 4-NP 4NP can be carried out simultaneously. (retention times, 9.8-10.9min). (B) Mass spectrum of peak 2 in the TIC chromatogram. (C) Mass spectrum of peak 3 in the TIC Electron Impact Mass Spectra of Acetyl Derivatives of chromatogram. Those for peaks 5 and 9 are similar. (D) Mass 4.". F i r e lA is a total ion current m C ) profile of the acetyl spectrum of peak 4 in the TIC chromatogram. Those for peaks 6 , 10 derivatives 4tOP and 4NP chromatographed on a 5% phenyl and 11 are similar. methyl polysiloxane phase capillary column. Peak 1, with a retention time of 8.70 min, was derived from 4tOP, while those m/z 135 ([M - COCHz - CsH131f), suggesting that they have an peaks from 9.8 to 10.9 min (peaks 2-11) were attributed to the a,adimethyl structure (Figure 1C). The third group of isomers different isomers of 4nonylphenyl acetate. Under the GC condi(peaks 4,6,10, and 11)had a base peak at m/z 149 ([M - COCH, tions described earlier, 10 peaks were resolved for the derivatized C5Hlllf) and are consistent with structures having a-methyl4NP, and they all had retention times longer than the free phenol. aethyl side chains ( F i i r e 1D). The mass spectrum of peak 7 The mass spectra of these peaks exhibited the same molecular had major fragments at m/z 219,177 (base peak, [M - COCH2 ion of m/z 262 with a relative intensity of 5%or less, confirming C3H7]+), 135,121, and 107 in addition to the weak M+. Since the the formation of acetyl derivatives. Other than the molecular ion, first three ions were 42 mass units apart and the last three were the mass spectra of the derivatives are very similar to those of 14 mass units apart, a CS side chain with two propyl groups and the free phenol, with intense fragment ions at m/z 107,121,135, an ethyl group attached to the benzylic carbon was assigned to 149, and 191.2J1 this isomer. On the basis of the presence of major fragments at A closer inspection of these mass spectra indicated that, with m/z 205 ([M COCHz CH31+), 163 (base peak, [M - COCHz the exception of peaks 7 and 8, the nonylphenol isomers could CdHgl+), 121, and 107 in the mass spectrum of peak 8, an alkyl be classified into three groups. The mass spectrum of the group structure with a methyl, a propyl, and a butyl substitution at the 1 isomer (peak 2 in Figure IA)is shown in Figure 1B. With a a carbon was tentatively assigned to this nonylphenol isomer. The base peak at m/z 121 ([M - COCH2 - C7H151+), it is consistent mass spectrum of Ctert-octylphenyl acetate closely resembled that with a resonance stabilized, substituted benzyl ion having the in Figure lC, with the exception of the molecular ion occurring a-methyl structure on the alkyl chain. The group 2 isomers at m/z 248. With a base peak at m/z 135, it was again consistent (peaks 3, 5, and 9) exhibited mass spectra with a base peak at with an a,a-dimethyl structure. Meanwhile, the mass spectrum of Cti-octylphenyl acetate exhibited a base peak at m/z 107, (12)Coutts, R T.;Hargesheimer, E. E.; Pasutto, F. M. J. Chromutogr. 1979, 179.291-299. indicating no branched alkyl substitution at the a carbon. (13)Abrahamsson, IC;Xie, T.M. J. Chromutogr. 1983,279,199-208. The GC/MS selected ion monitoring technique offers selective (14)Lee, H. B.;Weng, L. D.; Chau, k S.Y. J. Assoc. Off: Anal. Chem. 1984,67, detection and conhnative results for 4NP in highly contaminated 789-794. (15) Coutts, R T.;Hargesheimer, E. E.; Pasutto, F. M. J. Chromutogr. 1980, STP samples, goals that could not be achieved by the previously 195,105-112. reported GC-FID and HPLC methods. Furthermore, the high (16)Lee, H. B.;Hong-You,R L.; Fowlie, P. J. A. J. h o c . @T Anal. Chem. 1989, resolution of the capillary column also permitted the simultaneous 72.979-984.
1
1978 Analytical Chemistry, Vol. 67, No. 13, July 1, 1995
Table I.Recovery of 4-Nonylphenol from Spiked Water and Sediment Samples'
matrix lake water
lake water lake sediment lake sediment
spiking level
mean recovery, %
RSD, %
10 pg/L 1P d L 50 pg/g 5P d g
93 97 96 98
3.2 4.1 4.5 5.3
Four replicates at each spiking level.
determination of octylphenol; the latter coeluted with nonylphenol under normal phase HPLC conditions. Supercritical Carbon Dioxide Extraction and in Situ Acetylation of 4-NPfrom Sludge and Sediments. A few years ago, we developed a highly efficient and selective extraction method for the determination of pentachlorophenol and other chlorophenols in contaminated soil and sediment ~amp1es.I~In that procedure, chlorophenols were lirst extracted by supercritical carbon dioxide and then acetylated by acetic anhydride in the presence of triethylamine under SFE conditions. This single-step procedure was later applied to the online SFE and acetylation of phenolics such as chlorinated guaiacols, catechols, and syringols in sediments collected downstream of chlorinebleaching pulp and paper mills.ls Unpublished work from our laboratory also indicated that the same procedure could be extended to the determination of priority pollutants such as methylphenols and nitrophenols in soils and sediments. 4 N P in sludge and sediments was readily extracted and acetylated by supercritical carbon dioxide of 0.79 g/mL density at a temperature of 80 "C. Using an air-dried and homogenized sludge collected from a Toronto STP as a reference sample for method development, quantitative recovery of 4 N P was achieved by a 15 min static extraction followed by a 10 min dynamic extraction at a flow rate of 2 mL/min. These SFE conditions were used for the subsequent determination of 4 N P in sludge and sediments since higher extraction temperature (100 "C) and higher carbon dioxide density (0.87 g/mL), as well as a doubling in extraction times (static and dynamic) or the amount of derivatization reagents, all failed to yield more 4NP. A second extraction of the same sample recovered less than 0.5%more 4NP. The entire extraction/acetylation cycle required -45 min. For comparison, 1 g of the same sludge used for SFE work was dispersed in 300 mL of water and then steam distilled for 3 h into 3 mL of c y c l ~ h e x a n eThe . ~ ~ organic layer was subsequently acetylated and the products were cleaned up as described before. However, in three trials, the recovery of 4 N P obtained by steam distillation was less than 8%of the SFE results. Recovery of 4-NPfrom Spiked Samples. Subsamples of a Burlington Bay water spiked with 4 N P were extracted by the in situ acetylation procedure described above. Replicate analyses at 1and 10pg/L levels produced recoveries of 293%with relative standard deviation better than 5% (Table 1). These results are similar to those obtained for the di- and trimethylphenols in our laboratory. In the case of sludge, a lake sediment free from 4 N P (17) Lee, H. B.; Peart, T. E.; HongYou, R L. 1.Chromatogr. 1992,605, 109113. (18) Lee, H. B.; Peart, T. E.; Hong-You, R. L. 1.Chromatogr. 1993,636, 263270. (19) Veith, G. P.; Kws, L. M. Bull. Enuiron. Contam. Toxicol. 1977,17, 631636.
Table 2. Levels of 4-Nonylphenol and 4-tert-Octylphenol in Municipal Sewage Treatment Plant Effluent
sewage treatment plant Mississauga (Lakeview)
Toronto (Leslie) Toronto (Highland Creek) North Toronto Toronto (Humber River)
A,
effluent
[4-NPl,
typea
PCgL
primary pnmary
12.7 30.0 15.1
final A final B primary final A final B Primary final A final B primary final A final B
15.0
4.0 1.9 1.4 2.8 3.0 1.2 4.4 1.0
0.8
[4-tOPl, PdL 0.9 2.5 1.6 1.7
1.1 0.77
0.69 0.48 0.23 0.17 0.41 0.12 0.19
prechlorination; B, postchlorination.
contamination was used for spiking purpose. Replicate analyses at spiking levels of 5 and 50 pg/g also produced results with acceptable precision and accuracy (Table 1). The detection limits of 4 N P were estimated as 0.1 pg/L for effluent (based on a concentration factor of 1OOO) and 0.1 pg/g for sludge and sediment (based on a concentration factor of 1). With the same concentration factors, the detection limits for 4tOP were 0.005 pg/L (effluent) and 0.005pglg (sludge and sediment). These detection limits easily attained the purposes of monitoring 4 N P in STP samples. Occurrence and Levels of 4-NPin !3"Samples and Some Aquatic Sediments. Effluent samples from four STPs in metropolitan Toronto and another STP in the nearby city of Mississauga were collected and analyzed for 4NP. The results vable 2) indicated that the phenol was found in all samples and its level varied from 2.8 to 30 pg/L in the primary effluent and from 0.8 to 15 pg/L in the postchlorination final effluent. There was a 2- to 5fold decrease in 4 N P between the primary and final effluent tested. Chlorination of the final effluent did not seem to have a significant impact on the level of 4 N P since its level was virtually the same before and after this process. In addition to 4NP, 4tOP was also present in all effluent samples, with concentrations varying from 0.12 to 2.5 pg/L. The environmental occurrence of 4tOP ethoxylate, possibly a minor component in NPE formulations, in the Delaware River has been reported.2O In contrast, 4noctylphenol was not detected in the effluent samples tested. It was noted that, in a spiked water sample, the recoveries for 4noctylphenol, 4NP, and 4tOP were similar. Under the same GC conditions, the retention time for 4n-octylphenyl acetate, 11.10 min, was longer than those for Cnonylphenyl acetate. The two sludge samples collected inside the Toronto STPs are contaminated with very high levels of 4NP, 470 and 137 pg/g on a dry weight basis (Table 3). A Hamilton Bay sediment that was collected near the Burlington STP effluent outlet was found to have 41 pg/g 4NP. Another sediment in the nearby Windermere Basin, which receives STP effluent from the city of Hamilton, had 6.73 pg/g 4NP. Three river sediments, collected at various sites downstream of pulp and paper mills in Thunder Bay in 1991,were also shown to be contaminated by 4NP, although the levels were low (0.29-1.28 pg/g) in comparison with the STP related samples. (20) Sheldon, L. S.; Hites, R A Sci. Total Enuiron. 1979,11,279-286.
Analytical Chemistry, Vol. 67, No. 13, July 1, 1995
1979
Table 3. Concentrations of 4-Nonylphenol and 4-tert-Octylphenol in Sewage Treatment Plant Sludge and Aquatic Sediments
sample type
1ocation
Toronto (Leslie) Toronto (Highland Creek) Hamilton Bay near the Burlington STP outlet Hamilton Bay (Windemere Basin) Hamilton Bay (the “deep hole”) Humber River Kaministiquia River (site A) Kaministiquia River (site B) Kaministiauia River (site C)
,
bundance 40000
STP sludge STP sludge
T I C : 0201003.0
A
35000
I
25000
4
20000 15000 10000 5000
ime--s bundance
8 00
1
10 00 0401005 D
11 00
TIC
9 00
10 0 0
11 0 0
9 00
B
70000 60000 -
ime-->
8 00
470 i 22 (n = 6) 137 i 7.7 (n = 3)
sludge/sediment mix sediment sediment sediment sediment sediment sediment
I
30000
[4-NPl,p d g
(A) Total ion current chromatogram of the acetyl derivatives of (A) a STP primary effluent contaminated by 4-NP and (B) a STP sludge
Figure 2.
Again, 4-tOP was found in many of these sludges and sediments, with concentrations varying from
