Sweeper cove (harbor) and from Kuluk Bay (outside the harbor). Halibut and cod from inside were caught between 120 and 150 ft., and the aliquots (muscle and ...
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GENERAL PAPERS Organized by M.L. Trehy Symposia Papers Presented Before the Division of Environmental Chemistry American Chemical Society San Diego, CA April 1-5, 2001
DETERMINATION OF ORGANOCHLORINE POPS IN PACIFIC HALIBUTAND COD LIVER WITH SPE, NP-HPLC AND HRGC-ECD/MSD M.W. Arend*, W.M. Jarman+, and K. Ballschmiter* *Department of Analytical and Environmental Chemistry, University of Ulm, D-89069 Ulm, Germany + Energy and Geoscience Institute, Department of Civil and Environmental Engineering, University of Utah, 84108 Salt Lake City, UT
Introduction The polychlorinated biphenyls (PCB) constitute a group of 209 congeners. Because of their multi-purpose applications they were produced in high amounts in various well-defined technical mixtures over decades2,3; as contaminants they are globally distributed. As part of the group of persistent organic pollutants (POPs)4 they tend to biomagnify due to their lipophilicity5. Previous studies6,7,8 have shown that fish, particularly fish livers and the extracted oil (e.g., cod liver oil), can be used as a versatile and well defined tool for biomonitoring levels of PCBs and pesticides in aquatic environments. A successful trace analysis of organochlorines in biota relies on an effective clean-up step. In order to analyze less contaminated samples with PCB contamination levels below 1 µg/kg lipid (1ppb) a sample preparation method has been developed based on sample extraction with acetonitrile, solid-phase-extraction (SPE), normal-phase HPLC, and HRGC/ECD/MSD9. The HPLC backflush technique can be effectively used for group separation of POPs and reduces the amount of solvents needed. Analyzing halibut (livers and muscles) and cod (livers) samples from the Northern Pacific (Aleutian Islands) we show the enrichment of PCBs and organochlorine pesticides in these remote areas and compare patterns and levels.
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Figure 1. Map of the Northern Pacific Ocean with the Aleutian Chain
Experimental Section All fish samples were caught in August 1999 at Adak Island (except one sample from Attu island) (Fig. 1), using the long-line-method. The Adak samples were collected from Sweeper cove (harbor) and from Kuluk Bay (outside the harbor). Halibut and cod from inside were caught between 120 and 150 ft., and the aliquots (muscle and liver) of the fish were store in pre-clean jars and frozen at –20ºC. The Attu halibut sample was purchased from Adak Seafoods, LLC in order to compare the levels with those of the Adak samples. During World War II until 1997 there was a US naval base located on Adak Island. High levels of PCBs have been reported from Adak and Amchitka island10.
For analysis approximately 5-10 g of fish liver and 20 –30 g of muscle samples were homogenized in a grinder with anhydrous sodium sulfate and quartz sand, then cold extracted in a glass column with 100 mL of acetonitrile; a second extraction fraction followed with 150 mL of acetone. Both extracts were evaporated for lipid-determination; only the acetonitrile fraction was used for further clean up procedure and analysis. Sample preparation and quantification included solid-phase-extraction (SPE) on LiChrolut® EN polymer sorbent for environmental analysis from Merck, group separation with normal-phase-HPLC-backflush technique on an aminopropylsiloxane column, followed by HRGC on a CP SIL 19 capillary column (60 m*0.25 mm 0.25µm) with electron-capture-detection (ECD). Details were recently described in reference 9. HRGC/EI-MS (electron impact mass spectrometry) on a HP 6890 (GC) with a HP 5973N quadrupole mass selective detector (MSD) in the selective ion monitoring mode (SIM) on a J&W DB5 MS capillary column (60m*0.32mm*0.25µm) was used for confirming qualitative and quantitative determination.
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4,4'DDE
HCB
153
138
180
trans Nona Ua cis CD
170 α-HCH A 33
149 118
2,4'-DDE 101 IS TCN IS 103
PCBz
99
146 105
110
187 128
199
183
28 52
10
194 195
20
206 205
209
PBDE 47
151 0
203/196
171 193
30
40
50
m in
Figure 2. HRGC (SIL 19)-ECD chromatogram of the PCB-fraction isolated by a back flush technique from liver of pacific halibut caught outside the harbor of Adak.
Results Table 1 gives the PCB concentrations obtained for the Cod and Halibut samples (liver and muscle) from Adak and Attu Island. All concentrations are reported as micrograms per kilogram (µg/kg) of the lipid weight (ppb). S (7 PCB) is the sum of the concentrations of the seven indicator congeners (PCB 28, 52, 101, 118, 138, 153 and 180). Table 1. Quantification (ECD) of seven indicator PCBs in fish samples (liver and muscle) Concentration [µg/kg lipid] PCB No.
Cl-Substitution
28
Cod liver (Sweeper Cove)
Cod liver (Kuluk Bay)
Halibut liver (Kuluk Bay)
Halibut muscle Kuluk Bay
Halibut muscle (Attu)
2,4,4´
19,3
3,1
1,9
0,4
0,9
52
2,2´,5,5´
43,8
7,1
4,7
1,8
3,3
101
2,2´,4,5,5´
129
26,5
10,8
6,6
5,6
118
2,3´,4,4´,5
149
28,5
12,1
6,8
2,6
138
2,2´,3,4,4´,5´
262
82,3
36,5
25,1
5,4
153
2,2´,4,4´,5,5´
349
103
46,8
34,8
5,9
111
41,5
22,9
15,1
1,7
4252
1166
543
362
102
180
2,2´,3,4,4´,5,5´
Σ (7 PCB) · 4
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Table 2.Quantification (MSD) of Organochlorines in fish liver Concentration [µg/kg lipid] Compound
Cod liver (Sweeper Cove)
Cod liver (Kuluk Bay)
Halibut liver (Kuluk Bay)
HCB
43,2
11,3
12,3
α-HCH
11,9
7,4
4,3
β-HCH
6,7
1,6
1,7
γ-HCH
5,1
1,3
0,8
cis/trans CD
219
5,0
12,2
PCBz
1,4
0,8
1,4
2,4´-DDE
2,5
0,1
2,0
4,4´-DDE
882
52,5
41,6
2,4´-DDD
8,8
2,0
0,5
4,4´-DDD
179
n.q.a
3,1
2,4´-DDT
13,3
13,0
8,7
4,4´-DDT
8,7
n.q.a
4,6
Σ (3 HCH)
23.7
10,3
6,8
Σ (6 DDT)
1094
68
61
a
not quantitated To estimate the total PCB concentration the seven indicator congeners Σ (7 PCB) were multiplied by a factor of four.
All Adak samples show relatively high levels of PCB contamination and a typical biological PCB pattern of a higher chlorinated technical mixture (Fig. 2.). Total PCBconcentrations determined in the cod- and halibut- liver samples from Kuluk Bay, 543 µg/kg and 1166 µg/kg (lipid basis), respectively, compared with 4252 µg/kg (lipid basis) for Sweeper Cove are different by a factor of about four to eight. The cod liver sample from Sweeper Cove indicates a high organochlorine exposure in the harbor; however, this may be related to inter-species comparison. Comparing the Halibut muscle
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samples from Kuluk Bay and near Attu Island, total PCB levels differ by factor of three, which may indicate higher contamination in Kuluk Bay then at the Attu site. The levels of organochlorine pesticides in liver samples from Adak are summarized in Table 2. Total DDT concentration Σ (6 DDT) are calculated from the sum of 2,4‘-DDT, 4,4‘-DDT, 2,4‘-DDD, 4,4‘-DDD, 2,4‘-DDE and 4,4‘-DDE. Three HCH isomers (α-HCH, β-HCH and γ-HCH) were calculated to estimate the total Lindane concentration Σ (3 HCH). Additionally, the levels of hexachlorobenzene (HCB), pentachlorobenzene (PCBz) and cis/trans chlordane (CD) were determined in three liver samples from Adak Island. Similar to the PCB contamination, the cod liver sample from Sweeper Cove shows highest organochlorine pesticide levels with surprisingly high concentrations of a-HCH and HCB. Total DDT concentration in the Sweeper Cove sample is about 16-times higher than values from Kuluk Bay. The relative proportions of the DDT compounds and cis/trans chlordane in all three liver samples from Adak are similar. Congeners of polybrominated biphenyl ethers (PBDE) used as flame retardant were observed in all samples from Adak (tetra- and penta-bromo substitution). Conclusions The results support the occurrence of high organochlorine levels at some hot spots in the Northern Pacific Ocean probably related to past military activity. Continuing input of POPs from some point sources into the sea will continue and could effect fish and marine mammals. References 1. Ballschmiter K, Zell M (1980) Fresenius Z Anal Chem 302: 20-31 2. Erickson MD (1997) Analytical Chemistry of PCBs, CRC Press, 2nd. ed.: pp. 688-1415 3. Ballschmiter K (1988) in Fresenius W, Günzler H, Huber W (eds.), Analytiker Taschenbuch, Volume 7 Springer, Berlin: pp. 393-432 4. Ballschmiter K (1996) Pure & Appl. Chem 68, 9: 177-1780 5. Muir DCG, Norstrom RJ, Simon M (1988) Environ Sci Technol 22: 1071-1079 6. Ballschmiter, K.; Buchert, H.; Bihler, S.; Zell, M. (1981) Fresenius J. Anal. Chem. 306, 323-339 7. Froescheis, O.; Looser, R.; Cailliet, G. M.; Jarman, W.M.; Ballschmiter, K. Chemosphere (2000) 40, 651-660 8. Schantz MM, Parris RM, Kurz J, Ballschmiter K, Wise SA (1993) Fresenius J Anal Chem 346: 766-778 9. Arend, M. W.; Ballschmiter, K. Fresenius J Anal Chem 2000, 366, 324-328 10. Estes JA, Bacon CE, Jarman W, Norstrom RJ, Anthony RG, Miles AK (1997) Marine Pollution Bulletin Vol. 34, No 6 : pp. 486-490
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