Photolytic clean-up of biological samples for gas chromatographic analysis of chlorinated paraffins

A method based on gas chromatography electron capture detection (GC-ECD) for the analysis of chlorinated paraffins (CPs) in biological samples has been investigated. The method includes photolytic destruction of halogenated aromatic compounds, such as PCBs, to eliminate some of the interferences in the analysis of CPs in environmental samples. Gel permeation chromatography was used to isolate CPs from the interfering components of Toxaphene and chlordane after the photolysis. GC-ECD gave a detection limit of 20 ng CPs/g fresh muscle tissue. The recovery of CPs from a spiked moose liver sample was estimated to 94%.     

Polychlorinated biphenyl (PCB) congeners and chlorinated pesticides in a cod liver oil reference material

A cod liver oil reference material, Standard Reference Material (SRM) 1588, which was issued by the National Institute of Standards and Technology (NIST) in 1989, has certified concentrations for five polychlorinated biphenyl (PCB) congeners and ten chlorinated pesticides. Recently, this SRM has been extensively characterized by additional analyses at NIST and by analyses at the Canadian Wildlife Service (CWS) where the SRM was used as a control sample during routine analyses of wildlife tissue specimens. In this paper the results from NIST and CWS are compared and the concentrations for over 40 PCB congeners and 20 chlorinated hydrocarbons are reported.     

Effect of some xenobiotics on kynurenine hydrolase and kynurenine aminotransferase of mouse liver

The effects of some xenobiotics on the activity of the B6-dependent kynurenine hydrolase (KH) and kynurenine aminotransferase (KATE) in mouse liver, were investigated. Polychlorinated biphenyl (Aroclor 1254) (400mg/kg/day x4) markedly decreased the activity of both enzymes. Benzo(a)pyrene (BP) and 3-methylcholanthrene (3-MC) (40mg/Kg/day x1) as well as phenobarbital (PB) (75mg/kg/day x3) did not alter the activity of KH, while that of KATE was mildy reduced. The response of the two enzymes to treatment with chlorpromazine (CPZ) (5mg/Kg/day x5) were opposite with marked elevation of KH and inhibition of KATE activities. Treatment with B-naphthoflavone (B-NF) (80mg/Kg/day x2), Pyrazole (200mg/Kg/day x1) or indole (400mg/kg/day x1) produce no change in the activity of either enzyme. It, seems therefore, that Aroclor (1254) and chlorpromazine may cause disordered kynurenine metabolism through alterations in the activities of its metabolizing enzymes. This, in turn, might affect nicotinamide adenine dinucleotide biosynthesis and/or the accumulation of some tryptophan metabolites suspected of being carcinogenic or co-carcinogenic.     

Effect of some xenobiotics on kynurenine hydrolase and kynurenine aminotransferase of mouse liver

Abstract

The effects of some xenobiotics on the activity of the B₆‐dependent kynurenine hydrolase (KH) and kynurenine aminotransferase (KATE) in mouse liver, were investigated. Polychlorinated biphenyl (Aroclor 1254) (400mg/kg/day ×4) markedly decreased the activity of both enzymes. Benzo(a)pyrene (BP) and 3‐methylcholanthrene (3‐MC) (40mg/Kg/day ×1) as well as phénobarbital (PB) (75mg/kg/day ×3) did not alter the activity of KH, while that of KATE was mildy reduced. The response of the two enzymes to treatment with chlorpromazine (CPZ) (5mg/Kg/day ×5) were opposite with marked elevation of KH and inhibition of KATE activities. Treatment with B‐naphthoflavone (B‐NF) (80mg/Kg/day ×2), Pyrazole (200mg/Kg/day ×1) or indole (400mg/kg/day ×1) produce no change in the activity of either enzyme. It, seems therefore, that Aroclor(1254) and chlorpromazine may cause disordered kynurenine metabolism through alterations in the activities of its metabolizing enzymes. This, in turn, might affect nicotinamide adenine dinucleotide biosynthesis and/or the accumulation of some tryptophan metabolites suspected of being carcinogenic or co‐carcinogenic.     

Chromatographic enantiomer separation of chiral xenobiotics and their metabolites--a versatile tool for process studies in marine and terrestrial ecosystems

A review discussing methodical aspects of enantioselective chromatographic separation of chiral environmental xenobiotics as well as examples for process studies reported in literature. The process studies include microbial transformation of chiral pollutants in aquatic ecosystems, their enzymatic transformation in biota, their photochemical degradation, air/sea exchange processes and atmospheric long range transport, and enantioselective toxic effects.     

Identification and quantification of chlorinated bisphenol A in wastewater from wastepaper recycling plants

Chlorinated derivatives of bisphenol A were detected in the final effluents of eight paper manufacturing plants in Shizuoka, Japan, where thermal paper and/or other printed paper is used as the raw material. Their amounts were determined by gas chromatography/mass spectrometry (GC/MS) after treatment with N, O-bis(trimethylsilyl)trifluoroacetamide, and ranged from traces to 2.0 microg/l. They are likely produced by chlorination of bisphenol A, which was released into the effluents from the pulping process of wastepaper, during or after bleaching with chlorine.     

Retention time profiling of all 136 tetra- through octa- chlorinated dibenzo-p-dioxins and dibenzofurans on a variety of Si-Arylene gas chromatographic stationary phases

The applicability of three different Silphenylene Silicone co-polymer (Si-Arylene) GC stationary phases (J&W Scientific DB-5ms, Varian VF-5ms, and VF-Xms) has been evaluated for the separation of all 136 tetra- through the octa- chlorinated dibenzo-p-dioxins (PCDD) and chlorinated dibenzofurans (PCDF) from closely eluting isomers using gas chromatography/high resolution mass spectrometry (GC/HRMS). Their relative performance data are compared to the “conventional” 5% diphenyl 95% dimethylpolysiloxane GC column (Supelco Equity-5) and to each other based on absolute retention times, visualized mass chromatograms, and the separation of 2,3,7,8-substituted isomers. VF-Xms GC column was able to demonstrate a better performance towards separation of 2,3,7,8-substituted PCDD/PCDF compared to other Si-Arylene GC columns tested, where only 2,3,4,7,8-PnCDF can not be resolved from 1,2,3,6,9-PnCDF and 2,3,4,6,7,8-/1,2,3,6,8,9-HxCDF and 1,2,3,7,8,9-/1,2,3,4,8,9-HxCDF can be at least partially resolved. These data suggest that the development of a single GC column for the separation of all 17 2,3,7,8-substituted dioxins and furans is feasible, which therefore could be used as a standard tool for the PCDD/PCDF methods globally including USEPA methods 1613b, 8290A, 8280B, European Standard Method EN 1948, Canadian methods DFPCB-E3418, EPS 1/RM/19, Japanese methods JIS K0311 and JIS K0312. Having one specific GC column to separate all 2,3,7,8-substituted PCDD/PCDF will significantly improve the data quality, comparability by the various methods and assessment techniques while simultaneously leading to a more cost and time efficient operation.     

Determination of bromate and chlorinated haloacetic acids in bottled drinking water with chromatographic methods

Disinfection by-products of interest such as bromate, chlorate and chlorinated haloacetic acids in 10 representative brands of bottled drinking water were investigated with ion chromatography. With the developed method, the detection limits of the disinfection by-products were in sub-microgl(-1) level. It was observed that bromate, chlorate and dichloroacetic acid could be detected in some water samples. In the bottled natural water, the concentrations for the three compounds were 0.1, 0.9 and 0.6 microgl(-1), respectively. The total concentration of disinfection by-products in the natural water sample was the highest among all the bottled drinking waters. The concentrations for the sum of disinfection by-products in the four types of bottled drinking water investigated were natural water > mineral water > spring water > purified water. The generation of disinfection by-products was much influenced by the original components and process procedure of the source water. The concentrations of bromate and chlorate in the bottled water samples hardly degraded with the increasing storage time. For dichloroacetic acid, with the prolonging of storage time, the concentration was much decreased.     

Studies on lethal concentrations and toxicity stress of some xenobiotics on aquatic organisms

Three widely used xenobiotics pentachlorophenol (PCP), 2,4-dichlorophenoxyacetic acid (2,4-D) and 2-chloro-2,6-diethyl-N-(butoxymethyl) acetanilide (Butachlor) are evaluated for acute toxicity and stress behavior on freshwater fish (Heteropneustes fossilis, Clarias batrachus, Channa punctatus) and mosquito larvae (Culex pipiens fatigans). The experiment was carried out by medium treatment using intermittent flow-through system. Median lethal concentrations (LC50) were calculated by probit analysis. The LC50 values and 95% confidence intervals showed variable range for tested chemicals. Mosquito larvae generally appeared resistant than fish, while H. fossilis was found to be most sensitive. Stress signs in the form of behavioral changes are also observed. Both types of organisms are recommended as good bioindicator for the risk assessment of aquatic environment due to chemicals tested.     

Polychlorinated organic compounds in the Arctic cod liver: trends and profiles

Polychlorinated organic compounds (POCs) have been measured in Arctic cod liver from Vestertana Fjord for a period of 1987-1998. Significant decrease was observed for DDD (p = 0.043), alpha-HCH (p = 0.001), and gamma-HCH (lindane; p = 0.001). Contents of DDE, 2,3,7,8-tetrachlorodibenzofuran, PCBs, chlordanes, chloronaphthalenes, hexachlorobenzene and polychlorodiphenyl ethers had no significant trend. Contents of three hexa- and two heptachlorodibenzofurans and octachlorodibenzofuran increased slightly from 1987 to 1994, but then at very high rate from 1994 to 1998. Trends of HCHs, profiles of PCBs and levels of chlordanes are in accordance with atmospheric long range transport. The hexa-, hepta- and octachlorodibenzofurans observed are major impurities in chlorophenol formulation Ky-5, which has been used as wood preservative and as fungicide/slimicide in industrial processes. Their profile in Vestertana cod was similar to that observed in Ky-5 contaminated fish.     

油气处理场站温室气体甲烷排放特征与量化

油气生产过程是甲烷重点排放源,对气候变化产生显著影响。采用便携式火焰离子检测器 (FID) 和Hi-Flow大流量仪等设备,对我国某油田3座油气处理场站甲烷泄漏排放特征进行了研究,明确了组件泄漏率,量化了重点源项甲烷排放速率,构建了设备设施甲烷排放因子,开展了甲烷排放量核算并提出了管控建议。结果表明,该油田油气处理场站设备组件与管线的甲烷泄漏率为0.7%~1.2%,压力表、阀门和储罐等在泄漏源项中占比较高。不同类型泄漏组件甲烷排放速率具有显著差异,处理场站的甲烷排放速率为111.66~274.63 L·min⁻¹。单个储罐和场站的甲烷排放因子分别为989.9 L·h⁻¹和0.19 L·m⁻³。3座场站年度甲烷排放量为303 783.40 m³,储罐是首要排放源,对总排放量贡献占比为94.1%。组件泄漏导致的甲烷排放主要源于高强度排放源,15%的泄漏点贡献了排放量的88.4%。该研究结果可为油田油气处理场站泄漏防控和温室气体排放控制提供参考。     

GC-profiles of chlorinated terpenes (Toxaphenes) in some Finnish environmental samples

The profiles of chlorinated terpenes in Finnish environmental samples were compared by GLC-SIM technique with those of toxaphene and Eastern European “dark”. The profiles in the seal blubber in the Northern and in the Eastern Baltic Sea proved to be similar. Chlorinated terpenes were found to be present in Finnish human milk.The spent bleach liquor of pine kraft pulp mill contained components having similar retention times and responses to those from toxaphene components.     

Trends in the levels of some chlorinated hydrocarbon residues in adipose tissue of Canadians

Trends in the levels of hexachlorobenzene, hexachlorocyclohexanes, oxychlordane, t-nonachlor, heptachlor epoxide, dieldrin, DDTs and polychlorinated biphenyls in adipose tissue of the Canadian population were followed from 1969 to 1985. Residues of lindane, dieldrin and p,p'-DDT continuously and significantly (P<0.025) decreased during that time, coinciding with restrictions on their use. Other residues also decreased significantly between 1969 and 1985, although not always continuously, while t-nonachlor levels did not change significantly since 1972. In general no consistent and/or significant differences were observed between the sexes, but in some instances differences were found for a particular residue in a given year. Three arbitrarily chosen age groups (0-25; 26-50 and > or =51 years) showed a downward trend in residue levels with time. The results of the surveys also indicate an increase in adipose tissue burden of chlorinated hydrocarbons with age, but this increase became apparently less significant with increasing age.     

Synthesis of polychlorinated dibenzofuran isomers and their gas chromatographic profiles

Fifty-one polychlorinated dibenzofuran (PCDF) isomers were synthesized by the structure specific methods starting from corresponding chlorophenol and chloronitrobenzene or chlorophenol and chlorodiphenyl iodonium salt. Structures of the synthesized PCDF isomers were confirmed by mass spectrometry and proton magnetic resonance spectroscopy. Gas chromatographic retention times and response factors of the PCDF isomers were determined on the fused silica capillary columns of SP-2330 and OV-101.     

Exposure to specific polychlorinated biphenyls and some chlorinated pesticides via breast milk in Poland

The aim of our study was to obtain the data on the exposure of breast-fed infants to polychlorinated biphenyls (PCBs) and selected organochlorine pesticides (OCPs) in the Wielkopolska province (Poland). The levels of indicator PCBs, and selected OCPs, including two DDT metabolites (HCB, p,p'-DDT, p,p'-DDD, p,p'-DDE and alpha,beta,gamma-HCH) were determined in 27 human milk samples, collected in 2000-2001, according to WHO protocol. Estimated daily intakes (EDIs) of all analytes were calculated. Our results were compared with those obtained by an analysis of human milk samples from other European and non-European countries, collected in the same period time. We have stated that median exposure of Wielkopolska first breast-fed infants to OCPs is comparable (EDI(HCB) = 0.086 microg/kgbw/day; EDI(beta-HCH)=0.063 microg/kgbw/day) or higher (EDI(p,p'-DDE) = 3.495 microg/kgbw/day) than in other European countries, while exposure to PCBs (EDI(Sigma7PCB) = 0.364 microg/kgbw/day) is situated at the low end of the intake of these xenobiotics by breast-fed infants from different regions of Europe.     

Temporal changes in some chlorinated hydrocarbon residue levels of Canadian breast milk and infant exposure

Between 1967 and 1986, five national surveys were carried out to determine organochlorine residues in Canadian breast milk. In these surveys the number of samples, their geographic sampling distribution and fat content changed over the years. In addition, the number of samples obtained from younger mothers decreased, while those from older mothers (31-40 years) increased. Total DDTs showed the most consistent decline of all declining residues, while PCBs only decreased after 1982. Levels of oxychlordane and trans-nonachlor remained constant. Ratios of p,p'-DDE/p,p'-DDT gradually increased from 3.1 to 10.0 over the same period of time. With few exceptions, regional trends in residue levels followed those observed for the whole country. Although the number of reported chemicals increased since 1967, this was not necessarily reflected in the total accumulated residues in breast milk. By 1986, the daily intakes of all compounds at 8 weeks of nursing were well below the established acceptable daily intakes.     

An equilibrium analysis of some chlorinated hydrocarbons in stoichiometric to fuel-rich post-flame combustion environments

The equilibrium composition of product gases from the combustion of chlorinated hydrocarbons (CHC) has been studied for varying ratios of C, H, Cl, and O under stoichiometric to fuel-rich conditions. An interactive, PC-compatible FORTRAN program, STANJAN, was utilized in conjunction with thermochemical data sources to calculate equilibrium compositions of gas mixtures as a function of temperature. The predicted results, when judiciously interpreted, assist in the understanding of the potential for formation of residual organic substance emissions (ROSEs) in post-flame environments of an incinerator. Arguments are presented for the potential formation of chlorinated species, which are stable at ambient temperature, if locally fuel-rich mixtures penetrate into the lower temperature zones of an incinerator. ROSEs that have been observed in field tests of incinerators burning chlorinated compounds are predicted to form under the fuel-rich condition. Furthermore, when the equivalence ratio is greater than unity by even a slight amount, the degree of chlorination of product gases increases markedly when the Cl/H ratio also exceeds unity. In that case, time, temperature, turbulence and an overall fuel-lean stoichiometry may not be sufficient to guarantee elimination of measurable levels of chlorinated products. Possible implications of the equilibrium calculations are discussed. Further systematic studies with additional CHCs, nitrogen-, sulfur-, and heavy metal-bearing compounds are recommended as well as continued efforts to carry out kinetic studies.