Compounds Of Technical Toxaphene Research Articles

Evidence for cometabolic transformation of weathered toxaphene under aerobic conditions using camphor as a co-substrate.

Toxaphene is a persistent organic pollutant, composed of approximately 1000 highly chlorinated bicyclic terpenes. The purpose of this study was to evaluate if camphor, a structural analogue of toxaphene, could stimulate aerobic biotransformation of weathered toxaphene. Two enrichment cultures that degrade camphor as the sole carbon source were established from contaminated soil and biosolids. These cultures were used to evaluate aerobic transformation of weathered toxaphene. Only the biosolids culture could transform compounds of technical toxaphene (CTTs) in the presence of camphor, while no transformation was observed in the presence of glucose or with toxaphene as a sole carbon source. The transformed toxaphene had lower concentration of CTTs with longer retention times, and higher concentration of compounds with lower retention times. Gas chromatography with electron capture negative ion mass spectrometry (GC/ECNI-MS) showed that aerobic biotransformation mainly occurred with Cl8 - and Cl9 -CTTs compounds. The patterns of Cl6 - and Cl7 -CTTs were also simplified albeit to a much lesser extent. Seven camphor-degrading bacteria were isolated from the enrichment culture but none of them could degrade toxaphene. Camphor degrading culture can aerobically transform CCTs via reductive pathway probably by co-metabolism using camphor as a co-substrate. Since camphor is naturally produced by different plants, this study suggests that stimulation of aerobic transformation of toxaphene may occur in nature. Moreover plants, which produce camphor or similar compounds, might be used in bioremediation of contaminated soils.

Analysis and Characterization of Polychlorinated Hydroxybornanes as Metabolites of Toxaphene Using a Polar Bear Model.

Abiotic and biotic transformation of toxaphene (camphechlor) results in the selective enrichment of recalcitrant congeners while other, less persistent compounds of technical toxaphene (CTTs) are degraded. Until now, there has been little knowledge on oxidation transformation of toxaphene. For instance, the existence of hydroxylated CTTs (OH-CTTs) in authentic environmental and food samples has not been proven. For this reason, we synthesized a mixture consisting of tetra- to heptachlorinated OH-CTTs and simplified it by countercurrent chromatography (CCC). Thus, 227 OH-CTTs were detected in the CCC fractions (12 tetra-, 117 penta-, 81 hexa-, and 17 heptachlorinated OH-CTTs), which was >50% more than detected before the fractionation. One CCC fraction consisting of only 18 OH-CTTs was used to develop a sample cleanup method which aimed to remove CTTs, isobaric PCBs, and sample matrix. The final cleanup procedure consisted of (i) gel permeation chromatography (GPC) and adsorption chromatography using (ii) deactivated and (iii) activated silica gel. Hence, up to 320 and 4350 μg/kg lipid weight of octa- and nonachlorinated CTTs were detected in four liver samples and adipose tissue of polar bears, respectively. Furthermore, the presence of one hexachlorinated OH-CTT isomer could be verified in the samples, which was about 1% of the octachlorinated CTTs determined in the liver samples.

Offline coupling of high-speed counter-current chromatography and gas chromatography/mass spectrometry generates a two-dimensional plot of toxaphene components

High-speed counter-current chromatography (HSCCC), a separation technique based solely on the partitioning of solutes between two immiscible liquid phases, was applied for the fractionation of technical toxaphene, an organochlorine pesticide which consists of a complex mixture of structurally closely related compounds. A solvent system ( n-hexane/methanol/water 34:24:1, v/v/v) was developed which allowed to separate compounds of technical toxaphene (CTTs) with excellent retention of the stationary phase ( S f = 88%). Subsequent analysis of all HSCCC fractions by gas chromatography coupled to electron-capture negative ion mass spectrometry (GC/ECNI-MS) provided a wealth of information regarding separation characteristics of HSCCC and the composition of technical toxaphene. The visualization of the large amount of data obtained from the offline two-dimensional HSCCC–GC/ECNI-MS experiment was facilitated by the creation of a two-dimensional (2D) contour plot. The contour plot not only provided an excellent overview of the HSCCC separation progress, it also illustrated the differences in selectivity between HSCCC and GC. The results of this proof-of-concept study showed that the 2D chromatographic approach involving HSCCC facilitated the separation of CTTs that coelute in unidimensional GC. Furthermore, the creation of 2D contour plots may provide a useful means of enhancing data visualization for other offline two-dimensional separations.

Anaerobic transformation of compounds of technical toxaphene. I. Regiospecific reaction of chlorobornanes with geminal chlorine atoms.

Technical toxaphene (Melipax) and the single compounds of technical toxaphene (CTTs) 2,2,5-endo,6-exo,8,8,9,10-octachlorobornane (B8-806), 2,2,5-endo,6-exo, 8,9,9,10-octachlorobornane (B8-809), 2,2,5,5,8,9,9,10,10-nonachlorobornane (B9-1025), 2-endo,3-exo,5-endo,6-exo,8,8,9,10,10-nonochlorobornane (B9-1679), 2-endo,3-exo,5-endo,6-exo,8,9,10,10-octachlorobornane (B8-1414), 2-endo,3-exo,5-endo,6-exo,8,8,9,10-octachlorobornane (B8-1412), and 2-exo,3-endo,5-exo,9,9,10,10-heptachlorobornane (B7-1453) were treated with suspensions of the anaerobic bacterium Dehalospirillum multivorans. After 7 d, more than 50% of technical toxaphene was transformed, and the relative amount of early eluting CTTs increased. After 16 d, only 2-exo,3-endo,6-exo, 8,9,10-hexachlorobornane (B6-923), 2-endo,3-exo,5-endo,6-exo, 8,9,10-heptachlorobornane (B7-1001), and a few minor penta- and hexachloro-CTTs were detected in the samples. The result of the transformation was comparable with observations in naturally contaminated sediments and soil. However, the performance with D. multivorans was more simple and reproducible, as well as faster, than use of soil, sediment, or anaerobic sewage sludge. In agreement with reports in the literature, reductive dechlorination at geminal chlorine atoms (gem-C1s) was found to be the major CTT transformation pathway. Experiments conducted with CTTs and gem-C1s at both primary and secondary carbons clarified that the initial C1 --> H substitution takes place at the secondary carbon C2. Furthermore, the 2-endo-C1 position was preferably substituted with hydrogen. In the case of B8-806, the dechlorination at the secondary carbon C2 was approximately 20-fold faster than the subsequent, slow reduction at the primary carbon C8. The three different formerly unknown heptachloro-CTTs, 2-exo,3-endo,6-exo,8,9,9,10-heptachlorobornane (B7-1473), 2-exo, 3-endo,6-endo,8,9,9,10-hepatchlorobornane (B7-1461), and 2-exo, 3-endo,6-exo,8,8,9,10-heptachlorobornane (B7-1470) were found as intermediates of the B8-806/809 transformation. Treatment of B9-1679 with D. multivorans indicated that gem-C1s on the bridge (C8 and C9) are dechlorinated faster than gem-C1s on the bridgehead (C10).

Distribution and levels of eight toxaphene congeners in different tissues of marine mammals, birds and cod livers

Levels and distribution of eight compounds of technical toxaphene (CTTs) were determined in different marine species (seals, cetaceans, birds, and fish). The eight CTTs included six commercially available and two chlorobornanes prepared in our lab. These congeners were present in all investigated samples. In agreement with earlier studies, the octachlorobornane B8-1413 (P-26) and the nonachlorobornane B9-1679 (P-50) were the most abundant congeners in most of the samples. In seal blubber, B8-1413 (P-26) and B9-1679 (P-50) contributed with up to ∼80% (Weddell seal) to the sum of the eight CTTs. In seals from the northern hemisphere the nonachlorobornane was more abundant while in those from the southern hemisphere (Antarctic and Namibia), the octachlorobornane B8-1413 (P-26) usually appeared at higher concentrations. Depending on the species the contribution of the other congeners varied significantly. B9-1025 (P-62) ranged from 2–20%, B8-1412 was found at 4–25% with highest contribution in birds, and B8-2229 (P-44) was found at 5–15%. The remaining three congeners B7-1453, B8-1414 (P- 40), and B8-1945 (P-41) were lower abundant except B8-1414 (P-40) which was found at high contribution in liver and kidney of birds. The sum of the eight CTTs ranged from 4 μg/kg to 1.4 mg/kg, depending on the species and region. In most of the seal blubber samples, PCBs and DDT were more abundant (factor 2–20) but Antarctic Weddell seals showed higher CTT levels than PCBs and DDT.

ENANTIOSELECTIVE FATE OF CHIRAL CHLORINATED HYDROCARBONS AND THEIR METABOLITES IN ENVIRONMENTAL SAMPLES

Gas chromatographic enantioseparation of chiral organochlorines (α-HCH, cis- and trans-chlordane, heptachlor, heptachlor epoxide, oxychlordane, o,p′-DDT, compounds of technical toxaphene, stable atropisomeric PCBs and methylsulfonyl-PCBs) has been achieved during the last decade. For this purpose chiral stationary phases based on cyclodextrin derivatives have been applied in combination with GC/ECD, GC/MS, MDGC, and MS/MS. With these techniques methods have been developed which have been used to study the enantioselective fate of the chiral organochlorines. Changes in the enantioratios and conclusions drawn are reviewed.

Production of toxaphene enantiomers by enantioselective HPLC after isolation of the compounds from an anaerobically degraded technical mixture.

Enantiomers of 12 chlorobornanes were separated on a chiral stationary HPLC phase. The investigated compounds included relevant chlorobornanes in technical toxaphene (Toxicant A and an unknown hepatachlorobornane), anaerobically mediated media such as sediment, soil, and sewage sludge (B6-923, B7-1001), as well as eight persistent compounds of technical toxaphene (CTTs) frequently detected in biological samples (B7-1000, B7-1453, B8-1412, B8-1413 or P-26, B8-1414 or P-40, B8-1945 or P-41, B8-2229 or P-44, and B9-1679 or P-50). Sufficient amounts of these 12 CTTs were not commercially available and had to be produced in our lab. Eight CTTs were obtained from sewage sludge that was spiked with technical toxaphene and kept under anaerobic conditions for four weeks. The samples were extracted with hexane followed by RP-HPLC fractionation. The resulting toxaphene pattern was significantly simpler than that of the technical mixture. CTTs that showed intense fragmentation in GC/ECNI-MS were preferably metabolized. Moreover, only one of the diastereomers that make Toxicant A (B8-806/B8-809 or P-42a/b) resisted degradation in sewage sludge. We found that the persistent component of Toxicant A is 2,2,5-endo,6-exo,8,9,9,10-octachlorobornane (B8-809 or P-42b). B9-1679 (P-50), B7-1453, and B8-1412 were earlier isolated from biological samples, and B7-1000 was isolated from naturally contaminated sediments. The fractions obtained after these procedures were suitable for enantioselective HPLC separations. The first eluting enantiomer was usually obtained as an enantiopure standard whereas the second eluting enantiomer also contained the other enantiomer. Attempts to determine the optical rotation with the help of a chiral HPLC detector failed. Elution orders of the enantiomers were established on three GC chiral stationary phases. Only the enantiomers of B7-1453 and B8-1945 (P-41) eluted in the same order from all CSPs while the others showed different enantiomer elution orders or were not resolved on one of the chiral GC stationary phases. The knowledge and consideration of these results is important for the interpretation of enantiomer ratios found in biological samples and comparison of literature data.

Liquid chromatographic profiles of individual compounds of technical toxaphene

The elution orders of 20 hexa- to nonachlorobornanes and five hexa- to octachlorocamphenes were studied with normal-phase silica and amino phase HPLC, reversed-phase HPLC, as well as gel-permeation chromatography (GPC). Twenty-one compounds of technical toxaphene (CTTs) are commercially available and four were isolated from environmental samples. Structure-activity relationships and chromatographic properties were deduced from the data sets derived on these LC systems. The retention on silica (low-resolution LC and HPLC) increased with the polarity of the CTTs. The elution order of CTTs on amino normal-phase HPLC was, for the most part, the same as on silica normal-phase HPLC. The degree of chlorination determined the elution order of CTTs on C 18 RP-HPLC. CTTs eluted from medium-pressure GPC with decreasing molecular size. Chlorobornanes with dichloro substituents on the six-membered ring eluted after the chlorobornanes without geminal chlorine atoms on secondary carbons, indicating that these congeners are larger. Altogether, the results increase the knowledge of complex substance class and may serve as a tool in order to gain further standard components.

Application of well-defined ?-cyclodextrins for the enantioseparation of compounds of technical toxaphene and further organochlorines

Enantioselective gas chromatography with 11 columns that contained different modified cyclodextrins was applied to chiral organochlorines. We initially investigated columns that contained pure heptakis(6-O-tert-butyldimethylsilyl-2,3-di-O-methyl)-β-cyclodextrin (β-TBDM) and six fractions resulting from liquid chromatographic separation of randomly silylated β-TBDM. Four β-TBDM fractions investigated with liquid chromatography–mass spectroscopy had an excess of 1–4 methyl groups instead of tert-butyldimethylsilyl groups. In contrast to randomly silylated β-TBDM (enantioseparation of all compounds except one), relatively few compounds (2–7 of 21 organochlorines) were enantioresolved on the fractionated chiral stationary phases. No fraction with high enantioselectivity for compounds of technical toxaphene (CTTs) was obtained. A second series of experiments evaluated columns coated with chemically bonded (CB) or polysiloxane-diluted (PD) permethyl-β-cyclodextrin (β-PMCD). Of the two, only CB-β-PMCD separated the enantiomers of CTTs and atropisomeric PCBs and not PD-β-PMCD. Additionally, a column coated with PD-γ-PMCD was tested. © 2000 John Wiley & Sons, Inc. J Micro Sep 12: 541–549, 2000

Levels of Organochlorines (DDT, PCBs, Toxaphene, Chlordane, Dieldrin, and HCHs) in Blubber of South African Fur Seals ( Arctocephalus pusillus pusillus) from Cape Cross/Namibia

Organochlorines (DDT, toxaphene, PCBs, chlordane, HCHs, dieldrin) were quantified in the blubber of eleven fur seals of the species Arctocephalus pusillus pusillus. The sample clean-up included microwave-assisted extraction (MAE), gel-permeation chromatography (GPC), adsorption chromatography on silica gel and quantitation with GC/ECD. Compounds of technical toxaphene (CTTs) were determined after separation from the PCBs. Highest levels arose for p, p′-DDE (7–1000 μg/kg). A so far unknown compound labelled Q1 caused the second most abundant peak in the samples. Q1 was identified as a heptachloro compound by GC/MS in the electron capture negative ionisation and electron impact ionisation mode. Levels of Q1 were estimated relative to the ECD response factor of trans-nonachlor. These estimated Q1 levels ranged from 27 to 351 μg/kg being in the range or higher than the levels of PCBs (6–697 μg/kg), toxaphene (10–97 μg/kg), chlordane (3–159 μg/kg), and dieldrin (4–36 μg/kg). One sample which showed significantly higher DDT and PCB levels (but not toxaphene, dieldrin, Q1, and chlordane) than the others is most likely migrated from an area higher polluted with DDT and PCBs. Another one showed very low levels which were not explained. Except these samples, the levels determined in the blubber were among the lower levels reported for this kind of tissue. The data also confirmed that the organochlorine levels in Africa are varying from region to region, and that there is still a need for further research.

Determination of Organochlorine Levels in Antarctic Skua and Penguin Eggs by Application of Combined Focused Open-Vessel Microwave-Assisted Extraction, Gel-Permeation Chromatography, Adsorption Chromatography, and GC/ECD

Levels of organochlorines (PCBs, DDT, toxaphene, chlordane, hexachlorobenzene (HCB), hexachlo-rocyclohexanes (HCHs), dieldrin, Q1) were determined in eggs of both penguins (Adelie Pygoscelis adeliae, Chinstrap Pygoscelis antarctica, Gentoo Pygoscelis papua) and skuas (South Polar Skua Catharacta maccormicki, Brown Skua Catharacta antarctica lonnbergi, Mixed Pair Skua Catharacta maccormicki x lonnbergi) from the Antarctic. Focused open-vessel microwave-assisted extraction (FOV-MAE) was performed for the extraction of entire, partly lyophilised eggs (approx. 50 g). After gel-permeation chromatography (GPC) and adsorption chromatography on deactivated silica gel, the quantitation was performed by GC/ECD on two capillary columns of different polarity. Compounds of technical toxaphene (CTTs) were determined after separation of the PCBs. The sample clean-up method was validated with certified reference material SRM 1588. In general, skua eggs revealed higher organochlorine levels than penguin eggs. Main contaminants in skua eggs were p,p'-DDE, PCB 153, and PCB 180 with levels about 10 − 350 μg/kg wet weight without shell (ww). Eggs of penguins were topped by levels of hexachlorobenzene (HCB) and p,p'-DDE (2 − 22 μg/kg ww), respectively. In skua eggs, the most abundant CTTs were B9-1679 (Parlar #50) > B8-1413 (Parlar #26) > B9-1025 (Parlar #62) > B8-1412, the levels were about 1-20 μg/kg ww. In penguin eggs, however, the order was B8-1413 (Parlar #26) > B9-1679 (Parlar #50) > B8-1412 > B9-1025 (Parlar #62), and the levels ranged from 0.02 − 0.8 μg/kg ww. A so far unknown heptachloro compound labelled Q1 caused an abundant peak in some samples. Levels of Q1 (2 − 126 μg/kg ww in skua eggs and 0.3 − 1.2 μg/kg ww without shell in penguin eggs) were estimated relative to the ECD response factor of trans-nonachlor.

Variety, structures, GC properties, and persistence of compounds of technical toxaphene (CTTs)

General limitations on the variety of chlorinated bornanes due to steric and energetic aspects are presented. The empirical rules were supported by spectroscopic and semiempirical calculations. It was found that a dichloromethyl substituent on C8 requires a 6- exo chlorine atom and a dichloromethyl group on C9 requires a 2- exo chlorine atom. The relevance of energetically optimal conformations on C8, C9, and C10 is discussed. It was shown that the different conformations are not relevant for the nomenclature of polychlorinated bornanes and that atropisomers are not likely to exist at physiological temperatures. On the other hand, the optimal conformers discussed earlier by Parlar seems to be one of the key factors that lead to persistence.

Enantioseparation of the compounds of technical toxaphene (CTTs) on 35% heptakis (6-O-tert-butyldimethylsilyl-2,3-di-O-Methyl)-β-cyclodextrin in OV1701

The separation of the enantiomers of the compounds of technical toxaphene (CTTs) on heptakis(6-O-tert-butyldimethylsilyl-2,3-di-O-methyl)-β-cyclodextrin (β-TBDM) has been studied by gas chromatography with electron-capture detection (GC-ECD). Enantiomers of eight of the nine CTTs under investigation were separated on this chiral stationary phase. Separations of the enantioners of CTTs have hitherto been achieved ontert-butyldimethylsilylated β-cyclodextrin (β-BSCD). The chiral resolution values and separation factors of the CTTs on β-TBDM have been compared with those obtained on β-BSCD. Although several components coeluted, enantioselective determination of three CTTs was possible in an extract of seal blubber. For each CTT the first-eluting enantiomer was enantioenriched. Enantioselective accumulation of2-endo, 3-exo,5-endo,6-exo,-8,8,9,10-octachlorobornane (B8-1412) in biota has been established for the first time.

Levels and Enantiomeric Ratios of Chlorinated Hydrocarbons in Livers of Artic Fox (Alopex Lagopus) and Adipose Tissue and Liver of a Polar Bear (Ursus Maritimus) Sampled in Iceland

Polychlorinated biphenyls (PCBs), oxychlordane, DDT and its metabolites, hexa-chlorobenzene (HCB), hexachlorocyclohexanes (HCHs), and compounds of technical toxaphene (CTTs) were quantified by gas chromatography and electron capture detection in livers of ten arctic foxes (Alopex lagopus) and in liver and adipose tissue of a polar bear (Ursus maritimus) sampled in Iceland. Enantiomeric ratios of oxychlordane and other chiral organochlorine were determined after gas chromatographic enantioseparation on two chiral stationary phases. The organochlorine pattern of the livers of arctic foxes was dominated by oxychlordane. The enantiomeric ratio of oxychlordane was >1 with the exception of the sample with the highest oxychlordane level. This result was confirmed by gas chromatography-mass spectrometry. PCB congeners and other organochlorines were only lowly abundant. PCB congeners were topped by PCB 180. The samples were from two independent populations, one feeding on the marine and the other feeding on the terrestrial food web. Levels of chlorinated hydrocarbons reflected the different food habits of the arctic foxes from coastal and inland habitats. Liver and adipose tissue of the polar bear showed deviating levels and ratios of the contaminants. Oxychlordane and p,p′-DDD were the only compounds found in greater abundance in liver than in adipose tissue. All other compounds were more abundant in adipose tissue. Enantiomeric ratios of oxychlordane, α-HCH, B8-1413 (Parlar #26), and B9-1679 (Parlar #50) were > 1 if the compounds were detected in the polar bear samples.

PCB/Toxaphene group separation on silica prior to congener specific determination of toxaphene residues in fish and other samples by GC/ECD

A precise quantification of toxaphene residues of environmental samples by gas chromatography/ electron capture detection (GC/ECD) requires the separation of the bulk of the polychlorinated biphenyls (PCBs) from the compounds of technical toxaphene (CTT) fraction. For this reason, a PCB/CTT group separation on silica was developed 88-1413 (Parlay #26) and B7-515 (Parlay #32) eluted as first and last out of ten important CTT standards, and can be used to determine the elution volume of the CTT fraction on silica. GC/ECD quantification of CTTs was possible after separation of PCBs on 8.0 g activated silica eluted with 48 mL n-hexane followed by quantitative elution of CTTs with n-hexane/toluene (65:35; v/v). This method is a compromise between separation efficiency and consumption of material. Finally, eight CTTs were quantified in cod liver samples from Iceland and the Baltic Sea.

Optimized pressure-pulse splitless injection and electron-capture, negative ionization detection for the congener specific determination of compounds of technical toxaphene

The goal of the study is the optimization of the congener specific determination of compounds of technical toxaphene (CTTs). For this reason GC/ECNI-MS and CTT standard mixtures are applied. The splitless injection is improved by pressure-pulse injection which yields significantly higher abundance of the CTTs than by the conventional constant flow injection technique. The abundance of low volatile CTTs like B9-1025 (Parlar #62) is increased by factor 3 or more. The pressure-pulse injection can easily be integrated in standard (constant flow splitless injection) methods without influencing the retention times and reproducibility. The GC oven program and the flow are optimized for the separation of CTTs on a non-polar CP-Sil 2 column. Problems caused by oxygen in the ion source are discussed.

Enantiomeric resolution of persistent compounds of technical toxaphene (CTTs) on t-butyldimethylsilylated β-cyclodextrin phases

Eight of the most important single compounds of technical toxaphene were separated on t-butyldimethylsilylated β-cyclodextrin (β-BSCD) diluted in a medium polar phase using gas chromatography with electron capture detectors (GC-ECD). The enantiomeric resolution of all compounds was obtained in one GC run. The β-BSCD phase also separated the enantiomers of oxychlordane, cis- and trans-chlordane as well as α-HCH. Problems in the enantioselective determination of CTTs in biological samples are discussed. Finally, the enantioselective determination of the two most recalcitrant CTTs in biological samples was achieved using electron capture negative ionization mass spectrometry (GC-ECNI-MS) in the single ion monitoring (SIM) mode.

Congener specific determination of compounds of technical toxaphene (CTTs) in different antarctic seal species

Gas chromatography and electron-capture, negative-ionization, mass spectrometry (GC-ECNI-MS) in combination with a non-polar stationary phase (CP-Sil 2) was applied to study the composition of residues of the multicomponent toxaphene mixture in seal blubber from the Antarctic. In samples of the five Antarctic seal species eleven compounds of technical toxaphene (CTTs) were detected and six of them quantified by application of single standard compounds. Five abundant CTTs in seal blubber were included in the “Parlar 22 components standard” (commercially available) and one further was isolated and quantified for the first time. Finally, high levels of toxaphene were determined in Weddell seals and crabeaters confirming that toxaphene is a major organochlorine pollutant in the Antarctic.

Congener-specific separation of compounds of technical toxaphene on a nonpolar CP-Sil 2 phase

Commercially available and persistent compounds of technical toxaphene (CTTs) were analyzed on a very nonpolar CP-Sil 2 capillary column. The bornane skeleton was divided into three parts: the six-membered ring (C1 (SINGLE BOND) C6), the substituents at the bridge (C8 and C9), and the substituents at the bridge head (C10). With two parts fixed, the influence of the third substructure on the relative retention indices (RRI) was investigated. Several substructures leading to low or high RRI values were observed. Furthermore, structural elements leading to low gas chromatographic or electron capture negative ionization response factors and influences of structure of CTTs on persistence in biota were recognized. Finally, first indications of the structure of unknown persistent CTTs are presented. © 1997 John Wiley & Sons, Inc. J Micro Sep 9: 29–36, 1997

P-43 Replication of hepatitis C virus in cloned human T cell lymphotropic virus type-I infected cell line (MT-2)

Levels and distribution of eight compounds of technical toxaphene (CTTs) were determined in different marine species (seals, cetaceans, birds, and fish). The eight CTTs included six commercially available and two chlorobornanes prepared in our lab. These congeners were present in all investigated samples. In agreement with earlier studies, the octachlorobornane B8-1413 (P-26) and the nonachlorobornane B9-1679 (P-50) were the most abundant congeners in most of the samples.In seal blubber, B8-1413 (P-26) and B9-1679 (P-50) contributed with up to ∼80% (Weddell seal) to the sum of the eight CTTs. In seals from the northern hemisphere the nonachlorobornane was more abundant while in those from the southern hemisphere (Antarctic and Namibia), the octachlorobornane B8-1413 (P-26) usually appeared at higher concentrations.Depending on the species the contribution of the other congeners varied significantly. B9-1025 (P-62) ranged from 2–20%, B8-1412 was found at 4–25% with highest contribution in birds, and B8-2229 (P-44) was found at 5–15%. The remaining three congeners B7-1453, B8-1414 (P- 40), and B8-1945 (P-41) were lower abundant except B8-1414 (P-40) which was found at high contribution in liver and kidney of birds.The sum of the eight CTTs ranged from 4μg/kg to 1.4 mg/kg, depending on the species and region. In most of the seal blubber samples, PCBs and DDT were more abundant (factor 2–20) but Antarctic Weddell seals showed higher CTT levels than PCBs and DDT.