| 1. |
- Carlsson, Pernilla, et al.
(författare)
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Environmental pollutants in the Swedish marine ecosystem, with special emphasis on polybrominated diphenyl ethers (PBDE)
- 2011
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Ingår i: Chemosphere. - : Elsevier BV. - 0045-6535.
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Tidskriftsartikel (refereegranskat)abstract
- Levels of polybrominated diphenyl ethers (PBDEs), polybrominated biphenyls (PBBs), polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloroethane (DDT) and perfluorinated organic compounds (PFCs) were analysed in whole herring (Clupea harengus) and sprat (Sprattus sprattus), eggs from common eider (Somateria mollissima) and eggs and livers from herring gull (Larus argentatus) from the Swedish west coast. The contaminant values obtained were compared with published values from the Arctic marine ecosystem. Tetra- and penta-brominated PBDEs were detected at low levels in herring, sprat and common eider (ΣPBDE 0.3–2.0 ng g-1ww), while the levels were higher in the herring gull samples (ΣPBDE 1.3–29.9 ng g-1ww). Hexa-decaBDEs were also found in samples from herring gulls. Eggs from herring gulls from the sub-Arctic contained four times more PBDE than the Swedish herring gulls eggs. Fish samples from the Arctic had two times higher levels of PBDEs and DDTs than similar samples from Sweden. The higher levels of contaminants in fish and seabirds from the Arctic reflect differences in transport processes, feeding ecology (reflected by trophic levels) and metabolism. PBDEs contributed to <10% of the total contaminant load in all investigated samples. The relative contribution of DDTs was higher in fish and bird samples from the Arctic when compared to Swedish samples, e.g. 65% in glaucous gull livers compared to 10% in herring gull livers. This study shows that even though the Swedish west coast is more urban than the Arctic, higher pollutants levels are found in seabird species from the Arctic.
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| 2. |
- Dyrssen, David, et al.
(författare)
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Complexation of aluminum with DNA.
- 1987
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Ingår i: Journal of inorganic biochemistry. - 0162-0134 .- 1873-3344. ; 29:1, s. 67-75
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Tidskriftsartikel (refereegranskat)abstract
- The extent of complexation of aluminum(III) with DNA (Calf thymus, Sigma type I) was estimated by means of two experimental techniques: potentiometric titration with a fluoride selective indicator electrode and dialysis followed by aluminum determination by graphite furnace AAS. Both types of experiments indicate that aluminum(III) is bound to DNA. The data are treated by assuming an ion exchange reaction with the phosphate diester groups. Using Rt to denote the concentration of these groups the values of log [AlMn-3R]/(Rt-3[AlMn-3R])[Al3+] decrease from approx. 7.6 to 5.6 when the concentration of sodium chloride is increased from 1 to 100 mM. In the pH range 4.5-5.5 the ion exchange constant increases approximately 0.5 log units. Dialysis gives lower values for the complex formation constant than potentiometry.
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| 3. |
- Larsson, Tobias, 1974, et al.
(författare)
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Correction of inner-filter effect in fluorescence excitation-emission matrix spectrometry using Raman scatter.
- 2007
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Ingår i: Analytica chimica acta. - : Elsevier BV. - 1873-4324 .- 0003-2670. ; 583:2, s. 357-63
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Tidskriftsartikel (refereegranskat)abstract
- Fluorescence excitation-emission matrix (EEM) spectroscopy is a useful tool for interpretation of fluorescence information from natural water samples. One of the major problems with this technique is the inner-filter effect (IFE), i.e. absorption of light at both the excitation and emission wavelengths. The common solutions are to either dilute the sample or apply some form of mathematical correction, most often based on the measured absorbance of the sample. Since dilution is not always possible, e.g. in on-line or in situ EEM recordings, and corrections based on absorbance are hampered primarily by the use of a separate absorbance instrument, neither of these solutions is optimal. In this work, we propose a mathematical correction procedure based on the intensity of Raman scatter from water. This procedure was found to reduce the error after correction by up to 50% in comparison with two absorbance correction procedures. Furthermore, it does not require the use of a separate absorbance measurement, and it is applicable to on-line and in situ EEM recordings, where the IFE would otherwise cause problems.
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| 4. |
- Skoog, Annelie, et al.
(författare)
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Decoupling of total organic carbon concentrations and humic substance fluorescence in a an extended temperate estuary
- 2011
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Ingår i: Marine Chemistry. - 0304-4203. ; 124:1-4, s. 68-77
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Tidskriftsartikel (refereegranskat)abstract
- We present the first complete sections of humic substance fluorescence (HSfl)-values and total organic carbon (TOC) concentrations through the extended estuary of the Baltic Sea, Kattegat, and Skagerrak. Both HSfl-values and TOC concentrations correlated strongly with salinity, indicating terrestrial runoff as the main source for both components. However, their distributions do not result from a simple two end-member mixing and the two pools have different controls. In the Baltic Sea, surface water HSfl-values decreased from north to south, while TOC concentrations remained relatively constant, indicating an increasingly biologically-labile TOC pool from north to south. Both HSfl-values and TOC concentrations decreased strongly from the Baltic Sea to Kattegatt and Skagerrak. There were no major net sources or sinks for HSfl or TOC in Kattegat. However, the Jutland Current was an HSfl and TOC source for Skagerrak, probably derived from Danish rivers. Fraction of forested area in drainage basins of the Baltic Sea correlated positively with HSfl-values in freshwater end-members, but not with TOC concentrations. Land-runoff-volume relative to basin volume correlated positively with HSfl-values in surface waters, but not with TOC concentrations. In the Baltic Proper, deepwater oxygen concentrations correlated negatively with HSfl-values, indicating a significant source for HSfl (but not TOC) in suboxic and anoxic deepwaters. Photobleaching decreased HSfl-values in surface waters of the Baltic Proper, but had no effect on TOC concentrations. Despite terrestrial material being the main source for both TOC and HS, differences in control mechanisms result in a partial decoupling of their concentrations within the estuary.
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| 5. |
- Skoog, A, et al.
(författare)
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Spring distribution of dissolved organic matter in a system encompassing the Northeast Water Polynya: Implications for early-season sources and sinks
- 2005
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Ingår i: Marine Chemistry. - : Elsevier BV. - 0304-4203. ; 94:1-4, s. 175-188
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Tidskriftsartikel (refereegranskat)abstract
- This study addresses sources and diagenetic state of early-season dissolved organic matter (DOM) in the Northeast Water Polynya (NEWP) area northeast of Greenland from distributions of humic substance fluorescence (HSfl), dissolved organic carbon (DOC), and dissolved organic nitrogen (DON) in the water column inside and outside the NEWP area. The water masses of the polynya area had acquired their spring/summer temperature-salinity characteristics at the time of sampling, and also had individual, different DOM signatures. DOC concentrations were variable within and among water masses in the polynya area, indicating patchy local sources and sinks of DOC. PySW and polynya intermediate water (PyIW) had higher average DON concentrations and average lower C:N ratios than polynya bottom water (PyBW), indicating a larger fraction of fresh DOM in PySW and PyIW than in PyBW. Ice-covered, polynya area surface waters (PySW) had higher DOC concentrations (113 +/- 14 mu M, n=68) than surface water (SW) outside the polynya area (96 +/- 18 mu M, n=6). The DOM C:N ratios in a low-salinity, ice-melt subgroup of PySW samples indicate labile material, and these low-salinity surface waters appeared to have a local DOC and DON source. In contrast, HSfl was significantly lower inside than outside the NEWP area. Despite the lower HSfl values within the NEWP area, the PySW values were high when compared to open-ocean water. There were no local terrestrial sources for HSfl to the NEWP area and the East Greenland Current is therefore proposed as a likely source of allochtonous HSfl. When HSfl was used as a conservative tracer, up to similar to 70% of the water in PySW and PyIW was found to be derived from SW, which contains a high fraction of water from the East Greenland Current. Similarly, a mixing model based on HSfl indicated that similar to 80% of early-season DOC and 90-100% of early-season DON in PySW and PyIW were derived from SW, indicating a potentially high fraction of terrestrially-derived, relatively refractory DOM in the early-season NEWP area. (c) 2005 Elsevier B.V. All rights reserved.
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