Spectroscopic characterization of environmentally relevant C10-chloroterpenes from a photochemically modified toxaphene standard

Twenty-five pure environmentally relevant toxaphene components have been isolated from photochemically modified technical toxaphene by means of a combination of column chromatography on silica gel and preparative high resolution liquid chromatography. These compounds are 6 chlorinated camphenes (1–3, 5, 7, and 11) and 19 chlorinated bornanes (4, 6, 8–10, 12–16, 18–24, 26, and 27 according to Table 1). Two further chlorobornanes (17 and 25) have been isolated from a highly chlorinated mixture obtained by the excess chlorination of 2-exo,10-dichlorobornane. The structural elucidation of the isolated compounds has been carried out with spectroscopical methods.     

Analysis of Toxaphene

Abstract

Toxaphene, a widely and chlorinated hydrocarbon insecticide produced by chlorination of camphene, consists of a poorly defined mixture of at least 180–190 substances. Most of these conform the formulars C₁₀H₁₈-_nCl_n and C₁₀H₁₆-_nCl_n, where n is 6–10. Although the chromatographic behaviour of the toxaphene components is extremely similar, seven components have been isolated up to now, six of which are hepta- to decachlor derivatives of bornane. In the following work, isolation and identification of these compounds with the help of spectroscopical methods are described and their behaviour under biotic and abiotic conditions are studied. The experiments shown, that toxaphene is slowly to rapidly degraded in various environmental systems.     

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

Summary 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.     

Attempt to unravel the composition of toxaphene by comprehensive two-dimensional gas chromatography with selective detection

Comprehensive two-dimensional gas chromatography (GC x GC) coupled with micro electron-capture and time-of-flight mass spectrometric (TOF-MS) detection has been used to analyse technical toxaphene. An HP-1 x HT-8 column combination yielded highly structured chromatograms and revealed a complex mixture of over 1000 compounds what is significantly higher number than in any study before. The analysis of a mixture of 23 individual congeners and TOF-MS evaluation of technical toxaphene showed that the chromatogram is structured according to the number of chlorine substituents in a molecule. The nature of the compounds (bornane and camphene) does not appear to have any influence. The sum of the peak areas of all congeners in each group was calculated using laboratory-written software; based on these results, the composition of technical toxaphene as a function of the number of chlorine substituents was provisionally calculated and was found that hepta- and octachlorinated compounds represents 75% of the total toxaphene area.     

固相萃取–气相色谱–负化学源质谱法检测水果和蔬菜中的毒杀芬

采用改进的分散固相萃取(QuEchERs)法对样品进行前处理,建立水果和蔬菜中毒杀芬残留的气相色谱–负化学电离源质谱(GC–NCI–MS)检测方法。样品中的毒杀芬由正己烷提取,经吸附剂PSA+GCB净化,在GC–NCI–MS的选择离子扫描模式下进样分析。毒杀芬的色谱保留时间在12.5~18.0 min区间内,采用面积归一化法积分,外标法定量。毒杀芬质量浓度在0.050~2.000 mg/L范围内与色谱峰面积呈良好的线性关系,相关系数r=0.999 1。分别以蓝莓、黄桃、菠菜为基质,在0.025,0.050 mg/kg添加水平下,毒杀芬的回收率为107.2%~118.1%,测定结果的相对标准偏差为5.5%~8.8%(n=6),定量限为0.025 mg/kg。该方法检测快速,适用于水果和蔬菜中毒杀芬残留的日常检测。     

The analysis of chlorinated dibenzofurans in municipal fly ash: Supercritical fluid extraction vs Soxhlet

A multiresidue supercritical fluid extraction procedure for chlorinated dibenzofurans (PCDFs) has been optimized as an efficient method for the determination of these compounds in fly ash samples. The results were compared with those obtained by Soxhlet extraction. Extracts from the two procedures were analyzed by gas chromatography–mass spectrometry (HRGC–MS) Statistical analysis of the results confirmed that supercritical fluid extraction provides data with a relative standard deviation of less than 10% while Soxhlet extraction data show a much greater spread.     

Analysis of toxaphene (PCC) and chlordane in biological samples by NCI mass spectrometry

Several recent reports indicate that both toxaphene (polychlorocamphene, PCC) and chlordane are widespread pollutants in our environment. These insecticides, both complex mixtures of chlorinated hydrocarbons, are difficult to separate from each other. Thus the analyses of them in environmental samples are difficult and furthermore complicated by interferences from other chlorinated hydrocarbons such as PCB and DDT compounds. Mass fragmentography using the negative ions formed by chemical ionization proved to be useful to selectively detect the toxaphenes and the chlordanes without interferences from DDT. High concentrations of PCB still influence on the results and have to be removed in the clean-up procedure.     

Analysis of Toxaphene (PCC) and Chlordane in Biological Samples by NCI Mass Spectrometry

Abstract

Several recent reports indicate that both toxaphene (polychlorocamphene, PCC) and chlordane are widespread pollutants in our environment. These insecticides, both complex mixtures of chlorinated hydrocarbons, are difficult to separate from each other. Thus the analyses of them in environmental samples are difficult and furthermore complicated by interferences from other chlorinated hydrocarbons such as PCB and DDT compounds. Mass fragmentography using the negative ions formed by chemical ionization proved to be useful to selectively detect the toxaphenes and the chlordanes without interferences from DDT. High concentrations of PCB still influence on the results and have to be removed in the clean-up procedure.     

Illudalane sesquiterpenoids from the soft coral Alcyonium paessleri: the first natural nitrate esters

Fifteen illudalane sesquiterpenoids, alcyopterosins A-O (1-15) have been isolated from the subAntarctic soft coral Alcyonium paessleri which was collected at a depth of 200 m near the South Georgia Islands, and their structures were elucidated by spectroscopic techniques. Eight of these compounds (2, 3, 5-8, 10, and 13) are the first natural nitrate esters, while the other four (1, 4, 11, and 12) are chlorinated. These compounds are as well the first illudalane sesquiterpenoids to be isolated from the marine environment. Compounds 1, 3, 5, and 8 showed mild cytotoxicity toward human tumor cell lines.     

Chloropupukeanolides C-E: cytotoxic pupukeanane chlorides with a spiroketal skeleton from Pestalotiopsis fici

Chloropupukeanolides C–E ( 8 – 10 ), three highly functionalized secondary metabolites featuring a novel spiroketal skeleton derived from the chlorinated tricyclo‐[4.3.1.0^{3, 7}]‐decane (pupukeanane) and the 2,6‐dihydroxy‐4‐methylbenzoic acid moieties, were isolated from the scale‐up fermentation extract of the plant endophytic fungus Pestalotiopsis fici. The constitutions of compounds 8 – 10 were elucidated primarily by NMR experiments. Their relative configurations were deduced by analogy to metabolites 4 – 6 , which were previously isolated from the same fungus. The absolute configuration of 8 was assigned by X‐ray crystallography and those of 9 and 10 by quantum‐chemical CD calculations. Biogenetically, chloropupukeanolides C–E ( 8 – 10 ) are presumably derived from the same oxidation‐induced Diels–Alder reaction pathway as compounds 1 and 4 – 7 , via the putative biosynthetic precursors 2 and 3 . The opposite configurations of the complete “Southern parts” of 8 and 9 suggests that this Diels–Alder reaction is stereochemically not very selective. Compounds 8 – 10 showed significant cytotoxicity against a small panel of human tumor cell lines and weak activities against the pathogens of tropical diseases.     

Helium microwave-induced plasma mass spectrometric detection for reversed-phase high-performance liquid chromatography

Reversed-phase high-performance liquid chromatography (HPLC) is directly coupled to helium microwave-induced plasma mass spectrometry (He MIP-MS) for the element-selective detection of halogenated organic compounds. Absolute detection limits are approximately 50 pg Br for brominated compounds, 1 pg I for iodinated compounds, and 10 ng Cl for chlorinated compounds. The linear dynamic range for Br- and I-containing compounds is 3-4 orders of magnitude. However, the linear range for chlorinated species is severely limited by high background at m/z = 35. The relative standard deviation for repetitive injections is less than 10%. The helium microwave-induced plasma is operated at moderate powers (300-350 W) and with a total helium consumption of 6-8 L/min. The effect of organic solvents on the background mass spectrum is investigated.     

Group separation of organohalogenated compounds by means of comprehensive two-dimensional gas chromatography

Separations of 12 compound classes, polychlorinated biphenyls (PCBs), diphenyl ethers (PCDEs), naphthalenes (PCNs), dibenzothiophenes (PCDTs), dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), terphenyls (PCTs) and alkanes (PCAs), toxaphene, organohalogenated pesticides (OCPs), and polybrominated biphenyls (PBBs) and diphenyl ethers (PBDEs) by comprehensive two-dimensional gas chromatography were evaluated. Five column combinations, DB-1 x 007-210, DB-1 x HT-8, DB-1 x LC-50, DB-1 x 007-65HT and DB-1 x VF-23ms were used to study, primarily, group-type separations, but attention was devoted also to within-class separation, especially for those classes which were not addressed in much detail before, the PCNs, OCPs, PBBs and PCTs. The DB-1 x 007-210 column set did not offer any extra separation compared to one-dimensional GC. For the DB-1 x HT-8 column combination, the useful principle of congener separation on the basis of number of halogen substituents in a molecule was confirmed (PCBs, toxaphene) and extended (PCTs, PBDEs). No practically useful group-type separation was observed for this column combination. The DB-1 x LC-50 set provides group separation based on planarity: planar compounds such as PCDDs, PCDFs, PCDTs and PCNs are much more retained than, and therefore separated from, non-planar analytes. Within the classes of PCBs, PBBs and PCTs highly useful separation of planar from non-planar compounds was also observed. The DB-1 x 007-65HT column set effectively separates PCAs and PBDEs from all other compound classes, and provides a good separation of brominated and chlorinated analogue classes from each other. This column set was the most efficient one for within-class separation of OCPs and PCNs. Finally, DB-1 x VF-23ms yields excellent within-class separations, especially of non-aromatic compounds, viz. OCPs, toxaphene and PCAs. No group separation was observed here. The applicability of the approach was demonstrated for a sediment extract and a dust extract. In the sediment extract, PCDDs, PCDFs, PCAs and PCNs were identified and their efficient separation was achieved. In the dust sample, separation of PCAs and PBDEs was achieved and several new PBDE congeners were identified.     

Multiresidue method for the gas-chromatographic analysis of some polychlorinated and polybrominated pollutants in biological samples

Summary A multiresidue method for the analysis of a number of chlorinated and brominated organic compounds in biological samples has been developed. The method includes gas-chromatographic analysis of hexachlorinated and hexabrominated benzenes (HCB and HBB), polychlorinated and polybrominated biphenyls (PCB and PBB), polychlorinated phenols (PCP), guaiacols (PCG), paraffins (CP) and naphthalenes (PCN), polybrominated diphenyl ethers (PBDE) and the pesticides DDT, polychlorinated terpenes (PCC or toxaphene), chlordanes, hexachlorocyclohexanes (HCH), aldrin and dieldrin. The use of charcoal column in the clean-up procedure makes it also possible to analyze the planar PCB congeners (pPCB). Cod muscle samples were spiked with 10 and 50 times the detection levels of the compounds to be analyzed. The mean recoveries, relative to internal standards, for 40 compounds or compound groups were between 51 and 120%.     

Iridoid-glycoside isolation and purification from Premna fulva leaves

Premna fulva Craib, rich in iridoid glycosides, is widely used to treat periarthritis, osteoproliferation, pain, and other diseases. However, no studies have reported effective purification methods for obtaining iridoid glycosides as active materials. This paper describes an efficient strategy for separating iridoid glycosides from Premna fulva leaves using high-speed counter-current chromatography and preparative high-performance liquid chromatography. A two-phase solvent system, ethyl acetate/n-butanol/water (7.5:2.5:10, v/v), was selected for high-speed counter-current chromatography separation. The proposed method effectively separated and purified four iridoid glycosides and four lignans, including three new iridoid glycosides ( 4–6 ) and five known compounds ( 1–3, 7, 8 ), from Premna fulva leaves, indicating that high-speed counter-current chromatography combined with prep-HPLC can efficiently isolate catalpol derivatives from the genus Premna. Additionally, the in vitro anti-inflammatory activities of all isolated compounds were analyzed using lipopolysaccharide-stimulated RAW 264.7 cells, and the results indicated that six compounds ( 1 and 3–7 ) exhibited potential anti-inflammatory activities.     

Identification of chlorinated sulfur compounds in pulp mill effluents by GC-MS and GC-AED

Summary Three chlorinated dimethyl sulfones and five chlorinated thiophenes have been identified in the alkaline extraction liquor from a bleach plant by gas chromatography with atomic emission detection (GC-AED) and with mass spectrometry (GC-MS). The information on elemental content obtained by GC-AED enabled a rapid screening of the sulfur compounds and provided important structural information complementary to the mass spectral data. Quantitation was accomplished by GC-AED based on universal calibration.     

Advances in the environmental analysis of polychlorinated naphthalenes and toxaphene

Recent advances in the analysis of the chlorinated environmental pollutants polychlorinated naphthalenes (PCNs) and toxaphene are highlighted in this review. Method improvements have been realized for PCNs over the past decade in isomer-specific quantification, peak resolution, and the availability of mass-labeled standards. Toxaphene method advancements include the application of new capillary gas chromatographic (GC) stationary phases, mass spectrometry (MS), especially ion trap MS, and the availability of Standard Reference Materials that are value-assigned for total toxaphene and selected congener concentrations. An area of promise for the separation of complex mixtures such as PCNs and toxaphene is the development of multidimensional GC techniques. The need for continued advancements and efficiencies in the analysis of contaminants such as PCNs and toxaphene remains as monitoring requirements for these compound classes are established under international agreements.     

Characterization and sources of extractable organochlorine in white sucker downstream from bleached kraft pulp mills

Organochlorine, obtained by extraction with hexane–acetone mixture (3?:?1) of fillets of white sucker (Catostomus commersoni) sampled downstream of pulp mills and in a reference river, was characterized by gel-permeation chromatography, transesterification, neutron activation analysis, and gas chromatography with halogen-sensitive detection. It was found that over 78% of the extractable organochlorine (EOCl) is of relatively high molecular weight (>～350). Chlorinated fatty acids account for 43–80% of EOCl in the high-molecular-weight portion, while chlorobenzenes, chlorinated pesticides, and polychlorinated biphenyls account for 4–55% of EOCl in the low-molecular-weight portion. Though undetectable in reference fish, three particular chlorinated fatty acids, i.e. threo-5,6-dichlorotetradecanoic, threo-7,8-dichlorohexadecanoic and threo-9,10-dichlorooctadecanoic acids, are characteristic of EOCl from fish collected downstream of bleached kraft pulp mills using chlorine-based bleaching, representing about 30% of total EOCl, of which threo-5,6-dichlorotetradecanoic acid alone accounts for 60–70%. It is thus evident that, among chlorinated compounds discharged from bleached kraft pulp mills, threo-9,10-dichlorooctadecanoic acid, presumably generated in chlorine-based bleaching processes, is the most bio-accumulative in fish and can be biodegraded by fish into dichlorohexadecanoic and dichlorotetradecanoic acids, presumably via β-oxidative metabolism. These three compounds were also identified in suspended solids isolated from biologically treated final effluent discharged from a bleached pulp mill using 50% ClO₂ substitution, thus confirming the effluent-related source for downstream fish. The finding also suggests that β-oxidation of dichlorooctadecanoic acid may also be operative in micro-organisms.     

Preparation and structure of high-chlorinated bornane derivatives for the quantification of toxaphene residues in environmental samples

Summary The HRGC-determination of Taxophene® residues in the presence of other chlorinated hydrocarbons with similar retention times is often difficult. This problem can satisfactorily be overcome by using purely isolated high-chlorinated bornane derivatives (7–17) as standard. The method is highly selective for measuring toxaphene in complex environmental matrices, such as fish, and can also be used for evaluating the changes in the relative distribution that may have resulted from bioaccumulation and environmental transformation.Dedicated to Professor Dr. Wilhelm Fresenius on the occasion of his 80th birthday     

Gas chromatographic and mass spectrometric analysis of chlorinated catechols occurring in pulp bleach liquors

Summary Chlorination step (C-step), spent bleach liquor from a kraft pulp mill and the product from the chlorination of guaiacol in aqueous solution have been investigated for their content of chlorinated catechols. After separation the samples were derivatized with diazoethane and analysed by glass capillary gas chromatography with an electron capture detector. The external standard mixture of all ethylated chlorocatechols was used in the measurements. The structures of the compounds identified were confirmed by gas chromatography/mass spectrometry. Eight chlorinated catechols were identified from a sample prepared by chlorination of guaiacol with Cl₂ in aqueous solution. However, only four of these compounds could be detected from a bleach liquor sample.     

Polybrominated diphenyl ether congeners and toxaphene in selected marine standard reference materials

Polybrominated diphenyl ether (PBDE) congeners and components of the complex mixture toxaphene are stable in the environment and readily bioaccumulated into wildlife and human tissues. PBDEs are presently used in large quantities worldwide as flame retardants in textiles, furniture, computer equipment, and cables. Toxaphene is a complex mixture of chlorinated bornanes and bornenes that was the most heavily used pesticide in the United States until it was banned in 1982; however, some countries continue to use toxaphene. The National Institute of Standards and Technology has quantified PBDE congeners and toxaphene in several available Standard Reference Materials (SRMs) using methods of gas chromatography with electron impact mass spectrometry (GC-EI-MS) and GC negative chemical ionization (NCI) MS, respectively. SRM 1588a Organics in Cod Liver Oil and SRM 1945 Organics in Whale Blubber were examined for PBDE congeners 47, 99, 100, 153, and 154, total toxaphene, and toxaphene congeners 26, 50, and 62. SRM 1946 Lake Superior Fish Tissue was also examined for total toxaphene and toxaphene congeners. The sum of the PBDE congeners (mean, (1 SD) wet basis) for SRM 1945 was 150 ng g^–1 (7 ng g^–1). The concentration of PBDE 47 in SRM 1588a was 82.7 ng g^–1 (2.8 ng g^–1). Other PBDEs were detected in SRM 1588a but were not quantified due their low levels. The total toxaphene (wet mass basis) was 1,210 ng g^–1 (127 ng g^–1), 1,960 ng g^–1 (133 ng g^–1), and 3,980 ng g^–1 (248 ng g^–1) in SRMs 1945, 1946, and 1588a, respectively. The values for PBDEs and toxaphene determined in the SRMs, while not certified, indicate that the SRMs will be suitable control materials for PBDE and toxaphene analyses.