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Deposition of semivolatile organic compounds to spruce needles. 1. Calculation of dry and wet fluxes
1994
Umlauf, G. (Bayreuth Univ. (Germany). Lehrstuhl fuer Oekologische Chemie und Geochemie) | McLachlan, M.
The deposition of atmospheric tetrachlorobenzene, pentachlorobenzene, hexachlorobenzene, alpha-HCH, gamma-HCH, DDT, DDE and the PCB congeners 52, 101, 138, 153 and 180 to spruce needles (Picea abies) was estimated for a period of 9 months. Accumulation in spruce as a result of dry gaseous deposition, particle bound deposition and wet deposition was calculated on the basis of the corresponding deposition rates and the compounds' concentrations in the different atmospheric compartments. The comparison of the calculated values with the concentrations of the compounds measured in 9-month-old spruce needles showed that for many compounds each deposition pathway could explain a large part of the concentrations found in the needles.
اظهر المزيد [+] اقل [-]Immunoassay monitoring of polychlorinated biphenyls (PCBs) in the Great Lakes
1994
Richter, C.A. (Michigan State Univ., East Lansing (USA). Dept. of Fisheries and Wildlife. Pesticide Research Center. Inst. for Environmental Toxicology) | Drake, J.B. | Giesy, J.P. | Harrison, R.O.
Although polychlorinated biphenyls (PCBs) are no longer manufactured, they are still entering the environment. In some compartments of the environment, PCB concentrations are a serious concern. This is especially true in compartments which accumulate PCBs, and in food items consumed by humans and wildlife. Also, there are situations in which management decisions require rapid, sensitive, accurate measurements, which can be made in real time under field conditions. Methods to use an enzyme-linked immunosorbent assay (ELISA) for PCBs were developed and applied to sediments and fish muscle homogenates collected from the Great Lakes. The extraction methods developed can be applied in the field with non-hazardous solvents, in the absence of sophisticated laboratory equipment. The method detection limit for PCBs in dimethyl sulfoxide (DMSO) extracts of sediment was 0.9 mg/kg. For PCBs in isopropanol extracts of fish tissue, the method detection limit was 0.6 mg/kg. The resolution of the ELISA was 0.83 mg/kg at 1.1 mg/kg and 1.6 mg/kg at 1.7 mg/kg, for sediment and fish tissue, respectively.
اظهر المزيد [+] اقل [-]Determination of atrazine in rainfall and surface water by enzyme immunoassay
1994
Dankwardt, A. (Technische Univ. Muenchen, Freising (Germany). Lehrstuhl fuer Botanik) | Wuest, S. | Elling, W. | Thurman, M. | Hock, B.
Rainwater and surface water from four sites in Germany (Bavaria and Lower Saxony) were analyzed for atrazine by enzyme immunoassay from June 1990 until October 1992. The limit of quantification of the immunoassay was 0.02 microgram per litre with a middle of the test at 0.2 microgram per litre. About 60% of the samples contained measurable amounts of atrazine. Seasonal trends were observed, with the highest concentration in the summer months of up to 4 microgram per litre for rainwater and up to 15 microgram per litre for surface waters. The highest concentrations were found in agricultural areas, while in the investigated national parks up to 0.56 microgram per litre could be detected in rain warer. This points to long-range atmospheric transport from agricultural areas to pristine national parks. Samples from forest stands usually showed higher atrazine concentrations than samples from open fields. Deposition rates of 10 - 50 microgram per m** (2) per year were observed in the national parks and 10 - 180 microgram per m** (2) per year at the agricultural sites. Comparison of results obtained by enzyme immunoassay and GC/MS showed a good correlation of r = 0.95.
اظهر المزيد [+] اقل [-]On-line speciation of arsenical compounds in fish and mussel extracts by HPLC-ICP-MS
1994
Caroli, S. (Istituto Superiore di Sanita, Rome (Italy)) | La Torre, F. | Petrucci, F. | Violante, N.
The separation and determination of sub-micromol per litre levels of six environmentally significant As compounds was accomplished by means of high performance liquid chromatography (HPLC) combined online with inductively coupled plasma mass spectrometry (ICP-MS). The species of interest (arsenite and arsenate, monomethylarsonic acid, dimethylarsinic acid, arsenobetaine and arsenocholine) were quantified in fish and mussel extracts after separation on a Dionex AS7 column equipped with an on-guard AG7 column using a bicarbonate buffer as the mobile phase in a gradient mode. The species thus eluted were directly forwarded to the ICP-MS detector. The detection power of the overall system allows each As form to be determined at concentrations as low a 0.0013 - 0.0027 micromol per litre.
اظهر المزيد [+] اقل [-]Potentials and limitations of field studies on forest decline associated with anthropogenic pollution
1989
Oren, R. | Werk, K.S. | Meyer, J. | Schulze, E.D.