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401.
Temporal variations in concentrations of perfluorinated carboxylic acids (PFCAs) and sulfonic acids (PFSAs), including perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA) structural isomers, were examined in livers of pilot whale (Globicephala melas), ringed seal (Phoca hisida), minke whale (Balaenoptera acutorostrata), harbor porpoise (Phocoena phocoena), hooded seal (Cystophora cristata), Atlantic white-sided dolphin (Lagenorhynchus acutus) and in muscle tissue of fin whales (Balaenoptera physalus). The sampling spanned over 20 years (1984-2009) and covered a large geographical area of the North Atlantic and West Greenland. Liver and muscle samples were homogenized, extracted with acetonitrile, cleaned up using hexane and solid phase extraction (SPE), and analyzed by liquid chromatography with negative electrospray tandem mass spectrometry (LC-MS/MS). In general, the levels of the long-chained PFCAs (C9-C12) increased whereas the levels of PFOS remained steady over the studied period. The PFOS isomer pattern in pilot whale liver was relatively constant over the sampling years. However, in ringed seals there seemed to be a decrease in linear PFOS (L-PFOS) with time, going from 91% in 1984 to 83% in 2006.  相似文献   
402.
Ramus K  Kopinke FD  Georgi A 《Chemosphere》2012,86(2):138-143
The effect of dissolved humic substances (DHS) on the rate of water-gas exchange of two volatile organic compounds was studied under various conditions of agitation intensity, solution pH and ionic strength. Mass-transfer coefficients were determined from the rate of depletion of model compounds from an apparatus containing a stirred aqueous solution with continuous purging of the headspace above the solution (dynamic system). Under these conditions, the overall transfer rate is controlled by the mass-transfer resistance on the water side of the water-gas interface. The experimental results show that the presence of DHS hinders the transport of the organic molecules from the water into the gas phase under all investigated conditions. Mass-transfer coefficients were significantly reduced even by low, environmentally relevant concentrations of DHS. The retardation effect increased with increasing DHS concentration. The magnitude of the retardation effect on water-gas exchange was compared for Suwannee River fulvic and humic acids, a commercially available leonardite humic acid and two synthetic surfactants. The observed results are in accordance with the concept of hydrodynamic effects. Surface pressure forces due to surface film formation change the hydrodynamic characteristics of water motion at the water-air interface and thus impede surface renewal.  相似文献   
403.
Two anticoccidial agents, salinomycin and robenidine, heavily used in the worldwide veterinary meat production, were investigated for their potential biotic degradation by cultured soil bacteria. The degradation-study was performed in lab-scale bio-reactors under aerobic and anaerobic conditions incubated for 200 h with a mixed culture of soil bacteria. Samples were analyzed by LC-MS/MS and potential transformation products were tentatively identified. Salinomycin was degraded under aerobic conditions and traces could be found after 200 h, however, seems more persistent under anaerobic conditions. Four transformation products of salinomycin were discovered. Robenidine was degraded under aerobic and anaerobic conditions, however, traces of robenidine were observed after 200 h. Five biotic transformation products of robenidine were discovered.  相似文献   
404.
Organochlorine pesticides are persistent lipophilic organic pollutants and tend to accumulate in growing plants. During growth, cork is in contact with the open air for long periods (9-12 years). Owing to the previous widespread use of organochlorine pesticides and their high persistence in the environment, there is a risk that residues of such pesticides may be present in cork.In this study, the concentrations of 14 organochlorine pesticides—all of which are indicators of environmental pollution—were analyzed in cork bark samples from three regions in Spain and one in Portugal. In addition, the concentrations of 2,4,6-trichlorophenol (TCP) and 2,4,6-trichloroanisole (TCA) were also analyzed.Our results show only very low concentrations of lindane, γ-HCH (<2.6 ng g−1) and its byproducts α-HCH (<3.5 ng g−1) and β-HCH (<0.6 ng g−1).Among the DDT and its metabolites, only two were found: p,p′-DDT was found in a cork sample from Extremadura (0.1 ng g−1) and p,p′-DDE was present at a maximum concentration of 2.9 ng g−1 in a cork sample from Castile-La Mancha. However, all concentrations were well below the legal limit established by Regulation (EC) No. 396/2005 (10 ng g−1 in foodstuffs). We can conclude, therefore, that the cork samples we studied complied with food safety standards.  相似文献   
405.

Purpose  

Prevalence of organic pollutants or their natural analogs in soil is often assumed to lead to adaptation in the bacterial community, which results in enhanced bioremediation if the soil is later contaminated. In this study, the effects of soil type and contamination history on diesel oil degradation and bacterial adaptation were studied.  相似文献   
406.

Introduction  

In this study, total petroleum hydrocarbon (TPH) contents and some aliphatic and aromatic hydrocarbon concentrations were analysed in coastal sediments of hot points collected from along the Southern Black Sea Shelf.  相似文献   
407.

Introduction  

We conducted a yearly polluted-reference sampling to assess the effects of petroleum pollution on life cycle characteristics of the meiobenthic nematode Odontophora villoti. Samples were taken every 15 days between 26 November 2004 and 25 November 2005 from two beaches of Bizerte bay (Tunisia), Rimel and Tunisian Refining Industries Company (TRIC). The latter site is located in front of the “Tunisian Refining Industries Company” runoff.  相似文献   
408.
Medium- and low-volatile organic chlorine (M/LVOCl) and PCDD/Fs in flue gas from various municipal waste incinerators (MWIs) were monitored. The sample for M/LVOCl was collected in an adsorption tube which was thermally desorbed and the amount of chlorine was measured by atomic emission spectrometry (AES) detection using radiofrequency helium plasma. The helium plasma excited chlorine having an optical emission line of 837.6 nm was monitored. The MVOCl and LVOCl were organic chlorine groups whose boiling points (bp) ranged from 70-120 degrees C and 170-270 degrees C, respectively. The compounds having bp 120-170 degrees C were distributed in two tubes. LVOCl correlated well with PCDD/Fs (ng/Nm3, r=0.81) in a wide range of 0.01-100 ng/Nm3 of PCDD/Fs, while the correlation of LVOCl vs. TEQ was less related (r=0.69). These results agreed with the fact that LVOCl monitored the amount of organic chlorine without molecular structure information, which is critical to toxicity. Since the bp of LVOCl was not identical with that of PCDD/Fs, the regression was effected by the conditions of the gas treatment devices. Because most data of 2001 were collected just after the installation of PCDD/Fs in MWIs, the regression of 2001 was slightly different from that of 2002-2003. Eliminating these initial unsteady data, the regression of LVOCl vs. PCDD/Fs became better, giving r= 0.86. Besides having PCDD/Fs as surrogates, M/LVOCl is valuable as a versatile element-selective organic chlorine monitor to improve thermal process control.  相似文献   
409.
Zhang F  Yediler A  Liang X 《Chemosphere》2007,67(4):712-717
In this study, an aqueous solution of purified, hydrolyzed C.I. Reactive Red 120 (RR 120, Color Index), was selected as a model to investigate the degradation pathways and to obtain additional information on the reaction intermediate formation. The dye was purified to avoid the influence of the impurities on the ozonation process and on the formation of oxidation by-products. To simulate the dye-bath effluents from dyeing processes with azo reactive dyes, a hydrolyzed form of the dye was chosen as a representative compound. High performance liquid chromatography/mass spectrometry and its tandem mass spectrometry was chosen to identify the decomposition pathways and reaction intermediate formation during the ozonation process. In addition total organic carbon and high performance ion chromatography analysis were employed to obtain further information on the reaction processes during ozonation. Purified, hydrolyzed RR 120 was decomposed under the direct nucleophilic attack by ozone resulting in oxidation and cleavage of azo group and aromatic ring, while the triazine group still remained in the solution even after prolonged oxidation time (120 min) due to its high resistance to ozonation. Phenol, 1,2-dihydroxysulfobezene, 1-hydroxysulfonbezene were detected as the degradation intermediates, which were further oxidized by O(3) and *OH to other open-ring products and then eventually led to simple oxalic and formic acid identified by HPIC.  相似文献   
410.
The polychlorinated biphenyls (PCBs) and DDT may bioaccumulate in the aquatic food web and have been of great concern due to their toxic effects on wildlife and human health. There is evidence showing that fish in the human diet contributes at a significant proportion to the total intake of PCBs and other organochlorine compounds, particularly fish with higher fat levels. This study investigated the concentration of PCBs and DDTs in muscle tissues of samples of the blue shark (Prionace glauca) and a swordfish (Xiphias gladius) from east Brazilian coast and estimate the human exposure to total DDTs through the consumption of both the species. Samples of the each species were caught between August and September 2001. The mean concentration for summation operator PCBs in P. glauca was 3.15 ng/g w.w. and the summation operator DDTs was 0.93 ng/g w.w. The mean concentration of summation operator PCBs in X. gladius was 6.50 ng/g and the mean of summation operator DDTs was 2.47 ng/g. The estimated daily intake of summation operator DDT through X. gladius or P. glauca consumption can be considered safe since it contributes to less than 0.1% of the limit of acceptable daily intake (ADI) of summation operator DDT proposed by WHO.  相似文献   
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