Metabolism of the mercapturic acid of 2,4′,5-trichlorobiphenyl in rats and mice
Synthesis of 4,4′-bis([3H]methylsulphonyl)-2,2′,5,5′-tetrachlorobiphenyl
Analysis of Toxaphene (PCC) and chlordane in biological samples by NCI mass spectrometry.
Emission of Carcinogenic Compounds with Automobile Exhaust
Different sampling methods for mutagenic polynuclear aromatic hydrocarbons (PAH) are described. These methods involve either direct sampling of raw exhausts which prior to filtering are cooled in a condenser, or filter sampling of exhausts diluted in a tunnel. The relevance of gas-phase PAHs of samples from diluted exhausts is discussed; methods used are either adsorbents (XAD-2) or cryogenic condensation. The emission of benzo(a)pyrene and certain other PAHs is reported from vehicles using different fuels (gasoline, diesel, LPG, alcohols) or different emission control systems. The emission of some volatiles, such as benzene, ethylene and alkylnitrites, is also presented from different types of fuels used.
Applicability of a cryogradient technique for the enrichment of PAH from automobile exhaust: Demonstration of methodology and evaluation experiments
A cryogradient system for the enrichment of polycyclic aromatic hydrocarbons from gasoline and diesel powered vehicles is described. The sampling involves particle trapping on a filter followed by gas phase enrichment in three separate condensers. The filter is extracted with dichloromethane (DCM). For the extraction of the condensers three different solvents have been used; cyclohexane, acetone and DCM. The latter has also been used together with three buffers, pH 3, pH 7 and pH 11. Analyses of polynuclear aromatic hydrocarbons were performed by means of glass capillary gas chromatography and mass spectrometry. These analyses of diluted gasoline exhausts show that of the phenanthrene/anthracene, fluoranthene/pyrene and their monoalkylated forms found, between 90 and 30% are present in the gas phase. For diesel emissions, corresponding values are between 50% and 5%, respectively. However, the distribution of PAH between gas phase and particles is dependent on dilution ratio and filter temperatures. The addition of NO2 (approximately 7 ppm) prior to filter sampling involves degradation of cyclopenteno(cd)pyrene (CPedP) and benzo(a)pyrene (BaP) on the particles from diluted gasoline exhausts. This also occurs with BaP on diesel particles sampled under equivalent conditions. Mutagenicity data from these experiments support the theory of formation of direct-acting mutagens, probably due to nitration. Parallel sampling of particles with Teflon-coated and glass fiber filters does not show that components which are reactive to NO2, e.g., CPcdP, are degraded to a lower extent when glass fiber filters are used.
Trace analysis of amines and isocyanates using glass capillary gas chromatography and selective detection. I. Determination of aromatic amines as perfluoro fatty acid amides using electroncapture detection
A method for the trace analysis of aromatic amines is presented. It involved conversion of the amines into the corresponding amides by reaction with a perfluoro fatty acid anhydride. The amides were separated by glass capillary gas chromatography and quantitation was achieved using on-column injection and electron-capture detection.
The method was applied to amines of interest from work environment health aspects. Detection limits were in the low picogram range. Columns suitable for this application and their preparation are discussed together with detector behaviour and the mass spectra of investigated perfluoro fatty acid amides.
Dry deposition of SO2 and NOx in winter.
Trace analysis of amines and isocyanates using glass capillary gas chromatography and selective detection. II. Determination of aromatic amines as perfluoro fatty acid amides using nitrogen-selective detection
Chlorinated Paraffins: Disposition of a polychloro-[1-14C]hexadecane in carp (Cyprinus Carpio) and bleak (Alburnus Alburnus).
EQUILIBRIUM CHARGE-DISTRIBUTION OF MULTIPLETS OF MONODISPERSE LATEX SPHERES
Determination of amino acids with 9-fluorenylmethyl chloroformate and reversed-phase high performance liquid chromatography
A new method for the determination of primary and secondary amino acids is presented. The reaction of 9-fluorenylmethyl chloroformate with amino acids proceeds under mild conditions in aqueous solution and is complete in 30 sec. The derivatives are highly fluorescent and stable, only the histidine derivative showing any breakdown. Twenty amino acid derivatives were separated in 20 min. A linearity range of 0.1-50,μM was obtained for most of the amino acids. The between-analyses relative standard deviation ranged from 2.4 to 6.4%. The detection limit is in the low fmol range.