ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Determination of the Tropospheric Hydroxyl Radical by Liquidphase Scrubbing and HPLC: Preliminary Results (2000)
    Springer
    Journal of atmospheric chemistry 36 (2000), S. 81-105 
    Details
    ISSN: 1573-0662
    Keywords: hydroxyl radical ; OH ; HPLC ; chromatography ; atmosphere ; air ; troposphere ; determination ; analysis ; air scrubbing ; scavenging ; fluorescence
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Geosciences
    Notes: Abstract A preliminary study was carried out toexamine the feasibility of measuring tropospherichydroxyl radicals (OH) by liquidphase scrubbing andhigh performance liquid chromatography (HPLC). Thepotential advantages of this approach are itssimplicity, portability, and low expense. Thesampling system employs glass bubblers to trapatmospheric OH into a buffered solution of salicylicacid (o-hydroxybenzoic acid, OHBA). Rapidreaction of OH with OHBA produces a stable fluorescentproduct, 2,5-dihydroxybenzoic acid (2,5-DHBA), whichis determined by reverse-phase HPLC and fluorescencedetection. Our preliminary field results indicatethat this method is most suitable for OH measurementsin clean tropospheric air, where interferences fromother atmospheric species appear to be negligible orminor relative to polluted air. In clean air, thesampling period is about 45–90 minutes, which yieldsa detection limit of approximately 3–6 ×105 radicalscm-3. During an OHintercomparison experiment at the Caribou samplingsite in Colorado, our liquidphase scrubber method wascompared with the ion-assisted mass spectrometry (MS)method. Our results were within the same range asthose of the ion-assisted MS method (1–5 ×106 radicals cm-3) within our precision atthat time (about ±30–50%). Preliminary testsin Pullman, WA indicated that the method might alsofunction in moderately polluted air by acidifying thescrubbing solution or by adding a scavenger tosuppress interferences. In Pullman, mid-day OHconcentrations were usually in the range of 2–20 ×106 radicals cm-3. Nighttime OHconcentrations were always low, either at or slightlyabove the detection limit.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1006313021834
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Mantle heat flow and geotherms for the main geologic domains in Morocco (1999)
    Springer
    International journal of earth sciences 88 (1999), S. 458-466 
    Details
    ISSN: 1437-3262
    Keywords: Key words Heat flow ; Pn velocity ; Radioactivity ; Geotherm ; Morocco
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences
    Notes: Abstract  Thermal and deep seismic soundings data are used to study the dependence between the compressional Pn velocity and the surface heat flow or the temperature at the Moho discontinuity in Morocco. This correlation indicates a significant decrease in Pn velocity where high heat flow and Moho temperature are observed. This result is consistent with respect to other regions of the world. Crustal heat generation models and geotherms are constructed for the major Moroccan geological domains extending from the Precambrian units in the south to the Alpine units in the north. The crustal contribution in surface heat flow is on average 35 mWm–2, with high values of 41–42 mWm–2 in the western and eastern Meseta where Hercynian granite intrusions could enrich the crust in radioactive heat sources. High mantle heat flow values are obtained beneath the Alboran neogene basin (62 mWm–2), the Rif (47 mWm–2), the Middle Atlas (41 mWm–2), and the south Atlantic margin (40 mWm–2) where the crust is thinned by an extensional tectonic regime. Despite their similar formation context, the intra-continental belts of the Middle and the High Atlas show different geothermal field components. A lithospheric heating process in the Middle Atlas could be the result of a Plio-Quaternary basaltic volcanism. Finally, the Precambrian basement of the Anti-Atlas like all the West African shield is a stable domain showing the lowest subsurface temperatures.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s005310050278
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Analysis of fossil pigments from algae and bacteria in meromictic Lake Fidler, Tasmania, and its application to lake management (1998)
    Springer
    Journal of paleolimnology 19 (1998), S. 1-22 
    Details
    ISSN: 1573-0417
    Keywords: fossil pigments ; meromixis ; Lake Fidler ; Tasmania ; HPLC ; Mass Spectrometry ; lake management ; algae ; bacteria
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geosciences
    Notes: Abstract Lake Fidler is an ectogenic meromictic lake with a monimolimnion maintained by periodic incursions of brackish water from the lower Gordon River estuary. A dam across the middle reaches of the Gordon River has restricted these incursions of brackish water and meromictic stability has rapidly declined. A palaeolimnological study was carried in order to assess the historical development of meromixis and the impact of the dam on the microbiological communities in the lake. Fossil pigments in a 17 m sediment core were analysed using reverse phase high performance liquid chromatography (rp-HPLC) and mass spectrometry (MS). In addition, taphonomic studies of pigment production, deposition and degradation in the water column and surface sediments were used to identify planktonic and benthic pigment degradation processes and constrain the stratigraphic interpretation. Results comparing the pigment composition of pelagic sediment traps and littoral surface sediments indicated that the core from the centre of the lake would permit a historical reconstruction of planktonic bacterial and algal communities. Marked increases in prokaryotic pigments ca 3500 yr B.P. suggested the possible colonisation of a chemocline by phototrophic bacteria. Further changes in chlorophyll: carotenoid ratios and changes in relative abundances of both chlorophyll a and bacteriochlorophyll c derivatives also indicated that a change in the depositional environment had occurred; possibly due to altered stratification or anoxia. From this we infer the onset of either intermittent or permanent meromixis. Further increases in prokaryotic pigment abundance suggested that the present state of permanent meromixis was firmly established by 2070 ±50 14C yr B.P., and diatom analysis confirmed the development of a stable mixolimnion. High resolution studies of the top 10 cm of sediments measured pigments in mean concentrations of 15.1 ng g-1 with a mean S.D. of only 2.78 indicating little change in pigment abundance since the construction of the dam. Thus, Lake Fidler still retains most of the features of meromixis. However, evidence from nearby Lake Morrison and Sulphide Pool has shown that any further declines in meromictic stability will cause a rapid reversion to holomixis. Palaeolimnological evidence from the early stages of meromictic development of Lake Fidler suggests that such reversion to holomixis may not permanently eliminate all the microbiological communities, and that, given time, they may return and prosper with re-establishment of a suitable chemocline. These studies will guide recommendations for a management strategy to prevent the further decay of meromixis in the Gordon River lakes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1007909018527
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Mass Spectrometry and reverse phase HPLC techniques for the identification of degraded fossil pigments in lake sediments and their application in palaeolimnology (1997)
    Springer
    Journal of paleolimnology 18 (1997), S. 335-350 
    Details
    ISSN: 1573-0417
    Keywords: palaeolimnology ; pigments ; massspectrometry ; HPLC ; carotenoids ; chlorophylls ; bacteriochlorophylls ; biomarkers
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geosciences
    Notes: Abstract Accurate identification of fossil pigments is essential if they are to be used as biomarker compounds in palaeolimnological studies. In recent years High Performance Liquid Chromatography (HPLC) has greatly enhanced the efficiency with which fossil pigments can be characterised and quantified. Using HPLC, undegraded pigments are typically identified through retention times, absorbance spectra and co-chromatography with authentic reference standards. However, lake sediments may also contain degraded pigments for which there are often no standards, and which may be difficult to identify using HPLC alone. In this study, we submitted HPLC fractions of fossil pigments and pigment derivatives collected from a meromictic lake in south west Tasmania, to a combination of Mass Spectrometry (MS) techniques including Electron Impact (EI) and static Liquid Secondary Ion MS (LSIMS) to identify their molecular ion characteristics and organic chemical composition. Mass Spectrometry permitted the detection of specific mass ions which were used to verify the identity of pigments and their derivatives. These included five carotenoids, chlorophyll a and derivatives, three previously described bacteriochlorophyll c derivatives with molecular weights of 770, 784, and 802, and two undescribed derivatives of bacteriochlorophyll c with molecular weights of 766 and 788. With these improved identifications we speculate on the pathways and modes of pigment degradation in the lake and asses the value of the degraded pigments as biomarkers. The use of MS permitted the identification of a greater number of signature pigments of algal and bacterial communities thus increasing the palaeolimnological value of the sediments. These methods are best applied in fossil pigment studies where there are a large number of unknown pigments and pigment degradation products, and where there are no authentic standards for co-chromatography. Practical suggestions for pigment MS are included in the discussion.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1007943119392
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Radon variations in a Hungarian village (1997)
    Springer
    Environmental geology 31 (1997), S. 123-127 
    Details
    ISSN: 1432-0495
    Keywords: Key words Geochemistry ; Porosity ; Radioactivity ; Radon
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences
    Notes: Abstract  A steady radon exhalation is assumed in most publications. In a village of North-East Hungary, however, high radon concentrations have been measured, differing strongly in neighbouring houses and varying in time, due to the interplay of geochemical phenomena.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002540050171
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    The detection and recognition of underground nuclear explosions (1995)
    Springer
    Surveys in geophysics 16 (1995), S. 495-532 
    Details
    ISSN: 1573-0956
    Keywords: Nuclear explosion detection and recognition ; Seismology ; Remote sensing ; Radioactivity ; Ionospheric effects
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract This paper reports on a joint meeting of the Royal Astronomical Society's Joint Association for Geophysics and VERTIC (the Verification Technology Information Centre) held in London in 1992. The topics presented focused on the detection and recognition of underground nuclear explosions. The objective of the meeting was to emphasize the multi-methodological approach that is important in verifying compliance with test-ban treaties. An overview of seismological monitoring was followed by a discussion of the technical and scientific aspects of a global seismic monitoring network, and in particular of the 1991 experiment to test the large-scale international exchange of seismic data between recording stations and data centres world-wide. The current capabilities of satellite remote-sensing were presented, and their use explained in terms of both the provision of information for monitoring the development of foreign nuclear testing programmes and also for providing sufficient information for the evaluation of treaty compliance. A review of radio-isotope sampling showed how the isotopic signature of both air and ground based sampling programmes can be diagnostic of the nuclear source. Finally, previously classified research on the ionospheric effects of underground nuclear explosions was presented, the generated acoustic waves disturbing the ionosphere and producing detectable changes in the reflection of radio and radar signals which have potential as a monitoring technique.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00665683
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Radioelement (U, Th, Rn) concentrations in Norwegian bedrock groundwaters (1995)
    Springer
    Environmental geology 25 (1995), S. 165-180 
    Details
    ISSN: 1432-0495
    Keywords: Groundwater ; Radioactivity ; Radon ; Uranium ; Thorium ; Norway ; Granite ; Drinking Water Standards
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences
    Notes: Abstract Twenty-eight samples of groundwater from bedrock boreholes in three distinct Norwegian geological provinces have been taken and analyzed for content of Rn, U, and Th, together with a wide variety of minor and major species. Median values of 290 Bq/1, 7.6 μg/1, and 0.02 μg/1 were obtained for Rn, U, and Th respectively, while maximum values were 8500 Bq/1, 170 μg/1, and 2.2 μg/1. Commonly suggested drinking water limits range from 8 to 1000 Bq/1 for radon and 14 to 160 μg/1 for uranium. Radioelement content was closely related to lithology, the lowest concentrations being derived from the largely Caledonian rocks of the Trøndelag area, and the highest from the Precambrian Iddefjord Granite of southeast Norway (11 boreholes) where median values of 2500 Bq/1, 15 μg/1 and 0.38 μg/1, respectively, were obtained. The Iddefjord Granite is not believed to be unique in Norway in yielding high dissolved radionuclide contents in groundwaters, and several other granitic aquifers warrant further investigation in this respect.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00768546
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Evidence for the biological turnover of thiols in anoxic marine sediments (1991)
    Springer
    Biogeochemistry 13 (1991), S. 117-135 
    Details
    ISSN: 1573-515X
    Keywords: mercaptans ; methanethiol ; Inhibitors ; BES ; 3-MPA ; adsorption ; HPLC ; nucleophiles ; sulfate-reducing bacteria
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Geosciences
    Notes: Abstract The concentrations of methanethiol (MSH) and 3-mercaptopropionate (3-MPA) increased for a period of up to 24 h in fresh slurries of anoxic Biscayne Bay sediments. Other endogenous thiols such as glutathione (GSH) deceased immediately after slurry preparation or were not detectable at all. The maximum concentrations reached by 3-MPA and MSH were sometimes as high as 1 μM, but were usually in the 100 to 300 nM range. After the initial increases, the concentrations of these thiols decreased rapidly to nearly constant levels of ∼20 nM for MSH and 〈 1nM for 3-MPA. In pre-incubated slurries, which had constant levels of thiols, the addition of microbial inhibitors including tungstate, molybdate, chloroform, and a mixture of chloramphenicol plus tetracycline caused MSH and 3-MPA to accumulate steadily. In the presence of inhibitors, accumulation rates of MSH ranged from 18 to 730 nM · d-1 and those of 3-MPA ranged from 0 to 185 nM · d-1. Tungstate and chloroform generally gave the highest accumulation rates, while molybdate gave the lowest, possibly due to its complexation with sulfhydryl compounds. BES (2-Bromoethanesulfonate) was also tested for its effects, but no 3-MPA and only trace amounts (19 nM · d-1) of MSH accumulated with this treatment. However, additions of BES (10 mM) to sulfidic sediments caused significant (∼8 μM · d-1) production of 2-mercaptoethanesulfonate (HS-CoM). Formation of HS-CoM was abiotic and was due to sulfide attack on the bromine atom in BES. The accumulations of 3-MPA and MSH in the presence of several different microbial inhibitors, suggests that these thiols may turn over in anoxic sediments. The relatively low concentrations of thiols observed in pore water profiles may be due to continuous microbial removal of these compounds. Much larger amounts of thiols were associated with sediment particles than present in the pore water. Evidence is presented which suggests that bound thiols may be exchangeable with the porewater, and therefore potentially available for microbial consumption.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00002773
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Hydrolysis of low-molecular-weight soil peptides by immobilized proteases in column and batch reaction systems (1990)
    Springer
    Biology and fertility of soils 9 (1990), S. 335-340 
    Details
    ISSN: 1432-0789
    Keywords: Amino acids ; HPLC ; Immobilized protease ; Organic matter fractions ; Peptides ; Soil nitrogen ; Soil enzymes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geosciences , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Organic matter was extracted from three soils, a cultivated Berwick sandy loam, a cultivated Franklin loamy sand, and an uncultivated Cumberland silty loam. Gel-permeation chromatography was used to separate organic matter extracts into high- (HMW) and low-molecular-weight (LMW) fractions. Reversed-phase high performance liquid chromatography was used to separate and collect the LMW peptide fractions. Peptide samples were hydrolyzed with immobilized proteases attached to beaded agarose and carboxymethyl cellulose in column and batch reaction systems. The chromatograms suggested that peptides are bound to common soil components. The amino acids released in the greatest percentages were relatively non-polar. Large percentages of serine, glycine, alanine, threonine, and valine were observed in the LMW soil peptides. Little aspartic acid, asparagine, glutamic acid, glutamine, arginine, and no histidine was detected in the LMW soil peptides. The soil peptides released different amino acid percentages and quantities when hydrolyzed by immobilized proteases attached to different supports. The quanitities of amino acids released by batch hydrolysis differed from those obtained with column hydrolysis. Greater quantities of amino acids were released (by both types of immobilized protease) from the LMW peptide hydrolysates of the two cultivated soils than from the uncultivated soil.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00634111
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    The simultaneous determination of muramic acid and glucosamine in soil by high-performance liquid chromatography with precolumn fluorescence derivatization (1988)
    Springer
    Biology and fertility of soils 6 (1988), S. 125-130 
    Details
    ISSN: 1432-0789
    Keywords: Muramic acid ; Glucosamine ; Soil ; HPLC ; Biomass
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geosciences , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary The optimal release and quantitative estimation of muramic acid and glucosamine were studied simultaneously in soil samples. The effect of hydrolysis conditions, HCl concentration, hydrolysis time, the ratio of soil dry weight to acid, and the recovery of reference substances were investigated. Derivatization of the fluorogenic reagent o-phthalaldehyde, in the presence of 2-mercaptoethanol with the residue of a soil hydrolysate, was achieved by optimizing the relative amounts of o-phthalaldehyde to hydrolysate in the reaction mixture, the pH of both, and the incubation period. A linear relationship was found between the fluorescence response and the concentration of the test substances. The muramic acid, as well as the glucosamine (o-phthalaldehyde) derivatives gave single peaks, and complete separation from interfering substances at the picomol level was achieved in a short time (3 h preparation and 30 min for chromatography) by using high-performance liquid chromatography.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00257661
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 11
    Electronic Resource
    Electronic Resource
    Chemical Characterization of Suspended Particulate Organic Matter by Pyrolysis-Gas Chromatography Coupled with Mass Spectrometry and High Performance Liquid Chromatography in the Bottom Nepheloid Layer of the Rhone Delta
    Amsterdam : Elsevier
    Estuarine, Coastal and Shelf Science 37 (1993), S. 221-236 
    Details
    ISSN: 0272-7714
    Keywords: HPLC ; PY-GC-MS ; Rhone delta ; bottom nepheloid layer ; organic matter ; phenols ; suspended material
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Biology , Geography , Geosciences
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1006/ecss.1993.1053
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 12
    Electronic Resource
    Electronic Resource
    The Mulhouse basin: evidence from porphyrin distributions for water column anoxia during deposition of marls
    Amsterdam : Elsevier
    Organic Geochemistry 20 (1993), S. 1217-1225 
    Details
    ISSN: 0146-6380
    Keywords: HPLC ; alkyl porphyrins ; anoxic conditions ; bacteriochlorophylls d ; evaporitic environments ; palaeoenvironmental assessment ; water column anoxia
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Chemistry and Pharmacology , Geosciences
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1016/0146-6380(93)90010-9
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 13
    Electronic Resource
    Electronic Resource
    Early chlorin diagenesis in a recent aquatic sediment
    Amsterdam : Elsevier
    Organic Geochemistry 10 (1986), S. 975-980 
    Details
    ISSN: 0146-6380
    Keywords: FAB-MS ; HPLC ; NMR ; chlorins ; chlorophylls ; diagenesis ; pheophytins
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Chemistry and Pharmacology , Geosciences
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1016/S0146-6380(86)80035-3
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...