Environ. Sci. Technol. 2001, 35, 4015-4025
Halogenated Organic Contaminants in Sediments of the Havel and Spree Rivers (Germany). Part 5† of Organic Compounds as Contaminants of the Elbe River and Its Tributaries J A N S C H W A R Z B A U E R , * ,‡ MATHIAS RICKING,§ STEPHAN FRANKE,‡ AND WITTKO FRANCKE‡ Institute of Organic Chemistry, University of Hamburg, Martin-Luther-King-Platz 6, 20146 Hamburg, Germany, and Department of Earth Sciences, Free University of Berlin, Malteserstrasse 74-100, 12249 Berlin, Germany
To give a detailed and comprehensive view on the state of pollution of the Havel and Spree rivers nontarget screening as well as quantitative (target) analyses were applied to anoxic sediment samples. Based on nontarget GC/MS analysis a significant contribution to the anthropogenic contamination could be attributed to halogenated compounds. Three groups of contaminants corresponding either to diffuse or local contamination could be distinguished. Several commonly observable compounds including pentachloroanisol, polychlorinated biphenyles, 2,4-dichlorobenzoic acid, and chlorinated benzenes were detected with a distribution reflecting the contribution of nonpoint source emissions. A second group of chlorinated as well as brominated compounds was attributed to a strong point source emission at the Teltow Canal. At the sampling locations influenced by this point source the amount of mono- and dibrominated naphthalenes, chlorinated naphthalenes, and hexachlorocyclohexanes as well as DDT- and methoxychlorrelated compounds increased significantly as compared to the background concentrations. A third group of halogen compounds emitted at this site consisted of the pesticides bromopropylate, methoxychlor, and chlorfensone as well as specific brominated aromatics including 2,4,6tribromoaniline, 4,4’-dibromobenzophenone, and brominated benzenes. In addition, tetrabromochlorotoluenes, tribromodichlorotoluenes, dibromotrichlorotoluenes, and 2,2-bis(4-bromophenyl)acetic acid isopropyl ester were identified and are reported for the first time as environmental contaminants. The amounts of brominated compounds detected in Teltow Canal sediments occurred at a similar concentration level as their chlorinated analogues. Therefore, investigations on the occurrence of such a broad spectrum of brominated compounds as established in this work are presumably required more frequently to assess the environmental impact of this type of emissions.
Introduction Organic compounds of riverine sediments reflect both the biogenic input as well as anthropogenic emissions. Anthro10.1021/es010084r CCC: $20.00 Published on Web 09/01/2001
2001 American Chemical Society
pogenic contaminants can be attributed either to point or nonpoint sources, and with respect to their physicochemical properties and different transport processes a widespread or a localized distribution within the aquatic environment can be observed (1). GC/MS-screening analyses proved to be an important approach to provide comprehensive information about the state of pollution in riverine systems. For example, in water and sediment samples of the Elbe river system in Germany, a wide variety of organic compounds was identified, that was either specific for individual emissions or suitable for tracing the contribution of selected tributaries to the pollution of the Elbe river. Some of the substances have been formerly not reported as environmental contaminants (2-5). GC/MS nontarget screening analyses were also applied to the particulate matter in Havel and Spree rivers, important tributaries to the Elbe river. These rivers are situated in the northeastern part of Germany with a confluence in the urban area of Berlin. Especially this region is highly contaminated due to human activities and resulting emissions. Previous studies assessed the anthropogenic contribution to their pollution using selected common pollutants (e.g. dichlorodiphenyltrichloroethane (DDT), polychlorinated biphenyls (PCB), hexachlorocyclohexanes (HCH), chlorinated benzenes, and terphenyls) (6-9). In addition, a strong local emission source situated at the Teltow Canal (see Figure 1) was located. The high amounts of DDT and related compounds detected in water and sediment samples had been introduced by a former chemical plant (10, 11). However, based on GC/MS-screening analyses we identified and quantified a variety of organic contaminants in river sediments. Among the detected compounds an important contribution of halogenated substances was observed. This paper presents and discusses the occurrence, spatial distribution, sources, and quantitative results of common as well as especially unusual and rarely or previously not reported halogenated environmental contaminants identified in sediments of the Havel and Spree rivers.
Materials and Methods Samples. Within the urban area of Berlin the eutrophic to hypertrophic riverine system of the Havel and Spree is enlarged by several canals, connecting the Havel and Spree river upstream of their confluence, and numerous lake-like broadenings, with very slow flowing conditions. In these regions the sedimentation rates are very high, accompanied by high total organic carbon (TOC) contents up to 15% (see Tables 1 and 5). Sampling locations were mainly situated in these sedimentation areas and are illustrated in Figure 1. All sediment samples were collected in 1993/4. Surface sediment samples (S1-S14, H1-H4, H6, H9, T1, T4-T6) were taken with an Ekman-Birge-grab sampler which yielded up to 20 cm of the top sedimentary layer. Sediment cores from the sampling locations H5, H7, H8, T2, and T3 were obtained using a deep freezing method. A stainless steel bar with an external diameter of 8 cm was drilled into the upper layer (ap* Corresponding author phone: +49 241 805750; fax: +49 241 8888152; e-mail:
[email protected]. Present address: Institute of Geology and Geochemistry of Petroleum and Coal, Aachen University of Technology, Lochnerstrasse 4-20, 52056 Aachen, Germany. † Part 4: Schwarzbauer, J.; Franke, S.; Francke, W. Fresenius J. Anal. Chem. 1999, 365, 529-536. ‡ University of Hamburg. § Free University of Berlin. VOL. 35, NO. 20, 2001 / ENVIRONMENTAL SCIENCE & TECHNOLOGY
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FIGURE 1. Sampling locations of Havel and Spree river sediments (S ) Spree, H ) Havel, T ) Teltow Canal). proximately 1-2 m) of the sediments and subsequently filled with liquid nitrogen. After 30-60 min frozen sediment cores with a thickness of approximately 20-30 cm and a length up to 2 m were obtained. The investigated sediment layers representing an accumulation time from 1960 to 1993. Extraction and Fractionation. The procedures used for extraction of organic compounds from sediments and for subsequent fractionation as well as the determination of dry weights are described elsewhere (5, 12). Briefly, a high-speed dispersion tool was used for a sequential extraction procedure with mixtures of hexane and acetone. After drying the crude extracts and removal of elemental sulfur by activated copper powder, a separation into six fractions was carried out by micro silica column chromatography using mixtures of pentane, dichloromethane, and methanol. Acidic compounds in the methanol fraction were methylated by addition of a methanolic diazomethane solution. Prior to analysis, 50 µL of an internal standard containing 3.3 ng d8-naphthalene/ µL, 3.3 ng d10-fluorene/µL, 3.3 d10-phenanthrene/µL, 4.5 ng 4016
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d10-pyrene/µL, 3.1 ng d12-benz[a]anthracene/µL, and 3.0 ng d12-perylene/µL (all purchased from Promochem GmbH, Wesel, FRG) in n-hexane were added to each sample, and the volume was reduced to 50 µL by rotary evaporation at ambient temperature. Gas Chromatographic Analyses. Gas chromatographic analyses were carried out on a Mega Series HRGC 5300 gas chromatograph (Carlo Erba Instruments, Milano, I) equipped with a 25 m × 0.25 mm i.d. × 0.25 µm film DB5 fused silica capillary column (J&W Scientific, Folsom, U.S.A.). The end of the capillary column was connected to an eluate-splitter for simultaneous detection of the analytes with flame ionization (FID) and electron capture detectors (ECD, with nitrogen make up gas). Chromatographic conditions were as follows: 1 µL split/splitless injection at 60 °C, splitless time 60 s, 3 min hold, then programmed at 3°/min to 300 °C, hydrogen carrier gas velocity 35 cm/s. Gas Chromatographic/Mass Spectrometric Analyses (GC/MS). GC/MS analyses were performed on a VG 70-250
TABLE 1. Results of GC/MS Screening Analysis and Halogenated Organic Compounds Identified in Havel and Spree River Sediments by Full Scan Mass Spectraa sample code (Figure 1) sampling site
TOC (%)
H3
H6
S2
S9
S10
S13
S14
Chlorinated Arenes chlorobenzene 1,3-dichlorobenzene 1,4-dichlorobenzene 1,2-dichlorobenzene 1,3,5-trichlorobenzene 1,2,4-trichlorobenzene 1,2,3-trichlorobenzene 1,2,3,5-/1,2,4,5-tetrachlorobenzene 1,2,3,4-tetrachlorobenzene pentachlorobenzene hexachlorobenzene dichlorostyrene (3 isomers) trichlorostyrene (1 isomer) tetrachlorostyrene (1 isomer) hexachlorostyrene (1 isomer) heptachlorostyrene (1 isomer) octachlorostyrene PCB 2-chloronaphthalene 1-chloronaphthalene 1,3-dichloronaphthalene 1,4-dichloronaphthalene 1,5-/1,6-dichloronaphthalene 1,7-/2,6-/2,7-dichloronaphthalene 1,2-dichloronaphthalene 1,8-dichloronaphthalene trichloronaphthalene (1 isomer) tetrachloronaphthalene (8 isomers) pentachloronaphthalene (6 isomers) hexachloronaphthalene (6 isomers) heptachloronaphthalene (1 isomer) pentachloroanisol 2,4-dichlorobenzaldehyde 2,4-dichlorobenzoic acid
+ + + + + + + + +
+
+ + + + + +
+ +
+
+ + + + + +
+ + + + + + + +
+ + + + + +
+
+
+
+
+
+ + + + + + + + + +
+ + + + + + +
+ + + + + + + + +
+
+
+
+
+ + +
+
+ +
+ + +
+
+
+ + + + + +
+ + + + +
T2b
T5
T6
bromobenzene dibromobenzene (1 isomer) tetrabromobenzene (1 isomer) pentabromobenzene (1 isomer) dibromotrichlorotoluene tribromodichlorotoluene tetrabromochlorotoluene pentabromotoluene 2-bromonaphthalene 1-bromonaphthalene dibromonaphthalene (2 isomers) 2,4,6-tribromoaniline 4,4’-dibromobenzophenone
+
+
+ (+) +
+ + + +
Halogenated Pesticides
+ + + +
+ + +
+ +
+ +
+ + +
+ +
+ + + + + + + + + + + +
+ + +
+ + +
+ + + +
+ +
+ + + + + + + + + + + + + +
+ + + +
+ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
+ + + + + + + + + +
+ + + + + +
+ + + + + + + + + +
+
+
+
+ + + + + + +
+ + + + + + + + +
+
Brominated Arenes
R-hexachlorocyclohexane (R-HCH) β-hexachlorocyclohexane (β-HCH) γ-hexachlorocyclohexane (γ-HCH) δ-hexachlorocyclohexane (δ-HCH) 2,4’-DDMU 4,4’-DDMU 2,4’-DDE 4,4’-DDE 2,4’-DDMS 4,4’-DDMS 2,4’-DDD 4,4’-DDD 2,4’-DDT 4,4’-DDT 4,4’-DDA-methyl ester 2,4’-DDCN 4,4’-DDCN 2,4’-dichlorobenzophenone 4,4’-dichlorobenzophenone 1-(2-chlorophenyl)-1-(4-chlorophenyl)ethene 1,1-bis(4-chlorophenyl)ethene
T1
Nieder- Pichels- Spree, Dahme Da¨ me- Spandauer Spandauer Teltow Teltow Canal, Mach- Griebneuen- dorfer km ritzSchiffSchiffCanal, km 2.5, core nower nitzdorfer Gmu¨ nd 145 see fahrtskanal, fahrtskanal, km 3 0.35-0.40 m See see See km 0.6 km 2.1 depth 10.3 15.1 8.2 13.8 14.7 9.2 9.3 7.1 10.7 4.3 7.5
+ + + + + + + +
+ +
+ + +
+ + +
+ +
+ +
+ + +
+ + +
+ +
+ +
+ +
+
+ + + + + + + + + + +
+ + + + + + + + + + + + + + + + + + + +
+ + + + + + + + + + + + + +
+
+
+ + + + +
+ + + +
+ + + +
+ + + +
+ + +
+ + +
+ + +
+ + +
+ + + +
+ + + +
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TABLE 1 (Continued) sample code (Figure 1)
H3
H6
S2
S9
S10
S13
S14
Halogenated Pesticides 2,4’-methoxychlor 4,4’-methoxychlor 2,4’-MDE 4,4’-MDE 2,4’-MDD 4,4’-MDD 4,4’-dimethoxybenzophenone chlorfensone bromopropylate 1,1-bis(4-bromophenyl)acetic acid isopropylester a
+ +
T1
T2b
T5
T6
+ + + +
+ + + + + + + + + +
+ +
+ +
+
+
+ + + +
+ +
(+) ) not all isomers detected.
SE mass spectrometer (VG Analytical Ltd., Manchester, U.K.) linked to an HP 5890 gas chromatograph (Hewlett-Packard, Palo Alto, U.S.A.) which was equipped with a 50 m × 0.25 mm i.d. × 0.25 µm film BPX5 fused silica capillary column (SGE GmbH, Weiterstadt, D). Chromatographic conditions were as follows: 1 µL on-column injection at 50 °C, 3 min hold, then programmed at 3°/min to 300 °C, helium carrier gas velocity 40 cm/s. The mass spectrometer was operated at 1000 resolution in electron impact ionization mode (EI+, 70 eV) with a source temperature of 200 °C and scanned from 500 to 35 amu at a scan speed of 1 s/decade with an interscan time of 0.2 s. Quantitative GC/MS analysis was carried out with a quadrupole mass spectrometer HP 5985 linked to an HP 5890 gas chromatograph (Hewlett-Packard, Palo Alto, USA). For chromatographic separation a 30 m × 0.28 mm i.d. × 25 µm film MXT-5 fused silica lined steel capillary column (SGE GmbH, Weiterstadt, FRG) was used under the conditions described above. The target compounds were detected by single ion monitoring (SIM) of two ions in each of their most abundant ion clusters. An external four-point-calibration generated by a mixture of reference compounds was used for quantification. Detection limits (signal/noise > 3/1 in real samples) were in the range of 0.1 µg/kg dry matter; no attempts were made to quantify components with concentrations of less than 1 µg/kg dry matter. For quality assurance procedural blanks and reference samples (NIST Standard Reference Material 1941) were processed in the same manner as environmental samples. In the blanks no pesticides or PCBs were detected (detection limit 20 pg/µL per injection at a signal/noise ratio of 2.5/1). The results for the NIST reference material (n ) 6) were within 85-105% of the certified values. Identification of Compounds. Identification of individual compounds was based on comparisons of EI spectra and chromatographic retention times with those of authentic reference compounds purchased from Promochem (Wesel, FRG), Aldrich (Deisenhofen, FRG), and Merck (Darmstadt, FRG). Reference substances not commercially available were synthesized for identification as well as for quantification as follows. Brominated Chlorotoluenes. Isomer specific synthesis of brominated chlorotoluenes was performed via bromination of the corresponding mono- or dichlorinated toluenes by addition of dibromoisocyanuric acid in concentrated sulfuric acid. Individual isomers synthesized were 2,3,4,5-tetrabromo6-chlorotoluene, 2,3,4,6-tetrabromo-5-chlorotoluene, 2,3,5,6tetrabromo-4-chlorotoluene, 2,3,5-tribromo-4,6-dichlorotoluene, and 3,4,5-tribromo-2,6-dichlorotoluene. Bis(4-bromophenyl)acetic Acid Isopropylester. This compound could be obtained by reduction of bromopropylate with triethylsilane in trifluoroacetic acid according to Kursanov et al. (13). 4018
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Results and Discussion GC/MS screening analyses of lipophilic organic contaminants were applied to sediment samples of Havel and Spree rivers in the urban area of Berlin (H3, H6, S2, S9, S10, S13, S14, T1, T2b, T5, T6). Only sampling location S2 was situated approximately 100 km upstream of Berlin near Spremberg (Figure 1). In Table 1 the halogenated compounds identified are listed and attributed to the sampling locations. Molecular structures of selected contaminants are given in Figure 2. In addition to the groups of congeners of chlorinated and brominated aromatics various halogenated pesticides and corresponding metabolites were identified and partially quantified. Quantitative data of tri- to hexachlorinated benzenes, mono- and disubstituted bromo- and chloronaphthalenes, chlorinated bromotoluenes, DDT and its main metabolites (1,1-bis(chlorodiphenyl)-2,2-dichloroethane DDD, 1,1-bis(chlorodiphenyl)-2,2-dichloroethene DDE, 2,2-bis(chlorodiphenyl)acetonitrile DDCN, 1,1-bis(chlorodiphenyl)2-chloroethene DDMU, 2,2-bis(chlorodiphenyl)-1-chloroethane DDMS), pentachloroanisol, 2,4,6-tribromoaniline, and 4,4’-dibromobenzophenone as well as the pesticides chlorfensone, methoxychlor, and bromopropylate are presented in Table 2. For a second more comprehensive set of samples (S1, S3-8, S11-12, H1, H2a, H4, H5, H7-9, T1-4) selected groups of organic pollutants were determined. The selection of the compounds was based on the results of screening analyses. Quantitative analysis included tetra- to hexachlorinated benzenes, PCB, hexachlorocyclohexanes (R-, β-, γ-, δ-isomers), and DDT and its metabolites DDD, DDE, DDMS. The results are given separately for Havel river, Spree river, and Teltow Canal samples in Tables 3-5. Chlorinated Compounds. Chlorinated Benzenes and Styrenes. Chlorinated benzenes are well-known organic pollutants (14). Dichloro- and trichorobenzenes are used as starting material for the manufacturing of many technical products including antiseptic agents, solvents, and additives. Apart from hexachlorobenzene, a formerly used herbicide and a known byproduct in a number of organic syntheses, technical applications, and emission sources of higher chlorinated benzenes are insignificant (15). Chlorinated benzenes were identified in almost all sediment samples (Table 1). The concentrations of tetra- to hexachlorinated benzenes in sediments of the Spree river (Tables 2 and 4 ) ranged between the detection limit and 44 µg/kg. In sediment samples of the Havel river (Tables 2 and 3) and the Teltow Canal (Tables 2 and 5) mostly low concentrations up to 47 µg/kg were detected as well, but two of the Havel river samples, H9 and H2, contained higher concentrations of 140 and 430 µg/kg. The widespread and uniform distribution of PCB on a low concentration level in Havel and Spree sediments reflected nonpoint source emissions.
FIGURE 2. Organic halogen compounds identified in Havel and Spree river sediments. On the contrary, the isolated appearance of mono- to heptachlorinated styrenes in the sediment sample T1 indicated the contribution of a local emission source at the Teltow Canal. In addition, octachlorostyrene was identified at a sampling location nearby (T2). The sources of chlorostyrenes discharged into the aquatic environment have been attributed to technical operations such as magnesium production or thermolysis of chlorine containing organic matter (16-18). Polychlorinated Biphenyls, PCB. The almost ubiquitous distribution as well as sources and fate of polychlorinated biphenyls (PCB) in the aquatic environment are well investigated (e.g. refs 19-21). In nearly all sediments of the Havel
and Spree rivers PCB were identified (Tables 2-5 ). According to Baker et al. and Alcock et al. (22, 23) the quantitative analyses included only selected congeners, which represent the major portion in technical mixtures and environmental samples. Sediment samples of the Havel river were contaminated with PCB in a concentration range between 400 and 3400 µg/kg. A similar level of contamination was observed for the Spree and Teltow Canal sediments with concentrations up to 2600 µg/kg and 3400 µg/kg, respectively. Only in a few Spree river samples (S1, S4, S7) the concentrations fell below the detection limit. The maximum concentration of individual VOL. 35, NO. 20, 2001 / ENVIRONMENTAL SCIENCE & TECHNOLOGY
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TABLE 2. Concentrations of Halogenated Compounds in Selected Sediment Samples of Havel and Spree Rivers (µg/kg Dry Matter) sample code (Figure 1)
H3
H6
1,3,5-trichlorobenzene 1,2,4-trichlorobenzene 1,2,3-trichlorobenzene 1,2,3,5-/1,2,4,5-tetrachlorobenzene 1,2,3,4-tetrachlorobenzene pentachlorobenzene hexachlorobenzene sum of chlorinated benzenes 2-chloronaphthalene 1-chloronaphthalene 1,3-dichloronaphthalene 1,4-dichloronaphthalene 1,5/1,6-dichloronaphthalene 1,7/2,6/2,7-dichloronaphthalene 1,2-dichloronaphthalene 1,8-dichloronaphthalene sum of chlorinated naphthalenes pentachloroanisol
