Thorough study of persistent organic pollutants and halogenated natural products in sperm whale blubber through preparative sample cleanup followed by fractionation with countercurrent chromatography.

Marine mammals are top predators of the marine food chain and thus known to bioaccumulate high concentrations of polyhalogenated compounds. Yet, details of the organohalogen pattern are largely unknown. For this reason, we isolated the polyhalogenated compounds from 750 g blubber of a sperm whale (Physeter catodon), which deceased at the German North Sea coast in January 2016. The sample matrix was decomposed by sulfuric acid treatment and the polyhalogenated compounds were then fractionated by countercurrent chromatography (CCC). Seventy-three CCC fractions were taken and analyzed by gas chromatography with electron capture negative ion mass spectrometry (GC/ECNI-MS). The bulk of the polyhalogenated compounds in the sample originated from classic persistent organic pollutants (POPs). Altogether 90 polychlorinated biphenyl (PCB) congeners were detected in the sample including all possible octa- to decachloro congeners except one. The sample also featured 105 toxaphene congeners including 30 chlorobornenes (contribution ∼14% of the total toxaphene content) which were only detected after the CCC fractionation. In addition, several chlordane and mirex related compounds were detected which were never or very scarcely described before in biota. Classic POPs (PCBs, DDT, toxaphene, chlordane, mirex) were predominant, while new emerging contaminants were scarcely detected. The sample featured several halogenated natural products (HNPs) some of which were less stable and destroyed during the sample cleanup involving treatment with sulfuric acid. Sample fractionation by means of CCC was crucial for the detection and assignment of many of the uncommon polyhalogenated compounds.

Toxaphene levels in retail food from the Pearl River Delta area of South China and an assessment of dietary intake.

Limited literature exists on toxaphene contamination in food worldwide, particularly in mainland China. In this study, three toxaphene congeners, Parlar 26 (B8-1413), Parlar 50 (B9-1679) and Parlar 62 (B9-1025), were analyzed in five different food categories from the Pearl River Delta Area in China using isotope dilution high-resolution gas chromatography/high-resolution mass spectrometry (HRGC/HRMS), and toxaphene levels in food were reported and toxaphene dietary intake by local residents estimated. The results showed that fish contained the highest toxaphene level with a median of 12.87 pg/g wet weight (ww), followed by poultry meat, egg products, livestock meat and vegetable, which had median levels of 5.8, 2.2, 1.89 and 0.67 pg/g ww, respectively. Parlar 50 and Parlar 26 were the predominant characteristic congeners in fish, and Parlar 26 was the predominant congener not only in poultry products and eggs, but also in livestock and vegetable. The estimated average daily intake found by local residents was 35.57 pg/kg body weight/day. Overall toxaphene levels and estimated dietary intake in the Pearl River Delta Area of South China are far lower than the European Maximum Residue Limits (EU MRLs), the German MRL for fish, and other international literature data. Therefore, the risk of adverse health effects from dietary intakes of toxaphene for the local residents is not considerable at the current time, but follow-ups are warranted to study dynamic changes of toxaphene in food in this area.

Fumio Matsumura--accomplishments at the University of California, Davis, and in the Sierra Nevada Mountains.

Fumio Matsumura joined the University of California, Davis, faculty in 1987 where he served as founding director of the Center for Environmental Health Sciences, associate director of the U.C. Toxic Substances Research and Teaching Program, and chair of the Department of Environmental Toxicology. He was an active affiliate with the NIEHS-funded Superfund Basic Research Program and the NIH Comprehensive Cancer Center. He was in many instances a primary driver or otherwise involved in most activities related to environmental toxicology at Davis, including the education of students in environmental biochemistry and ecotoxicology. A significant part of his broad research program was focused on the long range transport of chemicals such as toxaphene, PCBs and related contaminants used or released in California to the Sierra Nevada mountains, downwind of the urban and agricultural regions of the state. He hypothesized that these chemical residues adversely affected fish and wildlife, and particularly the declining populations of amphibians in Sierra Nevada streams and lakes. Fumio and his students and colleagues found residues of toxaphene and PCBs at higher elevations, an apparent result of atmospheric drift and deposition in the mountains. Fumio and his wife Teruko had personal interests in, and a love of the mountains, as avid skiers, hikers, and outdoor enthusiasts.

Toxaphene in the aquatic environment of Greenland.

The octa- and nonachlorinated bornanes (toxaphene) CHBs 26, 40, 41, 44, 50 and 62 were analysed in Arctic char (Salvelinus alpinus), shorthorn sculpin (Myoxocephalus scorpius), ringed seal (Pusa hispida) and black guillemot eggs (Cepphus grylle) from Greenland. Despite their high trophic level, ringed seals had the lowest concentrations of these species, with a Σ6Toxaphene median concentration of 13-20 ng/g lipid weight (lw), suggesting metabolisation. The congener composition also suggests transformation of nona- to octachlorinated congeners. Black guillemot eggs had the highest concentrations (Σ6Toxaphene median concentration of 971 ng/g lw). Although concentrations were higher in East than in West Greenland differences were smaller than for other persistent organic pollutants. In a circumpolar context, toxaphene had the highest concentrations in the Canadian Arctic. Time trend analyses showed significant decreases for black guillemot eggs and juvenile ringed seals, with annual rates of -5 to -7% for Σ6Toxaphene. The decreases were generally steepest for CHBs 40, 41 and 44.

Sorption and competition of two persistent organic pesticides onto marine sediments: Relevance to their distribution in aquatic system.

Sorption is a key process in the distribution of substances between environmental compartments in marine ecosystems. Two persistent organic pesticides, also known as toxaphene congeners, namely B8-1413 (P26) and B9-1679 (P50), are of special interest because they are not detected in sediments while relatively concentrated in marine mammals. Sorption-desorption, entrapment and competition behaviors of these pesticides onto marine sediments were studied to explain their environmental distribution. Data obtained under marine experimental conditions were fitted to sorption models to evaluate sorption coefficients and to assess the degree of B8-1413/B9-1679 entrapment of the two toxaphene congeners in sediments. Carbon normalized sorption coefficients (Koc) of both congeners were similar under in cold (2°C) marine (30 psu) conditions with high values ranging from 1.53×10(5) to 3.28×10(5) mL g(-1)indicative of a strong affinity to marine sediments However, the sorption-desorption investigations indicate that B8-1413/B9-1679 were on average 2.5 times less entrapped in sediments compared to B7-1450, a toxaphene congener known to accumulate predominantly in sediments. These results suggest that the low entrapment of B8-1413 and B9-1679 favor their availability and transfer to biological matrices.

Determining indicator toxaphene congeners in soil using comprehensive two-dimensional gas chromatography-tandem mass spectrometry.

Toxaphene, which is a broad spectrum chlorinated pesticide, is a complex mixture of several hundred congeners, mainly polychlorinated bornanes. Quantifying toxaphene in environmental samples is difficult because of its complexity, and because each congener has a different response factor. Toxaphene chromatograms acquired using one-dimensional gas chromatography (1DGC) show that this technique cannot be used to separate all of the toxaphene congeners. We developed and validated a sensitive and quantitative method for determining three indicator toxaphene congeners in soil using an isotope dilution/comprehensive two-dimensional gas chromatography-tandem mass spectrometry (GC × GC-MS). The samples were extracted using accelerated solvent extraction, and then the extracts were purified using silica gel columns. (13)C10-labeled Parlar 26 and 50 were used as internal standards and (13)C10-labeled Parlar 62 was used as an injection standard. The sample extraction and purification treatments and the GC × GC-MS parameters were optimized. Subsequently the samples were determined by GC × GC-MS. The limits of detection for Parlar 26, 50, and 62 were 0.6 pg/g, 0.4 pg/g, and 1.0 pg/g (S/N=3), respectively, and the calibration curves had good linear correlations between 50 and 1000 µg/L (r(2)>0.99). Comprehensive two-dimensional GC gave substantial improvements over one-dimensional GC in the toxaphene analysis. We analyzed soil samples containing trace quantities of toxaphene to demonstrate that the developed method could be used to analyze toxaphene in environmental samples.

[Analysis of toxaphene and its eight congeners in sediment and fish tissue by gas chromatography-negative ion mass spectrometry].

Toxaphene quantification incorporating gas chromatography/negative chemical ionization mass spectrometry (GC/NCI-MS) offers improved sensitivity and specificity. The U. S. Environmental Protection Agency (USEPA) recently released a GC/NCI-MS method (Method 8276) for the measurement of technical toxaphene and eight specific congeners (Hx-Sed, Hp-Sed, P26, P41, P40, P44, P50 and P62). However, there is still lack of a practical and complete analytical method including sample extraction, clean up, instrumental analysis, and data analysis. The goal of this work was to develop a ready-to-use method for the quantification of total toxaphene and the eight congeners. Sediment and salmon fish tissue were selected as sample matrices and extracted with methylene chloride using an accelerated solvent extraction system. The sample extracts were cleaned up with active copper powder or gel permeation chromatography, and finally silica/alumina combination column. Separation was performed on a DB-XLB column. GC/NCI-MS was operated under selected ion monitoring mode with an identical set of confirmation and quantitation ions for total toxaphene and the eight congeners. Oxygen reaction of polychlorinated biphenyls (PCB) was monitored by PCB204, an internal calibration standard, and the reaction level was kept below 1%. Average relative response factors were used in quantitation. Quantitation of total toxaphene employed the sum of all detectable (S/N > or = 3) 6-C1 to 10-Cl homolog peak areas, while the individual congeners were quantified followed the standard procedures for single analytes. Multi-point calibration solutions ranged from 0. 5 (5 for P62) to 500 microg/L for the individual congeners, and 50 to 500 microg/L for technical toxaphene, with the lowest calibration levels as lower limits of quantitation. Average congener recovery was (90.8 +/- 17.4)% (n =10) in spiked sediment with relative standard deviations of 5.4% - 12.8% (n =10), underscoring an excellently accurate and precise method. The method was applied to analyze sediment and fish tissue sample.

Scavenging amphipods: sentinels for penetration of mercury and persistent organic chemicals into food webs of the deep Arctic Ocean.

Archived specimens of the scavenging amphipod Eurythenes gryllus, collected from 2075 to 4250 m below the surface on five expeditions to the western and central Arctic Ocean between 1983 and 1998, were analyzed for total mercury (∑Hg), methyl mercury (MeHg), polychlorinated biphenyls (PCBs) and other industrial or byproduct organochlorines (chlorobenzenes, pentachloroanisole, octachlorostyrene), organochlorine pesticides (OCPs), and polybrominated diphenyl ethers (PBDEs). Median ∑Hg concentrations ranged from 70 to 366 ng g(-1) wet weight (ww). MeHg concentrations (3.55 to 23.5 ng g(-1) ww) accounted for 1.7 to 20.1% (median 3.7%) of ∑Hg. ∑Hg and MeHg were positively and significantly correlated with ww (∑Hg r(2) = 0.18, p = 0.0004, n = 63; MeHg r(2) = 0.42, p = 0.0004, n = 25), but not significantly with δ(13)C nor δ(15)N. Median concentrations of total persistent organic pollutants (POPs) ranged from 9750 to 156,000 ng g(-1) lipid weight, with order of abundance: ∑TOX (chlorobornanes quantified as technical toxaphene) > ∑PCBs > ∑DDTs > ∑chlordanes > ∑mirex compounds > ∑BDEs ∼ ∑chlorobenzenes ∼ octachlorostyrene > α-hexachlorocyclohexane ∼ hexachlorobenzene ∼ pentachloroanisole. Enantioselective accumulation was found for the chiral OCPs o,p'-DDT, cis- and trans-chlordane, nonachlor MC6 and oxychlordane. Lipid-normalized POPs concentrations were elevated in amphipods with lipid percentages ≤10%, suggesting that utilization of lipids resulted in concentration of POPs in the remaining lipid pool. Multidimensional Scaling (MDS) analysis using log-transformed physiological variables and lipid-normalized organochlorine concentrations distinguished amphipods from the central vs western arctic stations. This distinction was also seen for PCB homologues, whereas profiles of other compound classes were more related to specific stations rather than central-west differences.

The effect of co-occurring polychlorinated biphenyls on quantitation of toxaphene in fish tissue samples by gas chromatography negative ion mass spectrometry.

Determinative methods based on gas chromatography-negative chemical ionization mass spectrometry (GC-NCI/MS) provide improved sensitivity and specificity for toxaphene in environmental samples, but are subject to misidentification due to oxygen reaction in the presence of polychlorinated biphenyls (PCBs). The goal of this study was to quantify the impact of co-occurring PCBs in fish tissue samples when utilizing single quadrupole instruments to implement this method. Mixtures of PCB congeners and technical toxaphene, and extracts of fish tissue with varying concentrations of PCBs were analyzed for individual congener and total toxaphene concentrations by GC-NCI/MS. The contribution of co-injected PCB 204 ranged from 23% to 88% of the total peak area for the Cl-9 toxaphene homolog quantitation ion, a contribution that increased as the ratio of technical toxaphene to PCB 204 decreased. PCB interferences in fish tissue extracts, including a standard reference material, were subtracted using a three-step procedure featuring spectral analysis of isotopic patterns for target peaks. Total toxaphene concentrations without PCB subtraction in three fish tissue samples with low, intermediate and high co-occurring PCBs were overestimated by 33, 55 and 745%, respectively, underscoring the need for practical strategies to account for PCB interferences in GC-NCI/MS based protocols. In contrast, no appreciable interference or resulting positive bias in concentrations was observed for quantitation of eight common toxaphene residue congeners.

[Determination of seven toxaphene congeners in ginseng and milkvetch root by gas chromatography tandem mass spectrometry].

A novel method for the determination of representative toxaphene congeners in traditional Chinese herbal medicines was developed. Ginseng and Milkvetch Root were selected as the samples and seven toxaphene congeners were selected as the monitoring objects. The samples were extracted by accelerated solvent extraction with cyclohexane-acetone (9:1, v/v), then cleaned-up by Florisil solid phase extraction with hexane as the eluent and the residues were detected by gas chromatography-electron ionization tandem mass spectrometry (GC-EI-MS/MS) in multiple reaction monitoring (MRM) mode. The performance was demonstrated by the analysis of Ginseng and Milkvetch Root samples spiked with toxaphene congeners at three concentration levels of 0.005, 0.01 and 0.1 mg/kg. The recoveries ranged from 72.4% to 105% with the relative standard deviations (RSDs) of 0.96%-10.4%. The limits of detection (LODs) were 0.2-1.7 microg/kg. This method is sensitive and efficient in the aspect of extraction, and can be applied to monitor the residue of toxaphene congeners in Ginseng and Milkvetch Root.

Toxicological risks to humans of toxaphene residues in fish.

A revised risk assessment for toxaphene was developed, based on the assumption that fish consumers are only exposed to toxaphene residues that differ substantially from technical toxaphene due to environmental degradation and metabolism. In vitro studies confirmed that both technical toxaphene and degraded toxaphene inhibit gap junctional intercellular communication that correlates with the mechanistic potential to cause tumor promotion. In vivo rat studies established the NOAEL for degraded and technical toxaphene at the highest dose tested in the bioassay. Toxaphene residue intakes from European fishery products were estimated and compared to the provisional tolerable daily intakes (TDIs) from various regulatory agencies including Canada, the United States, and Germany. The estimated intake was also compared to a new calculated provisional MATT pTDI. The MATT pTDI is based on new toxicological information (in vivo rat studies) developed on a model for environmental toxaphene residues rather than technical toxaphene. A MATT pTDI (1.08 mg total toxaphene for a person of 60 kg) for tumor promotion potency was adopted for use in Europe and is referred to here as the MATT pTDI. These new data result in a better estimate of safety and a higher TDI than previously used. Based on realistic fish consumption data and recent baseline concentration data of toxaphene in European fishery products, the toxaphene intake for the consumers of Germany, Ireland, Norway, and the Netherlands was estimated. For an average adult fish consumer, the average daily intake of toxaphene was estimated to be 1.2, 0.4, 0.5, and 0.2 µg for the consumers of Norway, Germany, Ireland, and the Netherlands, respectively. The toxaphene intake of these average fish consumers was far below the MATT pTDI of 1.08 mg/60 kg bw. In conclusion, based on the most relevant toxicological studies and the most realistic estimates of fish consumption and recent concentrations of toxaphene in European fishery products, adverse health effects are unlikely for the average European consumer of fishery products. In no case is the MATT pTDI exceeded.

Historical trends in human dietary intakes of endosulfan and toxaphene in China, Korea and Japan.

Recently, the Stockholm Convention prohibited the use of toxaphene and has been reviewing endosulfan. The historical use of these pesticides may contaminate food and tend to accumulate in the food chain. In this study, to evaluate the spatial and temporal trends of food contamination, the endosulfan and toxaphene levels were measured in pooled 24-h food composite samples from Chinese (n=10), Korean (n=10) and Japanese (n=40) adults in the 1990s and 2007-2009. Endosulfan was detected in 32 of 40 samples from Japan, but its levels (sum of α- and ß-isomers) were low in both the 1990s and 2009 (range as geometric mean (geometric standard deviation) [GM (GSD)]: 0.96 (1.6)-1.42 (1.4) ng kg(-1)d(-1)). The dietary intakes of endosulfan in Seoul as GM (GSD) were 38.68 (1.3) ng kg bw(-1)d(-1) in 1994 and 92.17 (4.4) ng kg bw(-1)d(-1) in 2007, and significantly higher than those in Japan (p<0.05). The samples from Beijing showed a 50-fold increase in the endosulfan levels from 1993 (GM: 0.58 ng kg(-1)d(-1)) to 2009 (GM: 24.91 ng kg bw(-1)d(-1)) (p<0.05). Toxaphene was detected in 33 of 40 samples from Japan. The dietary intake of toxaphene in Japan (sum of Parlars #26, #50 and #62) was 0.32-1.21 ng kg bw(-1)d(-1) (range as geometric mean) and no temporal trend was observed. The dietary intake of toxaphene in Seoul increased significantly from 0.2 ng kg bw(-1)d(-1) (GM) in 1994 to 3.6 ng kg bw(-1)d(-1) (GM) in 2007 (p<0.05). Only one of 10 pooled samples from Beijing contained a detectable level of toxaphene (0.3 ng kg bw(-1)d(-1)). For the entire population, the risk of adverse health effects from dietary intakes of endosulfan and toxaphene is unlikely. However, the concentrations of endosulfan in several samples exceeded 10% of the acceptable daily intake limit value of 6 µg kg bw(-1)d(-1) set by the World Health Organization (WHO). It appears important to refine dietary intake estimates targeting food types and source identification to ensure safe food for consumers.

Modeling toxaphene behavior in the Great Lakes.

Chlorinated camphenes, toxaphene, are persistent organic pollutants of concern in the Great Lakes since elevated concentrations are found in various media throughout the system. While concentrations have decreased since their peak values in the 1970s and 80s, recent measurements have shown that the rate of this decline in Lake Superior has decreased significantly. This modeling study focused on toxaphene cycling in the Great Lakes and was performed primarily to determine if elevated water and fish concentrations in Lake Superior can be explained by physical differences among the lakes. Specifically, the coastal zone model for persistent organic pollutants (CoZMo-POP), a fugacity-based multimedia fate model, was used to calculate toxaphene concentrations in the atmosphere, water, soil, sediment, and biota. The performance of the model was evaluated by comparing calculated and reported concentrations in these compartments. In general, simulated and observed concentrations agree within one order of magnitude. Both model results and observed values indicate that toxaphene concentrations have declined in water and biota since the 1980s primarily as the result of decreased atmospheric deposition rates. Overall the model results suggest that the CoZMo-POP2 model does a reasonable job in simulating toxaphene variations in the Great Lakes basin. The results suggest that the recent findings of higher toxaphene concentrations in Lake Superior can be explained by differences in the physical properties of the lake (primarily large volume, large residence time and cold temperatures) compared to the lower lakes and increased recent inputs are not needed to explain the measured values.

Polybrominated diphenyl ethers, toxaphenes, and other halogenated organic pollutants in great blue heron eggs.

The great blue heron (Ardea herodias) has been used as a bioindicator of the state of the St. Lawrence River (Québec, Canada) since 1996. At 5-year intervals, selected breeding colonies along the River and its estuary are visited to estimate reproductive success and determine levels of contamination. Brominated flame retardants are found in many ecosystems and are increasing in concentration in the Great Lakes, which is the source of much of the water for the St. Lawrence River. In 2001 and 2002, in addition to polychlorinated biphenyls (PCBs) and chlorinated pesticides, the levels of polybrominated diphenyl ethers (PBDEs), polychlorinated bornanes (toxaphene) congeners and non-ortho-substituted PCBs were measured for the first time in pools of great blue heron eggs. The PBDE levels in great blue heron eggs (70-1,377 ng/g wet wt) were comparable to those measured in herring gull (Larus argentatus) eggs from the Great Lakes. Toxaphene was detected in great blue heron eggs at levels comparable to those of other major chlorinated pesticides. Major toxaphene congeners were octachlorobornane P44 and the nonachlorobornane P50. Environ.

Temporal trends of legacy POPs in Arctic biota, an update.

A statistically robust method was applied to 316 time-series of 'legacy' persistent organic pollutants (POPs) in Arctic biota from marine, freshwater and terrestrial ecosystems with the purpose of generating a 'meta-analysis' of temporal trend data collected over the past two to three decades for locations from Alaska in the west to northern Scandinavian in the east. Information from recently published temporal trend studies was tabulated and comparisons were also drawn with trends in arctic air. Most of the analysed time-series of legacy POP compounds showed decreasing trends, with only a few time-series showing significantly increasing trends. Compounds such as alpha-HCH, gamma-HCH and SigmaDDT had a relatively high proportion of time-series showing significantly decreasing trends; SigmaCHL had the lowest proportion. beta-HCH was an exception, where long-range transport through the ocean, and not the atmosphere, may explain several increasing trends that were detected in the Canadian Arctic. Moving east from the Canadian Arctic there was a trend towards a greater proportion of significantly decreasing trends. Several time-series for DDE and SigmaDDT showed significantly non-exponential trends, most often with a period of relative stability followed by a decrease. The median 'minimum detectable annual change within a 10-year period' for all of the time-series considered was 12% which did not meet the desirable level of statistical power capable of detecting a 5% annual change with a significance level of 5% within a 10-year period. The trends observed in the biota were consistent with decreasing trends of legacy POPs reported for Arctic air which appear to follow historic decreases in emissions. However, recent decreases in air are also starting to show signs of levelling off which may be an indication that atmospheric concentrations and, consequently those in the biota, are being less driven by primary sources and more by environmental processes and degradation.

Toxaphene analysis in Great Lakes fish: a comparison of GC-EI/MS/MS and GC-ECNI-MS, individual congener standard and technical mixture for quantification of toxaphene.

Toxaphene is considered to be a problematic organochlorine pollutant because of its bioaccumulation potential and persistence in aquatic environments. In this study, whole lake trout and walleye composites were used to evaluate two analytical techniques for total toxaphene and selected congener analysis. The efficacy of using gas chromatography electron ionization tandem mass spectrometry (GC-EI/MS/MS) and electron capture negative ionization mass spectrometry (GC-ECNI-MS) were compared. Although the sensitivity using GC-ECNI-MS was approximately five times greater than GC-EI/MS/MS, the latter provided more consistent inter-Parlar relative response factors (RRF). When using technical calibration mixtures, these results suggest a more accurate total toxaphene measurement was obtained using the GC-EI/MS/MS method. Total toxaphene concentrations in lake trout composites from both methods were highly correlated (R(2) = 0.985) with the MS/MS concentrations approximately half of those determined by ECNI, suggesting systematic high bias in toxaphene concentrations when measured using GC-ECNI.

Persistent organochlorine pollutants and toxaphene congener profiles in bottlenose dolphins (Tursiops truncatus) frequenting the Turtle/Brunswick River Estuary (TBRE) in coastal Georgia, USA.

Although the Turtle/Brunswick River Estuary (TBRE) in coastal Georgia (USA) is severely contaminated by persistent organochlorine pollutants (POPs), little information regarding POPs in higher-trophic-level biota in this system is available. In the present study, polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs; including DDTs, chlordanes, and mirex), and chlorinated monoterpenes (toxaphene) were measured using gas chromatography with electron-capture detection and gas chromatography with electron-capture negative ion mass spectrometry (GC-ECNI-MS) in blubber of free-ranging and stranded bottlenose dolphins (Tursiops truncatus). Mean total PCBs (78.6 +/- 32.4 microg/g lipid) and toxaphene (11.7 +/- 9.3 microg/g lipid) were significantly higher in dolphins sampled in the TBRE than in dolphins stranded near Savannah (GA, USA) 80 to 100 km to the north. Levels of OCPs were several-fold lower than levels of PCBs; moreover, PCBs comprised 81 and 67% of the total POP burden in TBRE and non-TBRE dolphins, respectively. Analyses with GC-ECNI-MS revealed that 2,2,5-endo,6-exo,8,8,9,10-octachlorobornane (P-42a), a major component in technical toxaphene and a major residue congener in local estuarine fish species, was the most abundant chlorobornane in both sets of blubber samples. Mean total POP concentrations (sum of PCBs, OCPs, and toxaphene) approached 100 microg/g lipid for the TBRE animals, well above published total PCB thresholds at which immunosuppresion and/or reproductive anomalies are thought to occur. These results indicate extended utilization of the highly contaminated TBRE as habitat for a group of coastal estuarine dolphins, and they further suggest that these animals may be at risk because of elevated POP concentrations.

Persistence of organochlorine chemical residues in fish from the Tombigbee River (Alabama, USA): Continuing risk to wildlife from a former DDT manufacturing facility.

Organochlorine pesticide and total polychlorinated biphenyl (PCB) concentrations were measured in largemouth bass from the Tombigbee River near a former DDT manufacturing facility at McIntosh, Alabama. Evaluation of mean p,p'- and o,p'-DDT isomer concentrations and o,p'- versus p,p'-isomer proportions in McIntosh bass indicated that DDT is moving off site from the facility and into the Tombigbee River. Concentrations of p,p'-DDT isomers in McIntosh bass remained unchanged from 1974 to 2004 and were four times greater than contemporary concentrations from a national program. Total DDT in McIntosh bass exceeded dietary effect concentrations developed for bald eagle and osprey. Hexachlorobenzene, PCBs, and toxaphene concentrations in bass from McIntosh also exceeded thresholds to protect fish and piscivorous wildlife. Whereas concentrations of DDT and most other organochlorine chemicals in fish have generally declined in the U.S. since their ban, concentrations of DDT in fish from McIntosh remain elevated and represent a threat to wildlife.

Development of a novel high volume band compression injector for the analysis of complex samples like toxaphene pesticide.

A new type of injector has been developed for gas chromatographic analysis. The injector has high volume and band compression (HVBC) capabilities useful for the analysis of complex samples. The injector consists essentially of a packed liner operated at room temperature while a narrow heated zone is used to axially scan the liner selectively desorbing the compounds of interest. The scanning speed, distance and temperature of the zone are precisely controlled. The liner is connected to an interface which can vent the solvent or any undesirable compounds, and transfer the analytes to an analytical column for separation and quantification. The injector is designed to be compatible with injection volumes from 1 to more than 250microL. At a low sample volume of 1microL, the injector has competitive performances compared to those of the "on-column" and "split/splitless" injectors for the fatty acid methyl esters and toxaphene compounds tested. For higher volumes, the system produces a linear response according to the injected volume. In this explorative study, the maximum volume injected seems to be limited by the saturation of the chromatographic system instead of being defined by the design of the injector. The HVBC injector can also be used to conduct "in situ" pretreatment of the sample before its transfer to the analytical column. For instance, a toxaphene sample was successively fractionated, using the HVBC injector, in six sub-fractions characterized by simpler chromatograms than the chromatogram of the original mixture. Finally, the ability of the HVBC injector to "freeze" the separation in time allowing the analyst to complete the analysis at a later time is also discussed.