A recently developed novel intense rare-gas excimer vacuum ultraviolet (VUV) light source, the electron beam-pumped excimer
lamp (EBEL), has been applied to the soft single-photon ionization (SPI) of organic molecules in a compact orthogonal acceleration
time-of-flight mass spectrometer (oaTOFMS). The SPI-oaTOFMS system was applied to the on-line monitoring of tobacco smoke. With this setup, it was possible to analyze the composition
of individual puffs of cigarette smoke. Furthermore, a gas chromatograph (GC) was coupled to the EBEL SPIoaTOFMS system. Soft photo-ionization represents an additional separation dimension. By combination of the gas chromatographic
and the soft-ionization mass spectroscopic separation dimensions, a truly multidimensional comprehensive analytical method
could be derived. 相似文献
Selected results from the degradation of reactive-dye hydrolysates after UV irradiation, ozonation and sodium peroxodisulphate (NaPS) treatment are presented. Reactive dyes with representative chromophores and anchor groups were chosen for the research project. Different stages of oxidative decolourisation were examined and determined by water parameters for biological degradation (BOD). The paper focuses on toxicity tests with Pseudomonas putida to consider whether the oxidative treatments result in products with a risk for the environment. Tests were performed with the AQUALYTIC® Sensomat System, which measures biological oxygen demand (BOD). It was determined that the chosen oxidative treatments had as a rule no bearing on respiration of P. putida. Experiments with hydrolysates after short-term UV irradiation resulted in a slightly increased but not long-lasting toxicity in comparison with treatments with ozone or NaPS. Toxic effects were found in tests with hydrolysates of metalliferous dyes. During oxidative treatment, metals were liberated from the chromophores. This did cause complete inhibition of respiration of P. putida. Dye Blue E, a member of a dye class with chlorotriazine anchor groups, was itself found to be toxic, caused by the reactivity of the anchor group. The hydrolysate is only of minor toxicity. 相似文献
The origin of polycyclic aromatic hydrocarbons (PAH) contamination in bulk atmospheric deposition at two sites of the Seine estuary, one urban and one industrial, has been investigated. The PAH profiles indicate that PAHs mainly have a pyrolytic origin, both in urban and industrial areas. PAH sources vary during the year with an increase of high molecular weight PAH proportions (especially for carcinogenic PAHs) in winter, that means an increase of combustion processes such as domestic heating. Ratios of indicator PAHs (FTH/FTH+PYR and IcdP/IcdP+BghiP) confirm the pyrolytic origin of PAHs. In summer, ratios show the presence of industrial sources. In addition to these two methods, a factor analysis/multiple linear regression model was applied and gave an approximation of PAH source apportionment. PAH were found to be associated predominantly with emissions from road traffic (gasoline and diesel), that accounts for 17-34%. Domestic heating is a very important PAH source in urban areas and accounts for up to 85% of PAHs in winter. Industrial emissions (refineries...) account for 25% in the industrial area in summer. Each is an identified source category for the region and these results are consistent with fly-ashes identified by scanning electron microscopy. This study demonstrates that a combination of source identification methods is a far more efficient than one method alone. 相似文献
A biomonitoring network with grass cultures was established near a chlor-alkali plant and the mercury concentration in the cultures were compared with the average atmospheric total gaseous mercury (TGM). Biomonitoring techniques based on different exposure periods were carried out. When comparing the mercury concentration in the grass cultures, both the average atmospheric TGM concentration during exposure and the exposure time determined to a large extent the accumulation rate of TGM. The maximum tolerable level of mercury in grass (approximately equal to 110 microg kg(-1) DM) corresponds with an average TGM concentration of 11 ng m(-3) for 28 days exposure. The background concentrations in grass were on an average 15 microg kg(-1) DM and the effect detection limit (EDL) was 30 microg kg(-1) DM. This value corresponds with an average TGM concentration of 3.2 and 4.2 ng m(-3) for 28 and 14 days exposure, respectively, which is in turn the biological detection limit (BDL) of ambient TGM. Exposures for 7 days were less appropriate for biomonitoring. 相似文献
The continuously growing global demands on a finite land resource will require better strategic policies and management of trade-offs to avoid conflicts between different land-use sectors. Visions of the future can support strategic planning by stimulating dialogue, building a consensus on shared priorities and providing long-term targets. We present a novel approach to elicit stakeholder visions of future desired land use, which was applied with a broad range of experts to develop cross-sectoral visions in Europe. The approach is based on (i) combination of software tools and facilitation techniques to stimulate engagement and creativity; (ii) methodical selection of stakeholders; (iii) use of land attributes to deconstruct the multifaceted sectoral visions into land-use changes that can be clustered into few cross-sectoral visions, and (iv) a rigorous iterative process. Three cross-sectoral visions of sustainable land use in Europe in 2040 emerged from applying the approach in participatory workshops involving experts in nature conservation, recreation, agriculture, forestry, settlements, energy, and water. The three visions—Best Land in Europe, Regional Connected and Local Multifunctional—shared a wish to achieve a land use that is sustainable through multifunctionality, resource use efficiency, controlled urban growth, rural renewal and widespread nature. However, they differ on the scale at which land services are provided—EU-wide, regional or local—reflecting the land-sparing versus land-sharing debate. We discuss the usefulness of the approach, as well as the challenges posed and solutions offered by the visions to support strategic land-use planning.