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  • Gas chromatography  (56)
  • sediments  (44)
  • Springer  (100)
  • Blackwell Publishing Ltd
  • 1980-1984  (100)
  • 1925-1929
  • 1982  (74)
  • 1981  (26)
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  • 1980-1984  (100)
  • 1925-1929
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  • 1
    Digitale Medien
    Digitale Medien
    Chemically modified teflon wall-coated open tubular columns for gas chromatography (1981)
    Springer
    Chromatographia 14 (1981), S. 19-22 
    Details
    ISSN: 1612-1112
    Schlagwort(e): Teflon columns ; Chemically modified teflon ; Gas chromatography ; Capillary columns
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Summary Wall-coated open tubular columns prepared from chemically modified teflon tubing have been developed for gas chromatography. Chemical reaction of the inner walls of teflon tubing allows bonding of an adhesive layer on which a variety of stationary phaes can be coated. Test mixtures of alkanes and alcohols were used to investigate the chromatographic properties of these columns and the stability and mixing of the adhesive and stationary phae layers. the results in dicate that mixing of the layers is negligible and that the column is stable for a long period of time.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02262057
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  • 2
    Digitale Medien
    Digitale Medien
    Chemically modified teflon capillary columns for gas chromatography II. Solid surface effects in direct coated columns (1982)
    Springer
    Chromatographia 15 (1982), S. 641-644 
    Details
    ISSN: 1612-1112
    Schlagwort(e): Teflon capillary columns ; Chemically modified teflon ; Gas chromatography
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Summary The preparation of teflon capillary columns employing direct coating of the stationary phase to the chemically modified teflon surface and the role of the chemically modified teflon in the separation mechanism are described. Two types of contributions from the modified teflon have been observed: nonspecific adsorption of the carbon surface and specific interactions of polar groups in the carbon skeleton. The use of polar liquid phases can eliminate adsorption due to the presence of polar groups in the modified teflon.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02279491
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  • 3
    Digitale Medien
    Digitale Medien
    Die Herstellung von Glas-Kapillarsäulen für die Gas-Chromatographie (1981)
    Springer
    Chromatographia 14 (1981), S. 55-66 
    Details
    ISSN: 1612-1112
    Schlagwort(e): Capillary columns, glass ; Gas chromatography ; Column preparation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung Kapillar-Gas-Chromatographie ist heute das sich am stärksten entwickelnde Gebiet der Gas-Chromatographie. Es gibt viele komplexe, neue Fragestellungen in der Analytik, welche den Einsatz spezieller Kapillarsäulen erfordem. Glücklicherweise gibt es aber auch eine große Zahl von Herstellungsverfahren für Kapillarsäulen, welche — noch mehr als bei der Herstellung von gepackten Säulen — eine Anpassung an die gestellten Aufgaben ermöglichen. In diesem Artikel werden die Herstellungsverfahren für Kapillarsäulen zusammengestellt und Anregungen gegeben, wie aufgaben-orientierte Säulen erreicht werden.
    Notizen: Summary Glass capillary column chromatography is the most rapidly growing part of gas chromatography. There are many complex new analytical tasks and they require special capillary columns, Fortunately there is a wide range of column preparation methods available, and they make the preparation of glass capillary columns a more varied job than that of packed columns. In this paper these methods are reviewed and suggestions are given for making task-oriented columns.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02262064
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  • 4
    Digitale Medien
    Digitale Medien
    Gas chromatographic analysis of phenylurea herbicides following catalytic hydrolysis on silica gel (1981)
    Springer
    Chromatographia 14 (1981), S. 579-586 
    Details
    ISSN: 1612-1112
    Schlagwort(e): Gas chromatography ; Urea herbicides ; Catalytic hydrolysis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Summary A method is described for the rapid catalytic hydrolysis of phenylurea herbicides on silica gel at elevated temperatures. After derivatisation of the anilines produced with heptafluorobutyric acid anhydride final analysis is done on a gas chromatograph equipped with an electroncapture detector. Detection limits are in the 1–5 picogram range. The method has successfully been applied to residue analysis of water samples at the 1 ppb level. The determination of free anilines present in water samples and the potential of various techniques to be used to discriminate between free anilines and parent herbicides are also discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02262887
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  • 5
    Digitale Medien
    Digitale Medien
    Gas chromatographic analysis of water phenolic pollutants using acid-washed graphitised carbon black (1981)
    Springer
    Chromatographia 14 (1981), S. 86-88 
    Details
    ISSN: 1612-1112
    Schlagwort(e): Gas chromatography ; Graphitised carbon black ; Phenols ; Water pllutants
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Summary The fractionation of eleven phenols which may be contaminants in drinking water has been accomplished by using acid-washed graphitised carbon black modified with trimesic acid and PEG 20 M.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02279517
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  • 6
    Digitale Medien
    Digitale Medien
    Novel applications for headspace gas chromatography (1981)
    Springer
    Chromatographia 14 (1981), S. 447-451 
    Details
    ISSN: 1612-1112
    Schlagwort(e): Headspace analysis ; Gas chromatography ; Residual analysis of polyethylene terephthalate ; Acetylene reduction assay ; Ethylene evolution in germinating seed ; Acetaldehyde generation in polyester resin
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Summary New application areas for headspace gas chromatography in agricultural and polymer degradation research are described. Specific examples are drawn from the various forms of headspace analysis with emphasis on the automated static equilibrium method.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02263531
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  • 7
    Digitale Medien
    Digitale Medien
    Derivatization of amines with chloroformate esters for gas chromatographic analysis (1982)
    Springer
    Chromatographia 16 (1982), S. 60-62 
    Details
    ISSN: 1612-1112
    Schlagwort(e): Gas chromatography ; Amines ; Derivatization ; Chloroformate esters
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Summary The gas chromatographic analysis of amines after conversion to electron capture sensitive carbamates in two-phase systems has been studied. Hydrophilic compounds, for instance methylamine, are reacted with 2,2,2-trichloro-tert. butyl chloroformate. Quantitation below 10−7 M can be made by thermionic or electron capture detection. A hydrophobic amine, namely N,N-dimethyl-n-octylamine, was derivatized with 2,4,6-tribromophenyl chloroformate with addition of iodide ion to the aqueous phase. The favorable effect of iodide ion as well as the choice of pH and chloroformate ester is discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02258870
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  • 8
    Digitale Medien
    Digitale Medien
    Gas chromatography in open rectangular channels with large aspect ratios (1982)
    Springer
    Chromatographia 16 (1982), S. 98-102 
    Details
    ISSN: 1612-1112
    Schlagwort(e): Gas chromatography ; Rectangular channel ; Efficiency ; Capacity
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Summary Gas chromatographic experiments have been performed in a truly rectangular channel with a 60∶1 cross-sectional aspect ratio, constructed according to the field-flow fractionation technology. It is shown that the peak broadening is controlled by the thickness of the channel while the maximum load is determined by the largest cross-sectional dimension. However, even with its elongated configuration, the side walls contribute significantly to the band broadening of solutes with a high diffusivity. Good agreement is found between the experimental plate height data and the recent theoretical calculations of Golay [13] taking into account the side-wall effect.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02258877
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  • 9
    Digitale Medien
    Digitale Medien
    The study of phosphorus and nitrogen fluxes in enriched isolation columns (1981)
    Springer
    Hydrobiologia 77 (1981), S. 49-60 
    Details
    ISSN: 1573-5117
    Schlagwort(e): Phosphorus ; sediments ; isolation columns ; nutrient enrichment ; enclosures
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Isolation columns positioned in approximately 3.5 m of water in Midmar Dam, were enriched with PO4-P and NO3-N, singly and in combination. Increased chlorophyll concentration resulted from all enrichment treatments. Responses showed marked seasonality and varied in intensity and duration. Despite the PO4-P fixing potential of the sediments, SRP concentrations increased markedly at times and possible reasons for this discussed. The marked response to addition of NO3-N alone suggested a flux of phosphorus from the sediment through the water to the algal component. The significance of periphyton within the columns is discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00006387
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  • 10
    Digitale Medien
    Digitale Medien
    Experimental measurement of sediment nitrification and denitrification in Hamilton Harbour, Canada (1982)
    Springer
    Hydrobiologia 91-92 (1982), S. 207-216 
    Details
    ISSN: 1573-5117
    Schlagwort(e): sediments ; water column ; nitrification ; denitrification ; experiments ; modelling
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract This research examines the role of sediment nitrification and denitrification in the nitrogen cycle of Hamilton Harbour. The Harbour is subject to large ammonia and carbon loadings from a waste-water treatment plant and from steel industries. Spring ammonia concentrations rapidly decrease from 4.5 to 0.5 mg 1−1, while spring nitrate concentrations increase from 1 to 2 mg l−1, by mid-summer. A three-layer sediment model was developed. The first layer is aerobic; in it, oxidation of organics and nitrification occurs. The second layer is for denitrification, and the third layer is for anaerobic processes. Ammonia sources for nitrification include diffusion from the water column, sources associated with the oxidation of organics, sources from denitrification and from anaerobic processes. Diffusion of oxygen, ammonia and nitrate across the sediment-water interface occurs. Temperature effects are modelled using the Arrhenius concept. A combination of zero-order kinetics for nitrate or ammonia consumption with diffusion results in a half-order reaction, with respect to the water column loss rate to sediments. From experimental measurement, the rate of nitrification is 200 mg N 1−1 sediment per day, while that of denitrification is 85 mg N 1–1 sediment per day at 20 °C. The Arrhenius activation energy is estimated as 15 000 cal/ mole-K and 17 000 cal/ mole-K for nitrification and denitrification, respectively, between 10 °C and 20 °C. Calculations of the flux of ammonia with the sediments, using the biofilm model, compare favourably with experimental observations. The ammonia flux from the water column is estimated to account for 20% of the observed decrease in water column stocks of ammonia, while the nitrate flux from the water column is estimated to account for 25% of the total nitrogen produced by the sediments.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00940111
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  • 11
    Digitale Medien
    Digitale Medien
    Particle size distribution and chemical parameters of the sediments of a shallow turbid impoundment (1982)
    Springer
    Hydrobiologia 91-92 (1982), S. 341-353 
    Details
    ISSN: 1573-5117
    Schlagwort(e): Impoundment ; sediments ; particle size ; major ions ; nutrients ; cation exchange
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract As part of an ecosystem study of a small mesotrophic turbid impoundment in the semi-arid part of South Africa, an investigation was made of the particle size distribution, organic content and inorganic chemical composition of the sediment. Nine transects 50 m apart were made during February 1980. Sediments were sampled with an Eckman grab. The following analyses were made: size fractionation by wet sieving, cation exchange capacity, exchangeable Na, K, Ca, Mg and PO4, total P, and loss on ignition. From the results it was clear that the finer particles, in or near the original river bed, had higher cation exchange capacity, total P, exchangeable phosphorus and organic content. Littoral areas with avian habitat and extensive macrophyte vegetation, contained coarser sediments. Organic detritus apparently migrated to the deeper part of the impoundment. Sediments of lacustrine and fluvial origin were identified by means of the Passega classification.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00940124
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  • 12
    Digitale Medien
    Digitale Medien
    Spatial heterogeneity in whole lake sediments — towards a loading estimate (1982)
    Springer
    Hydrobiologia 91-92 (1982), S. 235-240 
    Details
    ISSN: 1573-5117
    Schlagwort(e): sediments ; nutrients ; loading estimates
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Studies of nutrient loadings, to shallow culturally eutrophied Alberta lakes, suggest internal inputs are significant. In this regard, estimation of bottom sediment P loads to Lake Wabamun (80 km2, 5.5 m $$\bar x$$ depth) were examined. Initially we determined the spatial variability in Total Organic Content (% loss on ignition) and Total Phosphorus, as indicators. Phosphorus fractions and biologically available phosphorus (BAP) were measured at specific stations. These data showed a very uniform distribution in sediment type with a Total Organic Content of 40.6 ± 3.3 (95% C.L.) at the west end, gradually declining to 26.3 ± 0.9 at the east end. Transects performed at routine monitoring stations indicate the representativeness of each station, e.g., station 2, 40.8 ± 1.3 (10 sites). One explanation of this uniformity is provided from210Pb analysis of shallow cores which indicate mixing to a depth of 16 cm. This is also thought to explain the mechanics of P loading to the water phase. Finally, Total Organic Content relates well to BAP (r2 = 0.80). It is hoped that this simple technique may well permit more precise extrapolation to whole lake BAP estimates at least on this lake.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00940114
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  • 13
    Digitale Medien
    Digitale Medien
    Distribution and concentrations of naturally-occurring radionuclides in sediments in a uranium mining area of northern Saskatchewan, Canada (1982)
    Springer
    Hydrobiologia 91-92 (1982), S. 355-361 
    Details
    ISSN: 1573-5117
    Schlagwort(e): sediments ; uranium ; radium ; radionuclides ; models
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Uranium mining and milling operations can contribute to environmental degradation through the increased release of naturally-occurring radionuclides. However, studies of the interactions of these radionuclides with freshwater sediments have been limited. The present study examined the vertical distribution of uranium, thorium, radium-226, polonium-210 and lead-210 in undisturbed sediment cores collected in the vicinity of mining, milling and exploration activities. Uranium levels in surface sediments ranged from 1.9 to 5650 µg g−1, Ra-226 from 〈0.1 to 480 pCi g−1 and Pb-210 from 0.8 to 931 pCi g−1 in the samples reported here, with the highest values occurring downstream of waste rock disposal areas. Concentrations usually decreased with depth, and there was little evidence of any strong effect of bioturbation on radionuclide profiles at the scale examined here. Mathematical models of uranium and radium-226 adsorption on and movement into the sediment were constructed, based on expected adsorption coefficients and estimated loading. The model predictions of radionuclide distribution with depth were qualitatively similar to those actually measured, but the predicted concentrations were generally lower than those observed, both in unaffected areas and in areas adjacent to uranium extraction activities.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00000035
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  • 14
    Digitale Medien
    Digitale Medien
    Lake sediments as recorders of geomagnetic field variations — applications to dating post-Glacial sediments (1982)
    Springer
    Hydrobiologia 91-92 (1982), S. 587-596 
    Details
    ISSN: 1573-5117
    Schlagwort(e): dating ; sediments ; geomagnetic variations
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Field and laboratory methods, developed to recover the record of past secular variations of geomagnetic declination and inclination carried by the remanent magnetization of some lake sediments, are described. Type curves, delineating these parameters through post-Glacial time, have now been constructed for Europe and east-central N. America. These curves, once established for any region, are useful for dating lake sediments from that region. The principal inclination features exhibited by the European curves can also be identified along the N. American curves with a delay of some 600 years, on average.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02391973
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  • 15
    Digitale Medien
    Digitale Medien
    Stratigraphic and dynamic effects of sediment reworking by Great Lakes zoobenthos (1982)
    Springer
    Hydrobiologia 91-92 (1982), S. 611-622 
    Details
    ISSN: 1573-5117
    Schlagwort(e): zoobenthos ; Great Lakes ; sediments ; radionuclides
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Recent sediments of the North American Great Lakes are inhabited by numerous species of macrobenthos which alter the physical and chemical properties of sediments and modify interface transport characteristics. Distributions of such radionuclides as cesium-137, lead-210, and isotopes of plutonium exhibit a zone of constant activity extending down from the sediment-water interface from 1 to 15 cm. Recent studies have confirmed that radiometrically determined mixed depths are consistent with the vertical distribution of oligochaete worms and the amphipod,Pontoporeia hoyi. Generally, 90% of the benthos are contained within the radiometrically defined mixed zone. Where comparisons are possible, rates of sediment reworking by ‘conveyor belt’ species are comparable to or exceed sedimentation rates. Systematic variations in the mixed depth occur within depositional basins with greatest depths tending to be associated with least consolidated, organically rich materials. A quantitative steady-state mixing model accounts satisfactorily for observed radioactivity and heavy metal profiles. Bioturbation appears to be an important process, limiting the resolution with which historical records of particle-associated contaminants may be reconstructed from sediment cores. As bioturbation serves to maintain contact of contaminated sediments with overlying water, this time may also characterize the long-term lake recovery for contaminants removed by burial. As the time varies with location, a mean for an entire lake is not well known, but is on the order of 20 years for Lake Huron.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02391976
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  • 16
    Digitale Medien
    Digitale Medien
    Chemistry and plant ecology of zinc-rich wastes dominated by blue-green algae (1981)
    Springer
    Hydrobiologia 83 (1981), S. 331-341 
    Details
    ISSN: 1573-5117
    Schlagwort(e): zinc ; tailings ; water ; sediments ; blue-green algae (cyanobacteria) ; protonema ; stromatolite ; diel change
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract An account is given of the chemistry and vegetation of wet areas below the Elvins tailings pile in the Old Lead Belt of Missouri. Zinc in particular is present at highly elevated levels in the water (5.9–21.0 mg l−1) and most sediments. The two most widespread plants are a blue-green alga,Plectonema gracillimum, and a moss,Dicranella sp. In wetter areas the latter exists predominantly as protonema.Plectonema and the protonema typically grow in very close association, although situations do occur where only one or the other is present. For instance, algal flocs in two permanent ponds consisted largely ofPlectonema and unicellular blue-green algae, with a few eukaryotic algae, but no protonema. Other dominants in the area areEleocharis sp.,Scirpus americanus andTypha latifolia. One seepage was studied in more detail; it showed marked changes in both chemistry and vegetation on passing from source to a site 15 m downstream. Aqueous Zn dropped from 21 to 8 mg l−1. ThePlectonema-Dicranella protonema community predominated in the upper part, developing a laminated structure up to 3 cm thick (justifying recognition as a stromatolite). Further downstream a white crust including much hydrozincite and with a very high overall zinc content (c. 370 mg g−1 Zn) was deposited over the green layer, making it endolithic in position, though probably not in origin. Still further downstream the green layer disappeared, leaving only a hard white crust. A discussion is included of the extent to which observed variations in the zinc content of water and sediments below the tailings pile are influenced by living and dead plants. An apparent diel cycle in aqueous zinc at some sites is of particular interest, as it was not matched by changes in Ca or Cd.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00008284
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  • 17
    Digitale Medien
    Digitale Medien
    Transport of iron and manganese in relation to the shapes of their concentration-depth profiles (1982)
    Springer
    Hydrobiologia 91-92 (1982), S. 463-471 
    Details
    ISSN: 1573-5117
    Schlagwort(e): iron ; manganese ; sediments ; water ; transport ; model
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract A model is presented which describes the transport of iron and manganese in the vicinity of a redox boundary. It is based on input of a particulate component, to form a point source, from which soluble species diffuse along a concentration gradient. The shapes of concentration-depth profiles in marine and freshwater sediments and water columns are reviewed and discussed in terms of the model. Transport, either entirely within a water column or within the sediment, may be simply treated because the rate of vertical transport can be regarded as constant. The discontinuity in the rate of vertical transport which occurs at the sediment-water interface can provide a complicated example of the model, especially when it coincides with the redox boundary. Authigenic mineral formation processes can modify the model, sometimes to such an extent that it becomes invalid. This is particularly true for soluble iron profiles in organically rich marine sediments. Sampling interval is critical to the resultant profile shape and must be relevant to the particular environment, e.g. metres in water columns and millimetres in sediments. The differences in the rates of reduction and oxidation of iron and manganese tend to modify both the position of the profile with respect to the redox-cline and its stage of development in a seasonally anoxic system. It is these factors which determine why most of the iron which reaches a sediment is permanently incorporated whereas manganese is re-released. This mechanism determines the average ratio of iron to manganese in sedimentary rocks. The development of peaked profile shapes in water columns implies that under certain conditions dissolved iron and manganese may be transported from the water column to the pore waters of the sediment.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00000044
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  • 18
    Digitale Medien
    Digitale Medien
    Deepwater sediments and trophic conditions in Florida lakes (1982)
    Springer
    Hydrobiologia 91-92 (1982), S. 597-602 
    Details
    ISSN: 1573-5117
    Schlagwort(e): eutrophication ; diagenesis ; sediments ; nitrogen
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Sediment cores were taken from near maximum depth in 15 Florida lakes representing a wide range of trophic conditions. Chemical analyses of surface sediments showed Al, Fe, and Ca to be the most abundant elements in all samples, and the ratio of Al to Ca to be smaller for eutrophic lakes. Sediment organic matter increased with trophic state, as did the degree to which it was enriched in nitrogen. Corresponding sediment C/N ratios decreased with increasing lake trophic state and showed significant negative correlation with chlorophyll a, total N, and total P in the water column. Concentrations of sedimentary chlorophyll derivatives showed some relation to trophic state but differences in basin morphometry hinder its use as an inter-lake index of chlorophyll production.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00000058
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  • 19
    Digitale Medien
    Digitale Medien
    Experimental measurement of sediment nitrification and denitrification in Hamilton Harbour, Canada (1982)
    Springer
    Hydrobiologia 91-92 (1982), S. 207-216 
    Details
    ISSN: 1573-5117
    Schlagwort(e): sediments ; water column ; nitrification ; denitrification ; experiments ; modelling
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract This research examines the role of sediment nitrification and denitrification in the nitrogen cycle of Hamilton Harbour. The Harbour is subject to large ammonia and carbon loadings from a waste-water treatment plant and from steel industries. Spring ammonia concentrations rapidly decrease from 4.5 to 0.5 mg 1−1, while spring nitrate concentrations increase from 1 to 2 mg l−1, by mid-summer. A three-layer sediment model was developed. The first layer is aerobic; in it, oxidation of organics and nitrification occurs. The second layer is for denitrification, and the third layer is for anaerobic processes. Ammonia sources for nitrification include diffusion from the water column, sources associated with the oxidation of organics, sources from denitrification and from anaerobic processes. Diffusion of oxygen, ammonia and nitrate across the sediment-water interface occurs. Temperature effects are modelled using the Arrhenius concept. A combination of zero-order kinetics for nitrate or ammonia consumption with diffusion results in a half-order reaction, with respect to the water column loss rate to sediments. From experimental measurement, the rate of nitrification is 200 mg N 1−1 sediment per day, while that of denitrification is 85 mg N 1–1 sediment per day at 20 °C. The Arrhenius activation energy is estimated as 15 000 cal/ mole-K and 17 000 cal/ mole-K for nitrification and denitrification, respectively, between 10 °C and 20 °C. Calculations of the flux of ammonia with the sediments, using the biofilm model, compare favourably with experimental observations. The ammonia flux from the water column is estimated to account for 20% of the observed decrease in water column stocks of ammonia, while the nitrate flux from the water column is estimated to account for 25% of the total nitrogen produced by the sediments.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02391937
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  • 20
    Digitale Medien
    Digitale Medien
    Introduction (1982)
    Springer
    Hydrobiologia 91-92 (1982), S. 1-1 
    Details
    ISSN: 1573-5117
    Schlagwort(e): symposium ; sediments ; freshwater
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00940091
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  • 21
    Digitale Medien
    Digitale Medien
    Transport of iron and manganese in relation to the shapes of their concentration-depth profiles (1982)
    Springer
    Hydrobiologia 91-92 (1982), S. 463-471 
    Details
    ISSN: 1573-5117
    Schlagwort(e): iron ; manganese ; sediments ; water ; transport ; model
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract A model is presented which describes the transport of iron and manganese in the vicinity of a redox boundary. It is based on input of a particulate component, to form a point source, from which soluble species diffuse along a concentration gradient. The shapes of concentration-depth profiles in marine and freshwater sediments and water columns are reviewed and discussed in terms of the model. Transport, either entirely within a water column or within the sediment, may be simply treated because the rate of vertical transport can be regarded as constant. The discontinuity in the rate of vertical transport which occurs at the sediment-water interface can provide a complicated example of the model, especially when it coincides with the redox boundary. Authigenic mineral formation processes can modify the model, sometimes to such an extent that it becomes invalid. This is particularly true for soluble iron profiles in organically rich marine sediments. Sampling interval is critical to the resultant profile shape and must be relevant to the particular environment, e.g. metres in water columns and millimetres in sediments. The differences in the rates of reduction and oxidation of iron and manganese tend to modify both the position of the profile with respect to the redox-cline and its stage of development in a seasonally anoxic system. It is these factors which determine why most of the iron which reaches a sediment is permanently incorporated whereas manganese is re-released. This mechanism determines the average ratio of iron to manganese in sedimentary rocks. The development of peaked profile shapes in water columns implies that under certain conditions dissolved iron and manganese may be transported from the water column to the pore waters of the sediment.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02391960
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  • 22
    Digitale Medien
    Digitale Medien
    Deepwater sediments and trophic conditions in Florida lakes (1982)
    Springer
    Hydrobiologia 91-92 (1982), S. 597-602 
    Details
    ISSN: 1573-5117
    Schlagwort(e): eutrophication ; diagenesis ; sediments ; nitrogen
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Sediment cores were taken from near maximum depth in 15 Florida lakes representing a wide range of trophic conditions. Chemical analyses of surface sediments showed Al, Fe, and Ca to be the most abundant elements in all samples, and the ratio of Al to Ca to be smaller for eutrophic lakes. Sediment organic matter increased with trophic state, as did the degree to which it was enriched in nitrogen. Corresponding sediment C/N ratios decreased with increasing lake trophic state and showed significant negative correlation with chlorophylla, total N, and total P in the water column. Concentrations of sedimentary chlorophyll derivatives showed some relation to trophic state but differences in basin morphometry hinder its use as an inter-lake index of chlorophyll production.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02391974
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  • 23
    Digitale Medien
    Digitale Medien
    Microbial metabolism in surface sediments and its role in the immobilization of phosphorus in oligotrophic lake sediments (1982)
    Springer
    Hydrobiologia 91-92 (1982), S. 261-268 
    Details
    ISSN: 1573-5117
    Schlagwort(e): microbial metabolism ; phosphorus ; sediments ; oligotrophic lake
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Rapid microbial metabolism and a large phosphorus uptake potential were observed in surface sediments of Lake George, New York. This sediment (termed the flocculent layer) also exhibited a phosphorus limited condition and a large reservoir of inorganic phosphorus associated with humic substances. These observations suggest that the empirically observed phosphorus retention in oligotrophic lake sediments may be promoted by a rapid cycling of phosphorus between microflora and its associated organic matter.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02391943
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  • 24
    Digitale Medien
    Digitale Medien
    Standardization of methods of analysis for heavy metals in sediments (1982)
    Springer
    Hydrobiologia 91-92 (1982), S. 689-695 
    Details
    ISSN: 1573-5117
    Schlagwort(e): standardization ; heavy metals ; sediments ; base-line levels ; chemical partition
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract In studies of heavy metals in sediments, there is a need for standardization of the procedures for sample collection and preservation, chemical analyses and presentation of results. The method and depth of sampling depend on the aim of the investigation and on local sediment conditions, such as consistency of the sediment, rate of sedimentation, diagnetic processes and bioturbation. Therefore no general recommendations can be given in this respect. During collection and preservation, contamination and loss of constituents ust be avoided. In sediments, the best means for estimating total contents of metals is digestion with HF, in combination with strong acids. Other methods include X-ray fluorescence and neutron activation analyses. The use of HF is considered objectionable by some laboratories. A reasonable alternative is aqua regia. Because variations in granular composition affect metal contents, it is advisable to use the fraction 〈 63 μm for the analysis. Chemical partition of sediments provides an insight into the source of metallic constituents, and their pathways to deposition areas. A three-step extraction procedure, in the sequence 0.1 M hydroxylamine-HCl, H2O2 30% and HF, is proposed. Finally, attention is paid to the anthropogenic enrichment of metals in sediments. The establishment of base-line levels is discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00940158
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  • 25
    Digitale Medien
    Digitale Medien
    Zinc in water and sediments of two finnish lakes (1982)
    Springer
    Hydrobiologia 91-92 (1982), S. 155-160 
    Details
    ISSN: 1573-5117
    Schlagwort(e): heavy metals ; zinc ; lakes ; sediments ; pollution ; industrial load ; sedimentation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The distribution of zinc in Lake Vanajavesi and Lake Mallasvesi, South Finland, was determined on the basis of water and sediment studies. Lake Vanajavesi is one of the most polluted of large inland lakes, in Finland. The zinc load comes mainly from industrial sources. Lake Mallasvesi, situated near Vanajavesi, is in almost natural condition. The water samples were taken by a Ruttner sampler. In collecting sediment samples, a freezing technique was used. The results of zinc analyses indicate that, during several winters, zinc has spread with waste water to different parts of L. Vanaja against the main course of flow. A close correlation between sedimentation of zinc and waste discharge from a textile factory was found in the present study.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02391931
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  • 26
    Digitale Medien
    Digitale Medien
    Standardization of methods of analysis for heavy metals in sediments (1982)
    Springer
    Hydrobiologia 91-92 (1982), S. 689-695 
    Details
    ISSN: 1573-5117
    Schlagwort(e): standardization ; heavy metals ; sediments ; base-line levels ; chemical partition
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract In studies of heavy metals in sediments, there is a need for standardization of the procedures for sample collection and preservation, chemical analyses and presentation of results. The method and depth of sampling depend on the aim of the investigation and on local sediment conditions, such as consistency of the sediment, rate of sedimentation, diagnetic processes and bioturbation. Therefore no general recommendations can be given in this respect. During collection and preservation, contamination and loss of constituents ust be avoided. In sediments, the best means for estimating total contents of metals is digestion with HF, in combination with strong acids. Other methods include X-ray fluorescence and neutron activation analyses. The use of HF is considered objectionable by some laboratories. A reasonable alternative is aqua regia. Because variations in granular composition affect metal contents, it is advisable to use the fraction 〈 63 μm for the analysis. Chemical partition of sediments provides an insight into the source of metallic constituents, and their pathways to deposition areas. A three-step extraction procedure, in the sequence 0.1 M hydroxylamine-HCl, H2O2 30% and HF, is proposed. Finally, attention is paid to the anthropogenic enrichment of metals in sediments. The establishment of base-line levels is discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02391984
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  • 27
    Digitale Medien
    Digitale Medien
    Comparison of sediment energy-texture relationships in marine and lacustrine environments (1982)
    Springer
    Hydrobiologia 91-92 (1982), S. 71-84 
    Details
    ISSN: 1573-5117
    Schlagwort(e): sediments ; lakes ; seas ; oceans ; energy relationships ; population statistics
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Sediments in the marine environment are generally subject to higher energy levels than those of lake systems, and lakes are virtually unaffected by tidal range which modifies beach structures formed in response to wave effects. However, despite different energy levels, the textural characteristics of both marine and lacustrine sediments are very similar. The main difference between marine and lacustrine facies is the depth range over which these characteristics remain consistent. In lakes, depth limitation may influence the development of surface waves and restrict textural distributions. Simple textural relationships can be used to describe comparable marine and lacustrine sedimentary conditions. Sediments which have been altered by post-depositional erosion, such as lag deposits, or by ice-drop or wind blown settlement, show comparable textural modifications. The settlement of silt and clay size particulates, in the marine environment and lakes, may differ slightly because of the chemical differences between salt and fresh water.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00940097
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  • 28
    Digitale Medien
    Digitale Medien
    The fractionation of iron-phosphorus compounds in sediments studied by Mössbauer spectroscopy (1982)
    Springer
    Hydrobiologia 91-92 (1982), S. 697-700 
    Details
    ISSN: 1573-5117
    Schlagwort(e): sediments ; Mössbauer spectroscopy ; iron ; phosphorus ; geochemistry ; analysis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Iron compounds of phosphorus form a large part of the phosphorus bound in sediments. Mössbauer spectroscopy is a technique that enables us to study, directly, chemical forms of iron in solid samples. Mössbauer spectroscopy allowed us to check, directly, the selectivity of the extraction scheme for soil phosphorus proposed by Chang & Jackson (1957), but only as far as the iron compounds are concerned. It appears that selectivity of the extraction method leaves much to be desired.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00940159
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  • 29
    Digitale Medien
    Digitale Medien
    Model for instream regulation of radioisotopes and heavy metals in riverine waters subjected to a uranium mill discharge (1982)
    Springer
    Hydrobiologia 91-92 (1982), S. 175-188 
    Details
    ISSN: 1573-5117
    Schlagwort(e): simulation ; sediments ; radioisotopes ; heavy metals
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract In the Athabaska sandstone region of northern Saskatchewan, mining and milling of uranium-bearing ore is subjecting, and will continue to subject, surface waters to inputs of soluble heavy metals and uranium and thorium decay series radioisotopes. A mathematical simulation model was developed to assess the role of riverine sediments in regulating soluble concentrations of heavy metals and radioisotopes released to the environment through treated mining and milling process effluents. Specific elements studied included As, Ni, Pb, U, and Ra-226. The model considered that diffusion into sediment porewater and adsorption by sediment particulates from sediment porewater were the two dominant mechanisms regulating sediment loading. Experiments indicated that the equilibrium adsorption behaviour of the heavy metals and radioisotopes studied could be adequately explained using a linear adsorption isotherm, over the range of concentrations expected in the environment. Experimentally determined linear isotherm slopes ranged from 200 ml g−1 to 21 000 ml gl. Diffusion into the effective depth of the sediments (20 cm) was modelled using a quadratic (second order) driving force and a corresponding mass transfer coefficient. The model coefficients were calibrated using field and laboratory data. Results of the modelling suggested that the sediments have a small effect on instream concentrations during the active phases of mining and milling. The sediments were predicted to accumulate sufficient adsorbed mass, during the operational phase of mining and milling, to act as a distributed instream source after completion of milling activities. The significance of this post-operational source was a function of the initial effluent loading, elapsed time and site specific river characteristics.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00940108
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  • 30
    Digitale Medien
    Digitale Medien
    Microbial metabolism in surface sediments and its role in the immobilization of phosphorus in oligotrophic lake sediments (1982)
    Springer
    Hydrobiologia 91-92 (1982), S. 261-268 
    Details
    ISSN: 1573-5117
    Schlagwort(e): microbial metabolism ; phosphorus ; sediments ; oligotrophic lake
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Rapid microbial metabolism and a large phosphorus uptake potential were observed in surface sediments of Lake George, New York. This sediment (termed the flocculent layer) also exhibited a phosphorus limited condition and a large reservoir of inorganic phosphorus associated with humic substances. These observations suggest that the empirically observed phosphorus retention in oligotrophic lake sediments may be promoted by a rapid cycling of phosphorus between microflora and its associated organic matter.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00940117
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  • 31
    Digitale Medien
    Digitale Medien
    Distribution and concentrations of naturally-occurring radionuclides in sediments in a uranium mining area of northern Saskatchewan, Canada (1982)
    Springer
    Hydrobiologia 91-92 (1982), S. 355-361 
    Details
    ISSN: 1573-5117
    Schlagwort(e): sediments ; uranium ; radium ; radionuclides ; models
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Uranium mining and milling operations can contribute to environmental degradation through the increased release of naturally-occurring radionuclides. However, studies of the interactions of these radionuclides with freshwater sediments have been limited. The present study examined the vertical distribution of uranium, thorium, radium-226, polonium-210 and lead-210 in undisturbed sediment cores collected in the vicinity of mining, milling and exploration activities. Uranium levels in surface sediments ranged from 1.9 to 5650 µg g−1, Ra-226 from 〈0.1 to 480 pCi g−1 and Pb-210 from 0.8 to 931 pCi g−1 in the samples reported here, with the highest values occurring downstream of waste rock disposal areas. Concentrations usually decreased with depth, and there was little evidence of any strong effect of bioturbation on radionuclide profiles at the scale examined here. Mathematical models of uranium and radium-226 adsorption on and movement into the sediment were constructed, based on expected adsorption coefficients and estimated loading. The model predictions of radionuclide distribution with depth were qualitatively similar to those actually measured, but the predicted concentrations were generally lower than those observed, both in unaffected areas and in areas adjacent to uranium extraction activities.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00940125
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  • 32
    Digitale Medien
    Digitale Medien
    Distribution and concentrations of naturally-occurring radionuclides in sediments in a uranium mining area of northern Saskatchewan, Canada (1982)
    Springer
    Hydrobiologia 91-92 (1982), S. 355-361 
    Details
    ISSN: 1573-5117
    Schlagwort(e): sediments ; uranium ; radium ; radionuclides ; models
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Uranium mining and milling operations can contribute to environmental degradation through the increased release of naturally-occurring radionuclides. However, studies of the interactions of these radionuclides with freshwater sediments have been limited. The present study examined the vertical distribution of uranium, thorium, radium-226, polonium-210 and lead-210 in undisturbed sediment cores collected in the vicinity of mining, milling and exploration activities. Uranium levels in surface sediments ranged from 1.9 to 5650 µg g−1, Ra-226 from 〈0.1 to 480 pCi g−1 and Pb-210 from 0.8 to 931 pCi g−1 in the samples reported here, with the highest values occurring downstream of waste rock disposal areas. Concentrations usually decreased with depth, and there was little evidence of any strong effect of bioturbation on radionuclide profiles at the scale examined here. Mathematical models of uranium and radium-226 adsorption on and movement into the sediment were constructed, based on expected adsorption coefficients and estimated loading. The model predictions of radionuclide distribution with depth were qualitatively similar to those actually measured, but the predicted concentrations were generally lower than those observed, both in unaffected areas and in areas adjacent to uranium extraction activities.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02391951
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  • 33
    Digitale Medien
    Digitale Medien
    The fractionation of iron-phosphorus compounds in sediments studied by Mössbauer spectroscopy (1982)
    Springer
    Hydrobiologia 91-92 (1982), S. 697-700 
    Details
    ISSN: 1573-5117
    Schlagwort(e): sediments ; Mössbauer spectroscopy ; iron ; phosphorus ; geochemistry ; analysis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Iron compounds of phosphorus form a large part of the phosphorus bound in sediments. Mössbauer spectroscopy is a technique that enables us to study, directly, chemical forms of iron in solid samples. Mössbauer spectroscopy allowed us to check, directly, the selectivity of the extraction scheme for soil phosphorus proposed by Chang & Jackson (1957), but only as far as the iron compounds are concerned. It appears that selectivity of the extraction method leaves much to be desired.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02391985
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  • 34
    Digitale Medien
    Digitale Medien
    Spatial heterogeneity in whole lake sediments — towards a loading estimate (1982)
    Springer
    Hydrobiologia 91-92 (1982), S. 235-240 
    Details
    ISSN: 1573-5117
    Schlagwort(e): sediments ; nutrients ; loading estimates
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Studies of nutrient loadings, to shallow culturally eutrophied Alberta lakes, suggest internal inputs are significant. In this regard, estimation of bottom sediment P loads to Lake Wabamun (80 km2, 5.5 m $$\bar x$$ depth) were examined. Initially we determined the spatial variability in Total Organic Content (% loss on ignition) and Total Phosphorus, as indicators. Phosphorus fractions and biologically available phosphorus (BAP) were measured at specific stations. These data showed a very uniform distribution in sediment type with a Total Organic Content of 40.6 ± 3.3 (95% C.L.) at the west end, gradually declining to 26.3 ± 0.9 at the east end. Transects performed at routine monitoring stations indicate the representativeness of each station, e.g., station 2, 40.8 ± 1.3 (10 sites). One explanation of this uniformity is provided from210Pb analysis of shallow cores which indicate mixing to a depth of 16 cm. This is also thought to explain the mechanics of P loading to the water phase. Finally, Total Organic Content relates well to BAP (r2 = 0.80). It is hoped that this simple technique may well permit more precise extrapolation to whole lake BAP estimates at least on this lake.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02391940
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  • 35
    Digitale Medien
    Digitale Medien
    An investigation into some physical and biotic effects of flooding on reservoir mud previously subjected to a period of aerial exposure (1982)
    Springer
    Hydrobiologia 97 (1982), S. 27-35 
    Details
    ISSN: 1573-5117
    Schlagwort(e): Hong Kong ; man-made lake ; marginal zone ; sediments ; Melanoides tuberculata ; freshwater gastropods ; allochthonous ; water-level fluctuations
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract A series of laboratory experiments were carried out in order to investigate the effects of selected physical and biotic processes on the substratum of a recently flooded gently sloping marginal zone of Plover Cove Reservoir, Hong Kong. The physical effects of disturbance of the sediments promoted the redistribution of organic matter, as shown by differences in the percentage of organic matter in the supernatant and residue resulting when reservoir mud was stirred. It is suggested that such a process would promote the transfer of allochthonous organic carbon from the marginal zone (the area of input of such material) to the rest of the water body. Substrate characteristics were also influenced by the activities of two species of benthic gastropod,Sinotaia quadrata andMelanoides tuberculata. These animals increased the rate of production of particles from soaked blocks of parent mud when compared with experimental treatments in the absence of snails. Additionally both species enhanced the production of aggregates from fine sediments with a particle size of less than 125 µm. The magnitudes of both processes were statistically significant. Laboratory observations showed thatM. tuberculata had a significantly faster rate of aggregate and fine particulate production thanS. quadrata and it is possible that the former species may have the capacity to modify the substrate characteristics of the newly flooded marginal zone of Plover Cove.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00014957
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  • 36
    Digitale Medien
    Digitale Medien
    Effect of artificial destratification on iron, manganese, and zinc in the water, sediments, and two species of benthic macroinvertebrates in an Oklahoma lake (1982)
    Springer
    Hydrobiologia 87 (1982), S. 11-16 
    Details
    ISSN: 1573-5117
    Schlagwort(e): lake stratification ; artificial destratification ; lake mixing ; heavy metals ; sediments ; benthic macroinvertebrates
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Ham's Lake was destratified in the summers of 1977 and 1978 by pumping surface water to the bottom. However, an arm was prevented from mixing by a submerged dam of a former farm pond and remained stratified. The concentration of manganese in the water increased to over 5 000 µg 1−1 in the hypolimnion of the anoxic arm in summer. Soluble manganese averaged 28% of total concentration. Total iron concentrations were relatively high in the water and sorbed iron values were extremely low in the sediments. Soluble iron averaged 12% of total concentration. Zinc values were low in the water and sediments. Chaoborus punctipennis and Chironomus riparius concentrated iron and zinc and discriminated against manganese. Concentration factors were unaffected by mixing.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00016657
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  • 37
    Digitale Medien
    Digitale Medien
    The fractionation of iron-phosphorus compounds in sediments studied by Mössbauer spectroscopy (1982)
    Springer
    Hydrobiologia 91-92 (1982), S. 697-700 
    Details
    ISSN: 1573-5117
    Schlagwort(e): sediments ; Mössbauer spectroscopy ; iron ; phosphorus ; geochemistry ; analysis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Iron compounds of phosphorus form a large part of the phosphorus bound in sediments. Mössbauer spectroscopy is a technique that enables us to study, directly, chemical forms of iron in solid samples. Mössbauer spectroscopy allowed us to check, directly, the selectivity of the extraction scheme for soil phosphorus proposed by Chang & Jackson (1957), but only as far as the iron compounds are concerned. It appears that selectivity of the extraction method leaves much to be desired.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00000069
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  • 38
    Digitale Medien
    Digitale Medien
    Deepwater sediments and trophic conditions in Florida lakes (1982)
    Springer
    Hydrobiologia 91-92 (1982), S. 597-602 
    Details
    ISSN: 1573-5117
    Schlagwort(e): eutrophication ; diagenesis ; sediments ; nitrogen
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Sediment cores were taken from near maximum depth in 15 Florida lakes representing a wide range of trophic conditions. Chemical analyses of surface sediments showed Al, Fe, and Ca to be the most abundant elements in all samples, and the ratio of Al to Ca to be smaller for eutrophic lakes. Sediment organic matter increased with trophic state, as did the degree to which it was enriched in nitrogen. Corresponding sediment C/N ratios decreased with increasing lake trophic state and showed significant negative correlation with chlorophylla, total N, and total P in the water column. Concentrations of sedimentary chlorophyll derivatives showed some relation to trophic state but differences in basin morphometry hinder its use as an inter-lake index of chlorophyll production.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00940148
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  • 39
    Digitale Medien
    Digitale Medien
    Introduction (1982)
    Springer
    Hydrobiologia 91-92 (1982), S. 1-8 
    Details
    ISSN: 1573-5117
    Schlagwort(e): symposium ; sediments ; freshwater
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02391917
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  • 40
    Digitale Medien
    Digitale Medien
    Comparison of sediment energy-texture relationships in marine and lacustrine environments (1982)
    Springer
    Hydrobiologia 91-92 (1982), S. 71-84 
    Details
    ISSN: 1573-5117
    Schlagwort(e): sediments ; lakes ; seas ; oceans ; energy relationships ; population statistics
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Sediments in the marine environment are generally subject to higher energy levels than those of lake systems, and lakes are virtually unaffected by tidal range which modifies beach structures formed in response to wave effects. However, despite different energy levels, the textural characteristics of both marine and lacustrine sediments are very similar. The main difference between marine and lacustrine facies is the depth range over which these characteristics remain consistent. In lakes, depth limitation may influence the development of surface waves and restrict textural distributions. Simple textural relationships can be used to describe comparable marine and lacustrine sedimentary conditions. Sediments which have been altered by post-depositional erosion, such as lag deposits, or by ice-drop or wind blown settlement, show comparable textural modifications. The settlement of silt and clay size particulates, in the marine environment and lakes, may differ slightly because of the chemical differences between salt and fresh water.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02391923
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  • 41
    Digitale Medien
    Digitale Medien
    Whole-lake lead burdens in sediments of lakes in southern Ontario, Canada (1982)
    Springer
    Hydrobiologia 91-92 (1982), S. 121-130 
    Details
    ISSN: 1573-5117
    Schlagwort(e): sediments ; lead
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The anthropogenic stable lead content of the sediments of eight softwater Precambrian lakes in southern Ontario was measured at 34–92 sites per lake. Whole-lake anthropogenic lead burdens varied between only 610 and 770 mg m−2. There was no relationship between lead burden and either water replenishment time of the lake (TW) or the ratio of watershed area to lake area (Ad/A0), which varied by factors of 4 and 12 respectively. These results can be explained if a) the lead deposition in this region is uniform, and b) the only significant input of lead to the lakes is via deposition from the atmosphere directly on the lakes' surfaces. Therefore spatial differences in anthropogenic lead within a lake represent the redistribution or focusing pattern of the sediments.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02391927
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  • 42
    Digitale Medien
    Digitale Medien
    Particle size distribution and chemical parameters of the sediments of a shallow turbid impoundment (1982)
    Springer
    Hydrobiologia 91-92 (1982), S. 341-353 
    Details
    ISSN: 1573-5117
    Schlagwort(e): Impoundment ; sediments ; particle size ; major ions ; nutrients ; cation exchange
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract As part of an ecosystem study of a small mesotrophic turbid impoundment in the semi-arid part of South Africa, an investigation was made of the particle size distribution, organic content and inorganic chemical composition of the sediment. Nine transects 50 m apart were made during February 1980. Sediments were sampled with an Eckman grab. The following analyses were made: size fractionation by wet sieving, cation exchange capacity, exchangeable Na, K, Ca, Mg and PO4, total P, and loss on ignition. From the results it was clear that the finer particles, in or near the original river bed, had higher cation exchange capacity, total P, exchangeable phosphorus and organic content. Littoral areas with avian habitat and extensive macrophyte vegetation, contained coarser sediments. Organic detritus apparently migrated to the deeper part of the impoundment. Sediments of lacustrine and fluvial origin were identified by means of the Passega classification.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02391950
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  • 43
    Digitale Medien
    Digitale Medien
    Lake sediments as recorders of geomagnetic field variations — applications to dating post-Glacial sediments (1982)
    Springer
    Hydrobiologia 91-92 (1982), S. 587-596 
    Details
    ISSN: 1573-5117
    Schlagwort(e): dating ; sediments ; geomagnetic variations
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Field and laboratory methods, developed to recover the record of past secular variations of geomagnetic declination and inclination carried by the remanent magnetization of some lake sediments, are described. Type curves, delineating these parameters through post-Glacial time, have now been constructed for Europe and east-central N. America. These curves, once established for any region, are useful for dating lake sediments from that region. The principal inclination features exhibited by the European curves can also be identified along the N. American curves with a delay of some 600 years, on average.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00000057
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  • 44
    Digitale Medien
    Digitale Medien
    Stratigraphic and dynamic effects of sediment reworking by Great Lakes zoobenthos (1982)
    Springer
    Hydrobiologia 91-92 (1982), S. 611-622 
    Details
    ISSN: 1573-5117
    Schlagwort(e): zoobenthos ; Great Lakes ; sediments ; radionuclides
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Recent sediments of the North American Great Lakes are inhabited by numerous species of macrobenthos which alter the physical and chemical properties of sediments and modify interface transport characteristics. Distributions of such radionuclides as cesium-137, lead-210, and isotopes of plutonium exhibit a zone of constant activity extending down from the sediment-water interface from 1 to 15 cm. Recent studies have confirmed that radiometrically determined mixed depths are consistent with the vertical distribution of oligochaete worms and the amphipod, Pontoporeia hoyi. Generally, 90% of the benthos are contained within the radiometrically defined mixed zone. Where comparisons are possible, rates of sediment reworking by ‘conveyor belt’ species are comparable to or exceed sedimentation rates. Systematic variations in the mixed depth occur within depositional basins with greatest depths tending to be associated with least consolidated, organically rich materials. A quantitative steady-state mixing model accounts satisfactorily for observed radioactivity and heavy metal profiles. Bioturbation appears to be an important process, limiting the resolution with which historical records of particle-associated contaminants may be reconstructed from sediment cores. As bioturbation serves to maintain contact of contaminated sediments with overlying water, this time may also characterize the long-term lake recovery for contaminants removed by burial. As the time varies with location, a mean for an entire lake is not well known, but is on the order of 20 years for Lake Huron.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00000060
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  • 45
    Digitale Medien
    Digitale Medien
    Standardization of methods of analysis for heavy metals in sediments (1982)
    Springer
    Hydrobiologia 91-92 (1982), S. 689-695 
    Details
    ISSN: 1573-5117
    Schlagwort(e): standardization ; heavy metals ; sediments ; base-line levels ; chemical partition
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract In studies of heavy metals in sediments, there is a need for standardization of the procedures for sample collection and preservation, chemical analyses and presentation of results. The method and depth of sampling depend on the aim of the investigation and on local sediment conditions, such as consistency of the sediment, rate of sedimentation, diagnetic processes and bioturbation. Therefore no general recommendations can be given in this respect. During collection and preservation, contamination and loss of constituents ust be avoided. In sediments, the best means for estimating total contents of metals is digestion with HF, in combination with strong acids. Other methods include X-ray fluorescence and neutron activation analyses. The use of HF is considered objectionable by some laboratories. A reasonable alternative is aqua regia. Because variations in granular composition affect metal contents, it is advisable to use the fraction 〈 63 μm for the analysis. Chemical partition of sediments provides an insight into the source of metallic constituents, and their pathways to deposition areas. A three-step extraction procedure, in the sequence 0.1 M hydroxylamine-HCl, H2O2 30% and HF, is proposed. Finally, attention is paid to the anthropogenic enrichment of metals in sediments. The establishment of base-line levels is discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00000068
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  • 46
    Digitale Medien
    Digitale Medien
    Whole-lake lead burdens in sediments of lakes in southern Ontario, Canada (1982)
    Springer
    Hydrobiologia 91-92 (1982), S. 121-130 
    Details
    ISSN: 1573-5117
    Schlagwort(e): sediments ; lead
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The anthropogenic stable lead content of the sediments of eight softwater Precambrian lakes in southern Ontario was measured at 34–92 sites per lake. Whole-lake anthropogenic lead burdens varied between only 610 and 770 mg m−2. There was no relationship between lead burden and either water replenishment time of the lake (TW) or the ratio of watershed area to lake area (Ad/A0), which varied by factors of 4 and 12 respectively. These results can be explained if a) the lead deposition in this region is uniform, and b) the only significant input of lead to the lakes is via deposition from the atmosphere directly on the lakes' surfaces. Therefore spatial differences in anthropogenic lead within a lake represent the redistribution or focusing pattern of the sediments.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00940101
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  • 47
    Digitale Medien
    Digitale Medien
    Zinc in water and sediments of two finnish lakes (1982)
    Springer
    Hydrobiologia 91-92 (1982), S. 155-160 
    Details
    ISSN: 1573-5117
    Schlagwort(e): heavy metals ; zinc ; lakes ; sediments ; pollution ; industrial load ; sedimentation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The distribution of zinc in Lake Vanajavesi and Lake Mallasvesi, South Finland, was determined on the basis of water and sediment studies. Lake Vanajavesi is one of the most polluted of large inland lakes, in Finland. The zinc load comes mainly from industrial sources. Lake Mallasvesi, situated near Vanajavesi, is in almost natural condition. The water samples were taken by a Ruttner sampler. In collecting sediment samples, a freezing technique was used. The results of zinc analyses indicate that, during several winters, zinc has spread with waste water to different parts of L. Vanaja against the main course of flow. A close correlation between sedimentation of zinc and waste discharge from a textile factory was found in the present study.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00940105
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  • 48
    Digitale Medien
    Digitale Medien
    Model for instream regulation of radioisotopes and heavy metals in riverine waters subjected to a uranium mill discharge (1982)
    Springer
    Hydrobiologia 91-92 (1982), S. 175-188 
    Details
    ISSN: 1573-5117
    Schlagwort(e): simulation ; sediments ; radioisotopes ; heavy metals
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract In the Athabaska sandstone region of northern Saskatchewan, mining and milling of uranium-bearing ore is subjecting, and will continue to subject, surface waters to inputs of soluble heavy metals and uranium and thorium decay series radioisotopes. A mathematical simulation model was developed to assess the role of riverine sediments in regulating soluble concentrations of heavy metals and radioisotopes released to the environment through treated mining and milling process effluents. Specific elements studied included As, Ni, Pb, U, and Ra-226. The model considered that diffusion into sediment porewater and adsorption by sediment particulates from sediment porewater were the two dominant mechanisms regulating sediment loading. Experiments indicated that the equilibrium adsorption behaviour of the heavy metals and radioisotopes studied could be adequately explained using a linear adsorption isotherm, over the range of concentrations expected in the environment. Experimentally determined linear isotherm slopes ranged from 200 ml g−1 to 21 000 ml gl. Diffusion into the effective depth of the sediments (20 cm) was modelled using a quadratic (second order) driving force and a corresponding mass transfer coefficient. The model coefficients were calibrated using field and laboratory data. Results of the modelling suggested that the sediments have a small effect on instream concentrations during the active phases of mining and milling. The sediments were predicted to accumulate sufficient adsorbed mass, during the operational phase of mining and milling, to act as a distributed instream source after completion of milling activities. The significance of this post-operational source was a function of the initial effluent loading, elapsed time and site specific river characteristics.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02391934
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  • 49
    Digitale Medien
    Digitale Medien
    Transport of iron and manganese in relation to the shapes of their concentration-depth profiles (1982)
    Springer
    Hydrobiologia 91-92 (1982), S. 463-471 
    Details
    ISSN: 1573-5117
    Schlagwort(e): iron ; manganese ; sediments ; water ; transport ; model
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract A model is presented which describes the transport of iron and manganese in the vicinity of a redox boundary. It is based on input of a particulate component, to form a point source, from which soluble species diffuse along a concentration gradient. The shapes of concentration-depth profiles in marine and freshwater sediments and water columns are reviewed and discussed in terms of the model. Transport, either entirely within a water column or within the sediment, may be simply treated because the rate of vertical transport can be regarded as constant. The discontinuity in the rate of vertical transport which occurs at the sediment-water interface can provide a complicated example of the model, especially when it coincides with the redox boundary. Authigenic mineral formation processes can modify the model, sometimes to such an extent that it becomes invalid. This is particularly true for soluble iron profiles in organically rich marine sediments. Sampling interval is critical to the resultant profile shape and must be relevant to the particular environment, e.g. metres in water columns and millimetres in sediments. The differences in the rates of reduction and oxidation of iron and manganese tend to modify both the position of the profile with respect to the redox-cline and its stage of development in a seasonally anoxic system. It is these factors which determine why most of the iron which reaches a sediment is permanently incorporated whereas manganese is re-released. This mechanism determines the average ratio of iron to manganese in sedimentary rocks. The development of peaked profile shapes in water columns implies that under certain conditions dissolved iron and manganese may be transported from the water column to the pore waters of the sediment.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00940134
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  • 50
    Digitale Medien
    Digitale Medien
    Lake sediments as recorders of geomagnetic field variations — applications to dating post-Glacial sediments (1982)
    Springer
    Hydrobiologia 91-92 (1982), S. 587-596 
    Details
    ISSN: 1573-5117
    Schlagwort(e): dating ; sediments ; geomagnetic variations
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Field and laboratory methods, developed to recover the record of past secular variations of geomagnetic declination and inclination carried by the remanent magnetization of some lake sediments, are described. Type curves, delineating these parameters through post-Glacial time, have now been constructed for Europe and east-central N. America. These curves, once established for any region, are useful for dating lake sediments from that region. The principal inclination features exhibited by the European curves can also be identified along the N. American curves with a delay of some 600 years, on average.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00940147
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  • 51
    Digitale Medien
    Digitale Medien
    Stratigraphic and dynamic effects of sediment reworking by Great Lakes zoobenthos (1982)
    Springer
    Hydrobiologia 91-92 (1982), S. 611-622 
    Details
    ISSN: 1573-5117
    Schlagwort(e): zoobenthos ; Great Lakes ; sediments ; radionuclides
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Recent sediments of the North American Great Lakes are inhabited by numerous species of macrobenthos which alter the physical and chemical properties of sediments and modify interface transport characteristics. Distributions of such radionuclides as cesium-137, lead-210, and isotopes of plutonium exhibit a zone of constant activity extending down from the sediment-water interface from 1 to 15 cm. Recent studies have confirmed that radiometrically determined mixed depths are consistent with the vertical distribution of oligochaete worms and the amphipod,Pontoporeia hoyi. Generally, 90% of the benthos are contained within the radiometrically defined mixed zone. Where comparisons are possible, rates of sediment reworking by ‘conveyor belt’ species are comparable to or exceed sedimentation rates. Systematic variations in the mixed depth occur within depositional basins with greatest depths tending to be associated with least consolidated, organically rich materials. A quantitative steady-state mixing model accounts satisfactorily for observed radioactivity and heavy metal profiles. Bioturbation appears to be an important process, limiting the resolution with which historical records of particle-associated contaminants may be reconstructed from sediment cores. As bioturbation serves to maintain contact of contaminated sediments with overlying water, this time may also characterize the long-term lake recovery for contaminants removed by burial. As the time varies with location, a mean for an entire lake is not well known, but is on the order of 20 years for Lake Huron.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00940150
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  • 52
    Digitale Medien
    Digitale Medien
    Gas chromatographic determination of total amino acids and protein in sediments using the ninhydrin-CO2 reaction (1982)
    Springer
    Hydrobiologia 97 (1982), S. 81-86 
    Details
    ISSN: 1573-5117
    Schlagwort(e): amino acids ; protein ; sediments ; ninhydrin reaction ; gas chromatography
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract A sensitive modification of the ninhydrin-CO2 method involving the gas chromatographic determination of the total protein and amino acid content of sediment is described. The method gives a linear response over the amino acid concentration range 10−5 M to 4 × 10−2 M. It can be used for whole sediment, hydrolysates and interstitial water. The performance of the method is compared with the fluorescamine method for primary amines.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00014961
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  • 53
    Digitale Medien
    Digitale Medien
    The obstruction factor γ in gas chromatography (1981)
    Springer
    Chromatographia 14 (1981), S. 576-578 
    Details
    ISSN: 1612-1112
    Schlagwort(e): Gas chromatography ; Tortuosity factor
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Summary The relationship between the obstructive factor γ and velocity was restudied. The dependence of the obstructive factor on velocity was verified. The effects of diffusion coefficient and particle-to-column diameter ratio on the obstructive factor-velocity relationship were investigated. The results are consistent with Hawkes' hypothesis that values of γ at low velocities are averages over tightly packed and loosely packed domains while at high velocities they are weighted in favour of the loosely packed domains where there is more flow.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02262886
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  • 54
    Digitale Medien
    Digitale Medien
    Blending bulk dissolution and gas-liquid-adsorption with the mixing of two liquid stationary phases to increase selectivity (1981)
    Springer
    Chromatographia 14 (1981), S. 648-652 
    Details
    ISSN: 1612-1112
    Schlagwort(e): Gas chromatography ; Gas-liquid adsorption ; Bulk solution ; Mixed stationary phases
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Summary It is shown that the blending of some retention effects can make the resolution of complex mixtures on short classical columns as effective as on capillary columns.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02291105
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  • 55
    Digitale Medien
    Digitale Medien
    Headspace gas chromatographic determination of aromatic hydrocarbons in natural and waste water (1981)
    Springer
    Chromatographia 14 (1981), S. 699-703 
    Details
    ISSN: 1612-1112
    Schlagwort(e): Gas chromatography ; Headspace analysis ; Aromatic hydrocarbons ; Water analyses
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Summary The possibilities of using headspace analysis of aromatic hydrocarbon traces in aqueous solutions with changing values of the partition coefficients are discussed. A variant of headspace analysis of the simplest aromatic hydrocarbon in natural and waste water is described. It involves two-step gaseous extraction of a sample in vessels of varying volume before and after the equilibrium phase is replaced with a pure gas (air or nitrogen). This method permits to analyse 5–50 ml water samples with benzene and toluene contents varying from the ppb to the ppm range within an error not exceeding 155. The analysis time is about 1.5 h. The presence of non-volatile organic or mineral substances does not influence the determination. This method is unsuitable to heterogeneous systems (aqueous oil emulsions): before carrying out the analysis for the hydrocarbon content these systems have to be homogenized first.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02259458
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  • 56
    Digitale Medien
    Digitale Medien
    Factors affecting reproducibility in the manufacture of glass and siliceous glass open tubular (capillary) columns (1981)
    Springer
    Chromatographia 14 (1981), S. 484-487 
    Details
    ISSN: 1612-1112
    Schlagwort(e): Gas chromatography ; Open tubular (capillary) columns ; Glass columns ; Fused-silica columns ; Column testing
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Summary Column characteristics affecting the chromatographic behavior of glass and siliceous glass (“fused silica”) capillary columns include the dimensional uniformity of the column, the physical and chemical characteristics of the column wall and the characteristics of the liquid phase. In the case of the coated column the uniformity and thickness of the liquid phase film are the most important criteria affecting column reproducibility. The paper discusses these factors and their influence on column performance.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02263539
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  • 57
    Digitale Medien
    Digitale Medien
    Analysis of complex industrial samples by gas chromatography; a report on selected past activities (1981)
    Springer
    Chromatographia 14 (1981), S. 203-211 
    Details
    ISSN: 1612-1112
    Schlagwort(e): Gas chromatography ; Quantitative analysis ; Copper oxide converter ; Inorganic gas analysis ; Determination of fluorine and oxygen ; Hydrocarbon analysis ; Wine analysis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Summary A review of past activities concerning selected industrial analytical problems is given. This includes the following question: preparation of pure gas mixtures to be used for calibration, catalytic conversion of ester and pyridin samples to carbon dioxide and a one-point calibration method using peak heights, both for quantitative analysis, analysis of gas mixtures containing fluorine and inorganic fluorine compounds and the determination of the oxygen and fluorine content of the sample, separation and identification of hydrocarbons in shale oil and petroleum fraction samples, and analysis of wine.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02260153
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  • 58
    Digitale Medien
    Digitale Medien
    Analysis of trimethylsilyl-isopropylidene derivatives of sorbose by combined gas chromatography- and mass-spectrometry (1982)
    Springer
    Chromatographia 15 (1982), S. 704-706 
    Details
    ISSN: 1612-1112
    Schlagwort(e): Gas chromatography ; Isopropyliden-sorboses ; TMS-derivatives ; GC-MS combined technique ; Mass spectra
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Summary A method has been developed using gas chromatography — electron impact mass spectrometry for the determination of the di-0-isopropylidene-sorbofuranose and mono-0-isopropylidene-sorbofuranose. The compounds are separated as their trimethylsilyl derivatives on a capillary column coated with the stationary phase SE-52. The mass spectra show that the silylation reaction is quantitiative and that the isopropylidene groups does not change.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02261889
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  • 59
    Digitale Medien
    Digitale Medien
    Gas chromatographic analysis of ethylbenzene hydroperoxide (1982)
    Springer
    Chromatographia 15 (1982), S. 183-185 
    Details
    ISSN: 1612-1112
    Schlagwort(e): Gas chromatography ; Analysis of ethylbenzene hydroperoxide ; Time normalization method
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Summary A gas chromatographic method, based on the time normalization technique, is described for the analysis of ethylbenzene hydroperoxide in mixtures containing ethylbenzene, acetophenone, 1-phenylethanol, benzaldehyde and phenol. Different liquid phases were tested and the best results were obtained with tricresyl phosphate and neopentyl glycol sebacate. The influence of the support, the liquid loading and the gas velocity are discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02261537
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  • 60
    Digitale Medien
    Digitale Medien
    Retention index values of hydrocarbons on open-tubular columns coated with methylsilicone liquid phases (1982)
    Springer
    Chromatographia 15 (1982), S. 625-630 
    Details
    ISSN: 1612-1112
    Schlagwort(e): Gas chromatography ; Open-tubular (capillary) columns ; Comparison of liquid phases ; Influence of temperature ; Retention index data
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Summary The influence of temperature and liquid phase film thickness of open-tubular (capillary) columns on the retention index values of hydrocarbons on methylsilicone liquid phases is discussed. Data obtained on methylsilicones and squalane are compared. Retention index values of 43 hydrocarbons between 40 and 70 °C on OV-101 liquid phase are listed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02279488
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  • 61
    Digitale Medien
    Digitale Medien
    Kinetic study of the drying step of supported catalysts by reversed-flow gas chromatography (1982)
    Springer
    Chromatographia 15 (1982), S. 351-354 
    Details
    ISSN: 1612-1112
    Schlagwort(e): Supported catalysts ; Reserved-flow GC ; Drying step ; Gas chromatography
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Summary Application of reversed-flow gas chromatography to study the drying step in the preparation of supported catalysts is proposed. It is demonstrated that this technique can be applied to investigate the kinetic law followed, as well as to obtain kinetic parameters of drying (rate constants, activation energies and frequency factors). Amaterial illustrating this application is γ-Al2O3 impregnated with usual organic solvents (n-C5H12,n-C6H14,n-C7H16, CH3COCH3 and CH3CH2OH). It was found that in all cases above a simple first-order law based onone kind of active site is followed. Moreover, it was observed that the activation energyE a of the drying process increases almost linearly with the relative molecular mass of the solvent, whereas for the same solventE a increases with the amount used. The operation of a kinetic compensation effect suggests “similar” activated complexes of the various solvents used.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02259216
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  • 62
    Digitale Medien
    Digitale Medien
    Characterization, evaluation and in-situ cross-linking of new polar phases in capillary gas chromatography (1982)
    Springer
    Chromatographia 16 (1982), S. 63-68 
    Details
    ISSN: 1612-1112
    Schlagwort(e): Gas chromatography ; Fused silica capillaries ; New polar phases: OV-1701 and RSL-310 ; Immobilization
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Summary The possibilities of OV-1701 and RSL-310, two new stationary phases, have been evaluated for capillary gas chromatography in fused silica columns. OV-1701 is a cyanopropylphenyldimethyl polysiloxane of moderate polarity possessing excellent chromatographic characteristics. The phase exhibits high coating and chromatographic efficiencies, high temperature stability and is suitable for cross-linking. RSL-310 is a polar liquid stationary phase yet to be permanently bonded in a capillary column. The selectivity of both phases extends the applicability of fused silica columns.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02258871
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  • 63
    Digitale Medien
    Digitale Medien
    Capillary gas chromatography of esters correlations between structure and retention index (1981)
    Springer
    Chromatographia 14 (1981), S. 143-147 
    Details
    ISSN: 1612-1112
    Schlagwort(e): Capillary columns ; Gas chromatography ; Retention index ; Structure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Summary The retention index of twenty different homologous series of esters have been determined experimentally on polar (Carbowax 1540) and non-polar (squalane) columns. General equations to calculate retention index have been established by statistical methods. The influence of the length and inductive effect of acid and alcohol chains and the relative position of the carboxylic group are discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02314758
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  • 64
    Digitale Medien
    Digitale Medien
    Kaolin as support for porous layer open tubular columns (1981)
    Springer
    Chromatographia 14 (1981), S. 285-288 
    Details
    ISSN: 1612-1112
    Schlagwort(e): Gas chromatography ; Porous layer open tubular columns ; Kaolin as support ; Column performance
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Summary PLOT columns have been prepared with kaolin as the liquid phase support. These columns show good efficiency with different stationary phases and good thermal stability with polar phases. The performance of columns is shown by the separation of various mixtures such as fatty acids, phenols and anilines which are of analytical importance.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02259267
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  • 65
    Digitale Medien
    Digitale Medien
    Separation of xylidine isomers on heteroaromatic compounds by gas-liquid chromatography (1981)
    Springer
    Chromatographia 14 (1981), S. 39-40 
    Details
    ISSN: 1612-1112
    Schlagwort(e): Xylidine isomers ; Heteroaromatic liquid phases ; Gas chromatography
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Summary Nicotinic acid and 1H-benzotriazole appreciably resolved all the xylidine (dimethylaniline) isomers, while benzimidazole, nicotinamide and phthalimide can also separate all the isomers except 2,4- and 2,3-xylidines. The analyses were carried out on supports which were not treated with an alkali.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02262060
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  • 66
    Digitale Medien
    Digitale Medien
    Mixed phases of Superox 20M and OV-1 in fused silica and glass capillary gas chromatography (1981)
    Springer
    Chromatographia 14 (1981), S. 345-350 
    Details
    ISSN: 1612-1112
    Schlagwort(e): Gas chromatography ; Silica capillaries ; Glass capillaries ; Mixed gum phases ; Polarity and selectivity
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Summary Mixed phases of Superox 20M and OV-1 can be coated homogeneously on the untreated wall of fused silica capillary columns. Excellent columns with regard to efficiency, inertness and thermal stability can be obtained. (CE〉95% and MAOT≥250°). The polarity and selectivity were ascertained with Rohrschneider-Reynolds probes and a capillary polarity test mixture. The analysis of an essential oil mixture illustrates the possibilities of mixed phases in practical capillary GC.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02259233
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  • 67
    Digitale Medien
    Digitale Medien
    Gas-liquid chromatography of isopropylidene monosaccharides and their trimethylsilyl derivatives (1982)
    Springer
    Chromatographia 15 (1982), S. 241-244 
    Details
    ISSN: 1612-1112
    Schlagwort(e): Gas chromatography ; Monosaccharides ; Polyols ; GC of TMS derivatives
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Summary This paper describes the gas chromatographic separation of the mixture of isopropylidene monosaccharides, and their trimethylsilyl derivatives. Based on the total analysis time and resolution the best stationary phase was SF-96 using Chromosorb G as the solid support and temperature programming.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02265655
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  • 68
    Digitale Medien
    Digitale Medien
    A new device for contamination-free injection for gas chromatographic trace estimation of oxygen and nitrogen (1982)
    Springer
    Chromatographia 15 (1982), S. 312-314 
    Details
    ISSN: 1612-1112
    Schlagwort(e): Gas chromatography ; Injection-port modification ; Oxygen and nitrogen traces
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Summary The paper presents a new device modifying normal injection port of a gas chromatograph for eliminating air contamination thus enabling determination of traces of oxygen or nitrogen. Further modification is also proposed which enables the analysis to be carried out with a limited quantity of sample gas. Potential application of this device in the analysis of reactive gases like florine has been indicated.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02265684
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  • 69
    Digitale Medien
    Digitale Medien
    Occurrence and prevention of isomerization of ligustilide during gas-liquid chromatography on packed columns (1982)
    Springer
    Chromatographia 15 (1982), S. 358-360 
    Details
    ISSN: 1612-1112
    Schlagwort(e): Phthalides ; Gas chromatography ; Chromosorb W ; Isomerization ; Ligustilide
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Summary During GLC of naturally occurring mixtures of phthalides on packed columns an artefact was sometimes detected that originated from Z-ligustilide. Active sites of Chromosorb W were responsible for the formation of the artefact, that was assumed to be E-ligustilide as GC-MS revealed that its mass spectrum was identical with that of Z-ligustilide. No isomerization was observed when freshly coated Chromosorb W was used or the support was deactivated by benzoyl chloride or melamine. The identity of the artefact was confirmed by UV irradiation experiments.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02259218
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  • 70
    Digitale Medien
    Digitale Medien
    Characterization of glass, quartz, and fused silica capillary column surfaces from contact-angle measurements (1981)
    Springer
    Chromatographia 14 (1981), S. 387-397 
    Details
    ISSN: 1612-1112
    Schlagwort(e): Gas chromatography ; Capillary columns ; Fused silica ; Contact angle ; Wettability
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Summary This paper describes the systematic characterization of glass and the newly introduced fused silica and quartz capillary columns from surface wettability measurements. Common gas chromatographic stationary phases were used in capillary-rise measurements at temperatures up to 300°C. By construction of Zisman plots and using the Cassie equation, the relative surface concentrations of wettable and non-wettable groups were determined. By application of the Fowkes equation, the dispersion force component of the surface energy was investigated. The influence of various surface treatments such as leaching, silylation, and polymeric film formation are discussed. Wettability measurements were also used to evaluate the thermostability of various treated surfaces and to compare the surface properties of glass, quartz, and fused silica. The wettability of the surfaces with selected stationary phases as a function of temperature is also discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02262872
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  • 71
    Digitale Medien
    Digitale Medien
    Determination of average molecular polarizabilities of polycyclic aromatic hydrocarbons directly from retention indices (1981)
    Springer
    Chromatographia 14 (1981), S. 707-708 
    Details
    ISSN: 1612-1112
    Schlagwort(e): Gas chromatography ; Polycyclic aromatic hydrocarbons ; Retention index ; Average molecular polarizabilities
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Summary A significant correlation has been found between the retention indices of polycyclic aromatic hydrocarbons on non-polar stationary phases and the average molecular polarizabilities of the molecules separated on these phases. Equations have been derived for the determination of the average molecular polarizabilities, directly from the retention indices.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02259460
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  • 72
    Digitale Medien
    Digitale Medien
    Factors affecting the retention of polycyclic aromatic hydrocarbons in gas chromatography (1981)
    Springer
    Chromatographia 14 (1981), S. 69-72 
    Details
    ISSN: 1612-1112
    Schlagwort(e): Gas chromatography ; Polynuclear aromatic hydrocarbons ; Retention index ; Vapour pressure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Summary The retention index of a planar polynuclear aromatic hydrocarbon on the GC phases OV-101, SE-52, and OV-17 is strictly related only to the boiling point, and less closely to the relative molecular mass. The very approximates relation with connectivity index ins only a consequence of the latter. On a nematic lqiuid crystal phase, a variation of activity coefficient, expressed in terms of a shape factor, also influences the retention of PAH.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02279514
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  • 73
    Digitale Medien
    Digitale Medien
    Analysis of trace components in gases by gas chromatography (1981)
    Springer
    Chromatographia 14 (1981), S. 269-276 
    Details
    ISSN: 1612-1112
    Schlagwort(e): Gas chromatography ; Detector performance ; Trace analysis ; Catalytic conversion ; Multidimensional gas chromatography
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Summary Relationships are derived describing how the detection limit of a chromatographic system depends on the minimum detectable limit of the detector and the chromatographic parameters such as column length, efficiency, carrier gas flow rate and the capacity factor. Performance data of detectors developed in the last 25 years at the Dalian Institute of Chemical Physics of the Chinese Academy of Sciences are given and a few selected application examples are listed. These include trace analysis by preconcentration and by direct analysis and the utilization of multidimensional gas chromatography with two columns, two detectors, a 12-port valve, and a catalytic conversion reactor.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02259264
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  • 74
    Digitale Medien
    Digitale Medien
    A column packing for isothermal gas chromatographic analysis of C1−C5 paraffins and monoolefins and dimethyl ether (1981)
    Springer
    Chromatographia 14 (1981), S. 277-278 
    Details
    ISSN: 1612-1112
    Schlagwort(e): Gas chromatography ; C1−C5 Hydrocarbons ; Dimethyl ether
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Summary An analytical GC method was developed which uses a single packed column consisting of three packings in series prepared with the following liquid phases: dimethyl sulfolane, propylene carbonate, and silver nitrate. This system provides satisfactory resolution of mixtures of C1−C5 hydrocarbons and dimethyl ether obtained when converting methanol to gasoline. Due to the high capacity of the column it is possible to inject larger sample amounts permitting trace analysis.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02259265
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  • 75
    Digitale Medien
    Digitale Medien
    Analysis of phthalides from umbelliferae by combined liquid-solid and gas-liquid chromatography (1981)
    Springer
    Chromatographia 14 (1981), S. 452-454 
    Details
    ISSN: 1612-1112
    Schlagwort(e): Phthalides ; Umbelliferae ; Liquid-solid chromatography ; Gas chromatography ; Ligustilide
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Summary A liquid-solid chromatographic pre-fractionation of naturally occurring phthalides has been developed. The LSC was carried out on a column of silica applying a 1–50% gradient elution of diethyl ether (containing 2% methanol) in pentane. The enrichment in the fractions led to better possibilities for a gas chromatographic separation and isolation allowing further studies by spectroscopic methods. Ligustilide may easily isomerize during GC as a result of ageing of the column.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02263532
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  • 76
    Digitale Medien
    Digitale Medien
    Gas chromatographic determination of arsenic in low concentrations in inorganic materials (1982)
    Springer
    Chromatographia 15 (1982), S. 30-32 
    Details
    ISSN: 1612-1112
    Schlagwort(e): Gas chromatography ; Arsenic ; Inorganic materials
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Summary A method is described for the quantitative chlorination and extraction of arsenic as arsenic trichloride from a number of alloys. The conditions for the quantitative gas chromatographic measurement of the volatile chloride have been studied. The proposed method for inorganic materials is very fast giving results within 10 min; sensitive, 1.5·10−13 g As can be detected, simple and accurate. At the ng level of As the error is about 20% with a standard deviation less than 20%, and at the 10pg level the error is about 36% with a standard deviation of 44%.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02269036
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  • 77
    Digitale Medien
    Digitale Medien
    Multiple preparative chromatography (1982)
    Springer
    Chromatographia 15 (1982), S. 765-768 
    Details
    ISSN: 1612-1112
    Schlagwort(e): Gas chromatography ; Preparative scale chromatography ; Capacity ; Dual-stage separation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Summary The capacity of different versions of single- and dual-stage separation of mixtures on a preparative scale is considered. It has been shown that dual-stage separation with intermediate condensation considerably enhances the capacity of the installation as compared with a single-stage process.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02261373
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  • 78
    Digitale Medien
    Digitale Medien
    High efficiency microbore GC columns using porous bead supports (1982)
    Springer
    Chromatographia 15 (1982), S. 117-124 
    Details
    ISSN: 1612-1112
    Schlagwort(e): Various packed GC column ; Gas chromatography ; Porous layer beads ; GC/MS analysis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Summary Theoretical comparisons of various packed GC column types are presented with respect to analysis time, efficiency, sample dilution, and sample capacity for a given maximum inlet pressure. In particular, totally porous particles, porous layer beads, and glass beads are compared with one another. It is shown that 30 μm porous layer beads offer a useful compromise between analysis time and plate count with relatively good sample capacity. Moreover, when using 1 mm i.d. columns (microbore), outlet flow rates that are reasonable for direct coupling to magnetic sector mass spectrometers are achieved making these columns suitable for GC/MS. Using 30 μm Zipax porous layer beads, columns yielding 8,000 to 10,000 plates/meter have been produced with inlet pressures of 13 to 26 atm. A simple modification of the injection port converts the maximum inlet pressure of a commercial gas chromatograph to 26 atm. With such pressures, columns in excess of 20,000 plates can be achieved. Chromatograms are presented illustrating the promise of these microbore columns for GC and GC/MS analysis.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02290444
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  • 79
    Digitale Medien
    Digitale Medien
    A chromatoscopic study of fluorene, indenes and styrene (1982)
    Springer
    Chromatographia 15 (1982), S. 245-248 
    Details
    ISSN: 1612-1112
    Schlagwort(e): Chromatoscopy ; Gas chromatography ; Graphitized carbon black ; Molecular structure and retention ; Aromatic hydrocarbons
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Summary A molecular-statistical calculation of the retention volumes at zero sample size on graphitized thermal carbon black is carried out for quasi-rigid molecules of fluorene, indene, 1-methylindene, 2-methylindene and three dimethylindenes. A reasonable agreement is observed between the calculated and the available experimental gas chromatographic data. The potential barrier to internal rotation and the torsional angle in styrene molecules are estimated by comparing theoretically calculated and measured retention volumes.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02265656
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  • 80
    Digitale Medien
    Digitale Medien
    Gas chromatography in qualitative analyses. An investigation of the oxidation of some silicones used as gas chromatographic stationary phases (1982)
    Springer
    Chromatographia 15 (1982), S. 355-357 
    Details
    ISSN: 1612-1112
    Schlagwort(e): Gas chromatography ; Silicone liquid phases ; Oxidation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Summary The on-column oxidation of apolar and polar silicones used as gas chromatographic stationary phases is investigated. Even at 225° the effects of oxidation are found to be slight. Of the materials investigated the methylphenylsilicones are the most stable.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02259217
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  • 81
    Digitale Medien
    Digitale Medien
    Glass capillary gas chromatography of chlorinated methyl acetates, propanoates and butanoates on Carbowax 20M and SE-30 columns (1982)
    Springer
    Chromatographia 15 (1982), S. 505-508 
    Details
    ISSN: 1612-1112
    Schlagwort(e): Glass capillary ; Gas chromatography ; Methyl chloroacetates ; Methyl chloropropanoates ; Methyl chlorobutanoates
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Summary The gas chromatography of all chlorinated methyl acetates, methyl propanoates and methyl mono- and dichlorobutanoates has been studied on Carbowax 20M and SE-30 glass capillary columns under various running conditions. The order of elution on a non-polar column was largely determined by the boiling point of esters, whereas on a polar column it was much influenced by the structure of compounds. Complete separation of the combined mixture of all 27 compounds could not be achieved, however, methyl 3,3-dichlorobutanoate was the only ester overlapped on both columns in spite of the various column temperatures used. The best separation of the mixture was on Carbowax 20M with a temperature program from 50°C at 8°C/min, isothermal running conditions leading either to poor separation of volatile components or long analysis time and broad peaks of higher chlorinated esters. The relative retention times for compounds at the various column temperatures are given and the retention order on a polar and on a non-polar column discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02260284
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  • 82
    Digitale Medien
    Digitale Medien
    The structure and properties of n-octadecanol film present on the surface of a carbon-silica adsorbent (1982)
    Springer
    Chromatographia 15 (1982), S. 517-520 
    Details
    ISSN: 1612-1112
    Schlagwort(e): Gas chromatography ; Carbon-silica adsorbents ; n-Octadecanol film ; Phase transitions
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Summary The properties of the n-octadecanol film on carbon-silica adsorbent (Carbosil) were investigated. It was found that n-octadecanol forms an oriented film on the Carbosil's surface. If the surface of the basic silica gel is not completely covered with carbon, then the phase transition takes place in this film at a temperature higher than the melting temperature of n-octadecanol. One may distinguish two forms of this film, characterised by the different structures and the temperatures of the phase transitions. The first exists on the surface of silica gel unblocked by carbon. This part of the film is a monolayer, in which the alcohol molecules are vertically oriented. The solid compact-liquid expanded type phase transition at the well-defined temperature occurs in this film. In the second part of the film formed on the carbon surface, there is a multilayer of n-octadecanol. Its molecules are probably parallely oriented in relationship to the adsorbent surface. This film desintegrates progressively when the temperature increase. Maximum temperature of this phase transition is lower than the temperature of its analogue on pure silica gel surface.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02260287
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  • 83
    Digitale Medien
    Digitale Medien
    Quantitative capillary gas chromatographic analysis (1982)
    Springer
    Chromatographia 15 (1982), S. 546-558 
    Details
    ISSN: 1612-1112
    Schlagwort(e): Gas chromatography ; Capillary columns ; Quantitative analysis ; Sample inlet systems ; High-speed analysis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Summary The attainment of precise quatitative analytical data using open-tubular (capillary) columns in standard, commercially available gas chromatographic instrumentation is demonstrated. Key elements in the design and proper utilization of the instrumentation are discussed. The function of the various sample introduction systems is elaborated and their quantitative performance demonstrated. The extra-column contribution to band-spreading is determined and the resultant data is used assessing the suitability of commercial instrumentation for highspeed capillary gas chromatography. The quantitative analysis of a sample containing some eleven components in less than thirty seconds is shown.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02280373
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  • 84
    Digitale Medien
    Digitale Medien
    Crystal hydrates: an investigation of the use of crystal hydrates as stationary phases in gas chromatography (1982)
    Springer
    Chromatographia 16 (1982), S. 126-131 
    Details
    ISSN: 1612-1112
    Schlagwort(e): Gas chromatography ; Crystal hydrates as stationary phases ; Mobile Phases containing water ; Selective retentions
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Summary The use of crystallohydrates, crystallohydrate solutions and melts as stationary phases in gas chromatography has been proposed. Crystallohydrates have been shown to display high selectivity in the separation of polar organic compounds when use is made of water vapours as the mobile phase. Some aspects of gas-liquid chromatography in water vapours and with the stationary phase comprising crystallohydrates have been studied, and the preliminary results obtained point to the desirability of further progress in this field.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02258882
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  • 85
    Digitale Medien
    Digitale Medien
    Phenols in whisky (1982)
    Springer
    Chromatographia 16 (1982), S. 201-203 
    Details
    ISSN: 1612-1112
    Schlagwort(e): Phenols ; Whisky ; Gas chromatography ; Aroma compounds
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Summary Twelve volatile phenols were identified in whisky by combined gas chromatography-mass spectrometry. Of these phenols 2,4-dimethylphenol was found for the first time in the aroma of whisky. The content of phenol, o-, m-, and p-cresol, guaiacol, p-ethylphenol, p-ethylguaiacol and eugenol in whiskies originating from different countries was determined by gas chromatography as their 2,4-dinitrophenyl ethers using electron capture detection. The results show that Scotch whiskies differ from others in the content of o-, m-, and p-cresol. The odour threshold values of phenols studied were determined in a 10% (v/v) ethanol-water mixture and in some cases also in the whiskies. Cresols have been found to make contribution to the aroma of Scotch whisky.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02258900
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  • 86
    Digitale Medien
    Digitale Medien
    From gas chromatography to gaia (1982)
    Springer
    Chromatographia 16 (1982), S. 26-31 
    Details
    ISSN: 1612-1112
    Schlagwort(e): Gas chromatography ; Ionization detectors ; Gaia
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Summary This paper is an account of the development of the gaia hypothesis as seen through the eyes of a gas chromatographer. Gaia is a radical notion about the Earth which postulates the climate and chemical composition to be regulated at an optimum by and for life. Gas chromatography played an important role in the gathering of evidence for the hypothesis but most significantly the art of inventing detectors lead to the developement of a planetary life detector through which gaia was revealed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02258864
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  • 87
    Digitale Medien
    Digitale Medien
    Hydrocarbon type analysis by gas chromatograph using a single capillary column and a multi-column valve system (1982)
    Springer
    Chromatographia 16 (1982), S. 282-285 
    Details
    ISSN: 1612-1112
    Schlagwort(e): Gas chromatography ; Naphtha analysis ; Gasoline analysis ; Hydrocarbon type analysis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Summary Two different gas chromatographic methods are used for the determination of hydrocarbon type distribution in naphtha and gasoline samples with final boiling points up to 275 °C. The methods are based either on a single capillary column or on a valve-switched packed column system. Both methods give extensive information on paraffins, olefins, naphthenes and aromatics in total as well as by carbon-number. In each case the analysis is fully automated with a computer controlling the entire analysis from injection to results presentation. The advantages and limitations of both methods are discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02258920
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  • 88
    Digitale Medien
    Digitale Medien
    Trace analysis of free hydroxyacids by gas chromatography (1982)
    Springer
    Chromatographia 16 (1982), S. 322-324 
    Details
    ISSN: 1612-1112
    Schlagwort(e): Gas chromatography ; Graphitized carbon black supports ; Determination of hydroxyacids
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Summary Acid-washed graphitized carbon black (Carbopakc B) modified with trimesic adic and PEG 20M has proved to be effective for quantitative analysis of underivatized low molecular weight hydroxyacids. Calibration data revealed good linear relationships between relative peak area and concentration for lactic and 3-hydroxybutyric acids down to 0.05 mmol/l. The packing material was suitable for the analysis of aqueous solutions of hydroxyacids as it is tolerant to injections of water over a prolonged period of use. The GC system developed has been applied to the analysis of some hydroxyacids of biomedical interest in blood plasma and lactic acid contained in wine and beer.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02258930
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  • 89
    Digitale Medien
    Digitale Medien
    Trace determination of amines and other nitrogen containing compounds with a modiefied thermal energy analyzer (TEATM) (1982)
    Springer
    Chromatographia 16 (1982), S. 354-358 
    Details
    ISSN: 1612-1112
    Schlagwort(e): Gas chromatography ; Modified thermal energy analyzer ; Selective detection of nitrogen compounds
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Summary A modification to the TEATM Analyzer is described, which allows it to be used as a highly selective GC detector for nitrogen compounds as well as for N-nitrosamines and nitro compounds. The modified Analyzer is as sensitive as the AFID, but has a much higher selectivity towards nitrogen compounds than the AFID. Its response appears to be molar, with an output that is dependent only on the number of nitrogen atoms present. The performance of the modified Analyzer for the analysis of ammonia, amines,N-nitrosamines, nitriles and organonitro compounds is reported and discussed, as is its application to the detection of these compounds in bacon and beer samples.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02258937
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  • 90
    Digitale Medien
    Digitale Medien
    Gas chromatographic separation of ethanolamines and ethylene glycols without preliminary derivatization (1981)
    Springer
    Chromatographia 14 (1981), S. 601-602 
    Details
    ISSN: 1612-1112
    Schlagwort(e): Ethanolamines ; Ethylene glycols ; Direct separation ; Gas chromatography ; Short glass capillaries
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Summary An effective and rapid GC separation of ethanolamines, even in the presence of ethylene glycols, using short glass capillary columns is developed. No preliminary derivatisation of the sample is necessary. The separation is completed in 6 minutes.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02262893
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  • 91
    Digitale Medien
    Digitale Medien
    The determination of phenol in urine by enzymatic hydrolysis/headspace gas chromatography (1981)
    Springer
    Chromatographia 14 (1981), S. 507-509 
    Details
    ISSN: 1612-1112
    Schlagwort(e): Gas chromatography ; Headspace ; Phenol ; Urine ; Enzymatic hydrolysis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Summary A new method has been developed for the determination of phenol in urine in which the phenol conjugates are hydrolysed enzymatically and the liberated phenol is analysed by headspace chromatography. The results compare favourably with those obtained by the method of van Haaften and Sie in which acid hydrolysis is carried out in a heated GC precolumn. The enzymatic hydrolysis headspace technique appears to be very reliable and does not suffer from the disadvantages of precolumn acid hydrolysis.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02265629
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  • 92
    Digitale Medien
    Digitale Medien
    Evaluation of the working conditions of light adsorbents and their use as sampling material for the GC analysis of organic air pollutants in work areas (1982)
    Springer
    Chromatographia 15 (1982), S. 712-716 
    Details
    ISSN: 1612-1112
    Schlagwort(e): Graphizized carbon black traps ; Organic air pollutants ; Work areas ; Gas chromatography
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Summary The use of traps containing graphitized carbon black for the collection and pre-analysis of atmospheric pollutants in industrial areas is presented. The working conditions, in terms of trapping capability and effectiveness of release by thermal desorption are discussed. Some practical applications are also given.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02261891
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  • 93
    Digitale Medien
    Digitale Medien
    Comments on column characterization: A sulfur column (1981)
    Springer
    Chromatographia 14 (1981), S. 421-424 
    Details
    ISSN: 1612-1112
    Schlagwort(e): Gas chromatography ; Liquid sulfur ; McReynolds' constants
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Summary The McReynolds' constants for liquid sulfur as a stationary phase in gas-liquid chromatography (GLC) are presented. A simple graphical method of pattern analysis is used to indicate the uniqueness of the sulfur column as compared with other stationary liquid phases characterized by McReynolds. The limitations of using a single factor (as polarity) for the basis for the selection of GLC columns is discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02262878
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  • 94
    Digitale Medien
    Digitale Medien
    Trennung, Identifizierung und Bestimmung von Treibgasen und Lösungsmitteln in Aerosol-Produkten mittels Gas-Chromatographie (1981)
    Springer
    Chromatographia 14 (1981), S. 351-354 
    Details
    ISSN: 1612-1112
    Schlagwort(e): Gas chromatography ; Kováts retention indices ; Propellants ; Solvents ; Aerosol packs
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Summary A gas chromatographic method is described by which a nearly complete separation of all commonly used propellants and solvents and their identification and determination can be achieved in one step. The separation is by simple adsorption chromatography on columns packed with Porapak-T with a temperature program 100–180°C at 10°C/min. Kováts' retention indices have been calculated for isothermal conditions at 150°C respectively 100°C for the propellants, at 180°C for the solvents. An exact identification of the propellants and solvents by means of the Kováts' indices is practicable even in complex mixtures.
    Notizen: Zusammenfassung Es wird eine gas-chromatographische Methode angegeben, welche eine fast vollständige Auftrennung aller handelsüblichen Aerosol-Treibgase und Lösungsmittel und ihre Identifizierung und Bestimmung in einem Schritt gestatet. Die Trennung erfolgt durch reine Adsorptions-Chromatographie and Porapak T-Säulen bei 100–180°C mit einer Temperaturate von 10°C/min. Zur Bestimmung der Retentionsindices nach Kovats wurden die Treibgase isotherm bei 150°C bzw. 100°C, die Lösungsmittel bei 180°C aufgetrennt. Anhand der Kovats-Indices ist eine eindeutige Identifizierung der Treibgase und Lösungsmittel selbst in vielfältigen Gemischen möglich.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02259234
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  • 95
    Digitale Medien
    Digitale Medien
    Influence of Van der Waals' volume of ethers, esters, carbonyls and alcohols on retention in gas chromatography stationary phases of different polyrity (1982)
    Springer
    Chromatographia 15 (1982), S. 771-775 
    Details
    ISSN: 1612-1112
    Schlagwort(e): Gas chromatography ; Van der Waals' volume ; Polarity of stationary phase ; Retention index
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Summary Equations for Retention Index (I) versus Van der Waals, volume (Vw) on squalane are studied for alcohols, carbonyls, esters and ethers. Each equation includes linear and branching substances with different positions of the functional group in the carbon chain. The study is extended to stationary phases with polarities from 4.29 to 91.54 on the Tarjan et al. scale. Variations of the slope and origin ordinate values with the polarity of the stationary phase are discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02261375
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  • 96
    Digitale Medien
    Digitale Medien
    Fast analysis by gas chromatography (1982)
    Springer
    Chromatographia 15 (1982), S. 125-132 
    Details
    ISSN: 1612-1112
    Schlagwort(e): Capillary columns ; Fast analysis ; Gas chromatography ; Instrumental effects ; Optimization
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Summary The efficiency of fast GC columns depends largely on the quality of the chromatograph. A theoretical and experimental study shows the relative importance of the various phenomena involved and permits the optimization of a GC System. Extremely good performances, exceeding 2,500 plates per second have been routinely obtained.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02290445
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  • 97
    Digitale Medien
    Digitale Medien
    A rapid gas chromatographic method for the analysis of acidic fermentation products (1982)
    Springer
    Chromatographia 15 (1982), S. 180-182 
    Details
    ISSN: 1612-1112
    Schlagwort(e): Acidic fermentation products ; Characterisation ; Gas chromatography ; Methyl esters
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Summary A rapid and simple method for the identification of acidic fermentation products is described. Methyl esters of volatile and non-volatile acids are separated on a single chromatographic column. Retention time data for a number of acids are tabulated.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02261536
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  • 98
    Digitale Medien
    Digitale Medien
    Retention index, connectivity index and Van der Waals' volume of alkanes (GLC) (1982)
    Springer
    Chromatographia 15 (1982), S. 521-524 
    Details
    ISSN: 1612-1112
    Schlagwort(e): Gas chromatography ; Retention index ; Connectivity index ; Van der Waals' volume ; Alkanes
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Summary The relationships between retention index and Van der Waals' volume and between retention index and connectivity index have been studied for 58 different alkanes (C1−C9) on squalane. The correlation coefficient for the former is higher than for the latter. From these equations a linear relationship between Van der Waals' volume and connectivity index is obtained which indicates that the two parameters are equivalent. A simple method for calculating the Van der Waals' volume of alkanes is proposed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02260288
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  • 99
    Digitale Medien
    Digitale Medien
    An apparatus for manufacturing flexible fused silica columns for gas liquid chromatography. Part I. The drawing process (1982)
    Springer
    Chromatographia 15 (1982), S. 569-574 
    Details
    ISSN: 1612-1112
    Schlagwort(e): Gas chromatography ; Capillary columns ; Fused silica capillaries ; Capillary drawing ; Glass capillaries
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Summary A compact description is given of a simple and reliable method of drawing flexible fused silica capillary for gas chromatography. Some emphasis is given to the fact that the practices of drawing optical fibres should not be followed too slavishly so this leads to unnecessarily complicated and expensive equipment. Satisfactory capillary column silica tubing can be made with straightfoward extension of the method developed earlier for drawing thick walled capillary. A simple glass/silica hydrogen oxygen diffusion flame bumer is described for fusing the preform tubing at the draw point which is enclosed by a water cooled glass enclosure to trap evaporated silica and maintain the operation under dust free conditions. The uniformity of the capillary diameter is better than 5% which is adequate for most gas chromatographic purposes. The second part of the paper yet to be published will cover the methods developed for coating the capillary both internally and externally.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02280376
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  • 100
    Digitale Medien
    Digitale Medien
    New uses of thermionic ionization detectors in gas chromatography (1982)
    Springer
    Chromatographia 16 (1982), S. 107-111 
    Details
    ISSN: 1612-1112
    Schlagwort(e): Gas chromatography ; Thermionic ionization ; Catalytic flame ionization
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Summary A newly designed thermionic detector was operated in two modes of thermionic ionization detection (TID), and a third mode of catalytic flame ionization detection (CFID). Operating modes were varied by changing the composition of the electrically-heated thermionic/catalytic source, and the composition of gases supplied to the detector. A TID-2 source activated by a low concentration of Cs/ceramic was operated in a dilute H2/air environment and provided specific responses to nitrogen and phosphorus compounds. A TID-1 source activated by a high concentration of Cs/ceramic was operated in a N2 environment and provided very high specificities and picogram detectivities to compounds containing electronegative functional groups such as the NO2 group. A CFID source formed from Ni/ceramic was operated in a H2/air flame environment and provided universal responses to all organics with enhanced responses to some heteroatom compounds.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02258879
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