Paul R. Becket ... Cambridge Isotopes (Andover, MA) while additional PCB congeners and chlorinated ... Globicephala melaena, at Hyannis, Cape Cod, MA.
Chemosphere,Vol. 33. No. 7, pp. 1369-1390, 1996
Pergamon PlI: S0045-6535(96)00272-X
Publishedby ElsevierScienceLid Printedin GreatBritain 0045-6535/96 $15.00+0.00
INTERLABORATORY COMPARISON STUDY FOR PCB CONGENERS AND CHLORINATED PESTICIDES IN BELUGA WHALE BLUBBER
Michele M, Schantz', Barbara J. Porter, and Stephen A. Wise Analytical Chemistry Division, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
Mark Segstro and Derek C. G. Muir Department of Fisheries and Oceans Canada, Freshwater Institute, Winnipeg, Manitoba, R3T 2N6, Canada
Stephanie Mossner and Karlheinz Ballschmiter Department of Analytical and Environmental Chemistry, University of UIm, Albert-Einstein-Alice I 1, D-89081 UIm, Germany
Paul R. Becket Analytical Chemistry Division, National Institute of Standards and Technology, Charleston, SC 29412 Receivedin USA 26 March 1996;acceptedIt July 1996)
ABSTRACT Three laboratories parttcipated in an interlaboratory comparison exercise for the determination of polychlorinated biphenyl (PCB) congeners and chlorinated pesticides in Standard Reference Material (SRM) 1588 (Organics in Cod Liver Oil) a whale blubber control material, and six beluga whale (Delphinapterus
leucas) blubber samples. The results are generally in good agreement. The minor disagreement of some of the results may be attributed to differences in detector calibrations, differences in chromatographic separation selectivity for specific compounds, or both The SRM and control material help to validate the analytical procedures and to verify that these procedures remain in controL. Published by Elsevier Science Ltd
1369
1370 INTRODUCTION In 1987, the Minerals Management Service, Lr S Department of the Interior, provided funds to the National Institute of Standards and Technology (NIST) and the National Oceanic and Atmospheric Administration (NOAA) tbr establishing the Alaska Marine Mammal Tissue Archival Project (AMMTAP) to provide a repository of tnarine mammal tissues for thture contaminant analyses. The background and goals of the AMMTAP have been described in detail in previous publications [1-5] As part of AMMTAP, NIST analyzes approximately 20-30% of the specimens for inorganic and organic constituents to provide accurate baseline data for: (1) evaluating the stability of tissue specimens during long-term storage, (2) providing some real-time measure of contaminant concentrations for monitoring purposes, (3) comparing with results from specimens collected in the future for long-term trend monitoring, and (4) comparing with analytical results from other laboratories on similar samples collected at the same time for real time monitoring. Subsamples of specimens from the bank are often provided t~ other research laboratories for analyses as part of the AMMTAP or for other studies of marine mammals
In 1992 subsamples of beluga whale
(Dell)htnat)lerus
leucas) blubber were distributed to two other laboratories for chemical analyses: (I) the Department of Fisheries and Oceans (DFO) in Winnipeg, Canada and (2) the Department of Analytical and Environmental Chemistry at the University of Uhn in Uhn, Germany
Subsamples of all of the AMMTAP beluga whale
blubber specimens are routinely provided to the DFO for analysis to expand their database on this species from eastern Canada through Alaska To insure that all of the analytical results for polychlorinated biphenyl (PCB) congeners and chlorinated pesticides in the AMMTAP database are comparable, an interlaboratory comparison exercise was conducted among NIST, DFO, and the University of Uhn Each of the three laboratories analyzed blubber subsamples from 4-6 beluga whales, a pilot whale blubber control material, and Standard Reference Material (SRM) 1588, Organics in Cod Liver Oil. The control material and SRM were used to validate analytical procedures and to monitor these procedures to verify that they remain in control Because some of the results were obtanied as part of routine analyses of the samples within the AMMTAP, there are not always replicate analyses of the samples. The results of this three laboratory intercomparison exercise are reported in this paper.
EXPERIMENTAL SECTION Materials. Several N1ST Standard Reference Materials (SRMs) were used as calibration solutions or as control samples during the analysis of the marine mammal tissues. SRM 2261, Chlorinated Pesticides in Hexane (Nominal Concentration 2 ~g/mL): SRM 2262, Chlorinated Biphenyl Congeners in 2,2,4trimethylpentane (Nominal Concentration 2 p.g/mLL and SRM 1588, Organics in Cod Liver Oil, were obtained from the Standard Reference Materials Program, NIST
Perdeuterated 4,4'-DDT was obtained from
Cambridge Isotopes (Andover, MA) while additional PCB congeners and chlorinated pesticides were obtained
1371 from AccuStandard (New Haven, CT) and Ultra Scientific (New Kingston, RI). All solvents were HPLCgrade. Samoles. Samples of blubber were collected from beluga whales taken in subsistence hunts by Alaskan natives at Point Hope in May 1989 (sample identification numbers: MM3B071 and MM3B074) and at Point Lay in July 1990 (sample identification numbers: MM4B 133, MM4B 136, MM4B 148, and MM4B 151 ) both on the Chukchi Sea coast of Alaska. Sampling was conducted using the standard AMMTAP protocol [2]. Characteristics of the animals including age, sex, morphometric measurements, time and location of sampling, and any observations made during sampling are provided in the AMMTAP inventory [6]. In December 1990 approximately 2 kg of blubber was collected using similar sampling protocols from stranded pilot whales,
Globicephala melaena, at Hyannis, Cape Cod, MA. This blubber was used to prepare a tissue homogenate for use as an analytical control material [7]. The tissue samples to be analyzed were homogenized using a cryogenic grinding procedure designed tO reduce the likelihood of changes in sample composition due to thawing and refreezing [8]. The sample homogenate, a frozen powder, was then divided into subsamples of approximately 6-8 g and stored in Teflon jars prior to analysis. For the intercomparison exercise all three laboratories analyzed SRM 1588, Organics in Cod Liver Oil (Table 1), the whale blubber control material (Table 2), and four beluga whale blubber samples (Tables 3, 4, and 5). Two of the laboratories, N1ST and DFO, analyzed two additional beluga whale blubber samples (Table 6). Determination ofPCB Con~eners and Chlorinated Pesticides. Measurements for the determination of PCB congeners and chlorinated pesticides were performed at N1ST (Gaithersburg, MD, USA), Department of Fisheries and Oceans (Winnipeg, Manitoba, Canada), and University of Ulm (UIm, Germany). The three laboratories used SRM 2261, SRM 2262, and two additional solutions containing 11 PCB congeners and 4 pesticides to prepare calibration solutions The methodology used at NIST tbr the analysis of the blubber samples has been described previously [3,7,9]. Briefly, 2 g to 3 g of the blubber homogenate were mixed with approximately 100 g of pre-extracted sodium sulfate. These mixtures were spiked with an internal standard solution containing perdeuterated 4,4'DDT, PCB 103, and PCB 198, and Soxhlet extracted for 18 h using methylene chloride. The extracts were concentrated to approximately I mL which was used for size exclusion chromatography (SEC) to remove the majority of the lipid and biogenic material. Following the SEC step, normal-phase liquid chromatography (LC) on a semi-preparative-scale aminopropylsilane column was used to isolate two fractions containing: (1) the PCB congeners and lower polarity chlorinated pesticides and (2) the more polar chlorinated pesticides. The extracts were analyzed by capillary gas chromatography with electron capture detection (GC-ECD) using a 60 m x 0.25 mm i.d., 0.25 /am film thickness, 5% phenylmethylpolysiloxane capillary column with
PCB PCB PCB PCB PCB PCB PCB PCB PCB PCB PCB PCB PCB PCB PCB PCB PCB PCB PCB PCB PCB PCB PCB PCB PCB PCB PCB PCB PCB
18 28 31 44 49 52 66 87 95 99 101 105 110 I 18 128 138 149 151 153 156 170 180 183 187 194 195 201 206 209
Compound
Table 1.
(Decachlorobiphenyl)
(2,2',3,3', 4,4',5,5',6-Nonachlorobiphenyl)
(2,2'.5-Trichlorobiphenyl) (2,4,4'-Trichlorobiphenyl) (2.4'. 5-Trichlorobiphenyl) (2,2'.3.5'-Tetrachlorobiphenyl) (2,2',4,5'-Tetrachlorobiphenyl) (2.2'. 5,5'-Tetrachl orobiphenyl) (2.3',4,4'-Tetrachlorobiphenyl) (2,2',3,4,5'-Pentachlorobiphenyl) (2,2',3,5',6-Pentachlorobiphenyl) (2.2',4,4', 5-Pentachlorobiphenyt ) (2,2'.4,5,5'-Pentachlorobiphenyl) (2,3,3',4,4'- Pentachlorobiphenyl ) ( 2,3,3',4',6-Pentachlorobiphenyl ) (2,3 ',4,4',5-Pentachlorobiphenyl ) (2,2',3,3',4,4'-Hexachlorobiphenyl ~ (2,2',3,4,4',5'-Hexachlorobiphenyl)' (2,2',3,4',5',6-Hexachlorobiphenyl) (2,2',3,5,5',6-Hexachlorobiphenyl) (2,2',4,4',5,5'-Hexachlorobiphenyl) (2,3,3',4,4',5-Hexachlorobiphenyl) (2,2',3,3',4,4',5-Heptachlorobiphenyl) ( 2,2', 3,4,4', 5,5'-Heptachlorobi phenyl ) (2,2',3,4,4',5',6-Hept achlorobiphenyl) (2,2',3,4',5,5',6-Heptachlorobiphenyl) (2,2',3,3',4,4', 5,5'-Octachlorobiphenyl) (2,2',3,Y,4,4', 5,6-Octachlorobiphenyl) (2,2',3,Y,4,5',6,6'-Octachlorobiphenyl) 45 + 5 107 d:4
276 ± 40
261 ± 29
129 ~ 5
127 60 2 75 8 176 47 ! 263 105 55 2 277 273 46.4 106 308 35 3 157
