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  • 1
    Electronic Resource
    Electronic Resource
    Air-Water Equilibrium of Hexachlorocyclohexanes and Chloromethoxybenzenes in the North and South Atlantic (1995)
    s.l. : American Chemical Society
    Environmental science & technology 29 (1995), S. 207-215 
    Details
    ISSN: 1520-5851
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology , Energy, Environment Protection, Nuclear Power Engineering
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/es00001a027
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  • 2
    Electronic Resource
    Electronic Resource
    Biomagnification of polychlorinated biphenyls (PCBs) in freshwater fish (1998)
    Springer
    Fresenius' journal of analytical chemistry 360 (1998), S. 816-819 
    Details
    ISSN: 1432-1130
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract A total of 19 PCB congeners were determined in muscle of 2 European roach (Rutilus rutilus) and in muscle and liver of 3 pike (Esox lucius) of a small rural lake in the southern Black Forest (Germany) to examine the biomagnification in freshwater fish. The lake is known for a relatively high PCB contamination of its sediments due to past local emissions. The presence of a structure dependent biomagnification in these freshwater fish of two different trophical levels is confirmed. The relative contents of PCB congeners with vicinal H-atoms in m,p- and to a lesser extent, o,m-positions become smaller from roach to pike indicating a stronger induction of PCB metabolizing isoenzymes in the predatory fish. This could also be shown by application of the metabolic slope concept.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002160050816
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  • 3
    Electronic Resource
    Electronic Resource
    EI- and NCI-mass spectrometry of arylalkyl nitrates and their occurrence in urban air (1999)
    Springer
    Fresenius' journal of analytical chemistry 364 (1999), S. 91-99 
    Details
    ISSN: 1432-1130
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The overall probability of the formation of arylalkyl nitrates is low in comparison to alkyl nitrates. However, measurable amounts of arylalkyl nitrates are found in traffic influenced air. It is reported here an analytical protocol based on high-volume sampling, adsorption liquid chromatography as a step in sample preparation, and high-resolution gas chromatography with electron ionization mass selective detection (HRGC/EI-MSD) as well as high-resolution gas chromatography with negative chemical ionization mass selective detection (HRGC/NCI (methane)-MSD) for the determination of arylalkyl nitrates as atmospheric constituents in urban air. The synthesis of arylalkyl nitrates as reference compounds is described. The arylalkyl nitrates can be selectively detected by the fragments M-46 (M-NO2) and M-48 (M-NO2-2H) in HRGC/NCI(methane)-MSD. In EI(70 EV)-MSD the dominating ions are at 46, 77, 91 and 105 u, which correspond to the NO2 + and the phenyl, benzyl, and ethylbenzene fragments, respectively. The molecular ions are missing in (NCI-methane)-MSD and are of medium intensity in EI-MSD. Phenylethyl and phenylpropyl nitrates elute in GC in the range of n-octyl to n-dodecyl nitrate. The following arylalkyl nitrates have been identified in urban air: Benzyl nitrate (PhC1) and the three xylyl nitrates (M-PhC1), phenylethyl-1-nitrate (1Ph1C2), phenylethyl-2-nitrate (1Ph2C2), phenyl-n-propyl-1-nitrate (1Ph1C3), and phenyl-n-propyl-2-nitrate (1Ph2C3). Benzyl nitrate is the dominating compound in this group and is found at levels of 10–300 ng/m3 in urban air.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002160051306
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  • 4
    Electronic Resource
    Electronic Resource
    Capillary gas chromatography of polychlorinated benzonitriles (PCBN) (1997)
    Springer
    Fresenius' journal of analytical chemistry 359 (1997), S. 561-564 
    Details
    ISSN: 1432-1130
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Polychlorinated benzonitriles (PCBN) are products of combustion chemistry and can be emitted from municipal waste incinerators. Their possible relevance to environmental chemistry has not previously been described, with the exception of the herbicide 2,6-dichlorobenzonitrile. The isomer-specific separation and detection of the 19 PCBN congeners is performed by HRGC-ECD and HRGC-MSD. Commercially unavailable congeners were synthesized from chlorinated anilines and benzaldehydes. Retention data on three different stationary phases are given. Structure-retention relationships are discussed. A structure-specific systematic numbering of the 19 PCBN congeners is suggested.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002160050632
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  • 5
    Electronic Resource
    Electronic Resource
    Isomer-specific determination of 79 polychlorinated diphenyl ethers (PCDE) in cod liver oils, chlorophenols and in a fly ash (1995)
    Springer
    Fresenius' Zeitschrift für analytische Chemie 351 (1995), S. 98-109 
    Details
    ISSN: 1618-2650
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The occurrence of polychlorinated diphenyl ethers (PCDEs) has been investigated in two different cod liver oils produced in 1985 and 1993, respectively, from North-Atlantic fish. These samples mirror the distribution of PCDEs among other persistent organochlorine compounds in the marine environment. To elucidate the input of PCDEs in the environment, five possible sources of PCDEs have been analyzed, namely two wood preserving formulations containing approximately 10% pentachlorophenol, two technical chlorophenol products, and one fly ash from a municipal waste incinerator. The determination has been based on 106 available PCDE congeners. During sample preparation a 2-(l-pyrenyl)ethyldimethylsilylated silica column has been used in the normal phase mode to separate the PCDEs from possible PCDF interferences. The PCDEs have been quantified by high resolution gas chromatography/mass spectrometry on a SE 54 capillary column using electron ionization and selected ion monitoring. The total amount of PCDEs in 2,3,4,6-tetrachlorophenol have been determined to be 213 mg/kg. The lowest concentrations of PCDEs have been found in the more recently produced cod liver oil (sum PCDEs: 49 μg/kg) and in the fly ash sample (sum PCDEs: 93 µg/kg), respectively. The isomer-specific analysis has been employed to characterize the relationship between possible sources and the PCDEs found in the environment. PCDEs, like PCBs, can be indicator molecules for the global pollution of the environment.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00324298
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  • 6
    Electronic Resource
    Electronic Resource
    Semivolatile organic compounds — polychlorinated dibenzo-p-dioxins (PCDD), dibenzofurans (PCDF), biphenyls (PCB), hexachlorobenzene (HCB), 4,4'-DDE and chlorinated paraffins (CP) — as markers in sewer films (1995)
    Springer
    Fresenius' Zeitschrift für analytische Chemie 352 (1995), S. 715-724 
    Details
    ISSN: 1618-2650
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract A municipal sewer system has been investigated for the sources of a set of semivolatile compounds, such as polychlorinated dibenzo-p-dioxins (PCDD), polychlorinated dibenzofurans (PCDF), polychlorinated biphenyls (PCB), hexachlorobenzene (HCB), 1,1-dichloro-2,2-bis(p-chlorophenyl)-ethene (4,4'-DDE), and chlorinated paraffins (CP), using sewer films as the sampling medium. A cleanup method for these semivolatile compounds in sewer films is described. The project has been undertaken for the differentiation and localization of specific inputs of xenobiotics from defined regions of the city. A unique pattern of PCDD/PCDF found in sewage sludge has led to the search for a specific source within the sewer system, which has finally been localized as a distinct plant. Other organochlorine compounds proved to be significant indicators for industrial and domestic sewers. PCB appeared as an industry correlated parameter, while 4,4'-DDE indicated domestic sewers. Chlorinated paraffins have been detected in the mg/kg range and are markers and indicators for metal-working industries. Finally, the release of CP by the sewage treatment plant, into the nearby river, has been investigated.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00323054
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  • 7
    Electronic Resource
    Electronic Resource
    Transformation experiments with two chiral endosulfan metabolites by soil microorganisms — CHIRAL HRGC on lipophilic cyclodextrin derivatives (1995)
    Springer
    Fresenius' Zeitschrift für analytische Chemie 352 (1995), S. 756-762 
    Details
    ISSN: 1618-2650
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Two chiral metabolites of the hexachlorinated cyclodien insecticide endosulfan, C9H6Cl6O3S, the endosulfan hydroxyether and the endosulfan lactone, were separated into their enantiomers using lipophilic β-cyclodextrin derivatives in chiral high-resolution gas chromatography (CHRGC). We separated the hydroxyether on heptakis-(2,3,6-tri-O-pentyl)-β-cyclodextrin (LIPODEX-C) and the endosulfan lactone on heptakis-(3-O-acetyl-2,6-di-O-pentyl)-β-cyclodextrin (LIPODEX-D). We also investigated the enantioselective formation and transformation of these two metabolites by soil organisms. To approximate real world conditions of microbiological transformation, incubation experiments with mixed cultures of soil microorganisms were carried out. Significant differences were observed in the transformation experiments under aerobic and anaerobic conditions. The endosulfan hydroxyether (ESH) is not formed enantioselectively from prochiral endosulfan diol (ESD) in the aerobic transformation pathway. The hydroxyether itself is enantioselectively converted to the endosulfan lactone (ESL) as a major pathway only under aerobic conditions. Corresponding enantiomers of endosulfan hydroxyether and endosulfan lactone with the same absolute configuration could be assigned. The lactone enantiomers are stereoselectively formed via the hydroxyether as a minor pathway under anaerobic conditions. While the first eluting lactone enantiomer was more abundant in the aerobic experiment, it was the second eluting under anaerobic conditions. Four major so far unidentified metabolites were detected in the anaerobic incubations of both the endosulfan hydroxyether and the endosulfan diol.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00323060
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  • 8
    Electronic Resource
    Electronic Resource
    Separation of Diastereomeric and Enantiomeric Alkyl Nitrates-Systematic Approach to Chiral Discrimination on Cyclodextrin LIPODEX-D (1996)
    Weinheim : Wiley-Blackwell
    Chemistry - A European Journal 2 (1996), S. 539-544 
    Details
    ISSN: 0947-6539
    Keywords: analytical methods ; alkyl nitrates ; chiral resolution ; cyclodextrins ; gas chromatography ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: High-resolution gas chromatographic separation of all diastereomeric monomethyl-substituted cyclohexyl nitrates is shown on a nonpolar methylpolysiloxane stationary phase, and the first application of this procedure to the environmental diastereomeric analysis of alkyl nitrates is presented. Two characteristic signals in the achiral analysis of atmospheric samples could be assigned to the smallest alkyl nitrate containing two asymmetric carbon atoms, 3-methyl-2-pentyl nitrate. Retention indices in the temperature-programmed separation based on the n-alkanes were determined. The homologous series of 1-alkyl nitrates were found to be useful as ECD-visible n-alkanes. Enantiomeric separation of alkyl nitrates was achieved on heptakis(3-O-acetyl,-2,6-di-O-pentyl)-β-cyclodextrin (LIPODEX-D). The influence of the nitrooxy group and the alkyl chain length on the chiral discrimination on LIPODEX-D is discussed for 25 chiral alkyl nitrates. The absolute configurations of some alkyl nitrates were assigned by asymmetric synthesis of enantiomerically pure references. The complexity of the alkyl nitrate mixtures present in air samples does not allow a direct chiral separation as the alkyl nitrates partly coelute on the LIPODEX-D column. Column coupling of LIPODEX-D with a polar achiral stationary phase like polyalkylenglycol (PAG) was successfully applied to solve this problem, and the chiral alkyl nitrates present in a typical air sample were separated. A systematic nomenclature for alkyl nitrates is introduced to handle the steadily growing number of branched and long-chain alkyl nitrates detected in environmental analysis.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/chem.19960020513
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