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  • 1
    Digitale Medien
    Digitale Medien
    Comparison between CP/MAS 13C-NMR and pyrolysis-GC/MS in the structural characterization of humins and humic acids of soil and sediments (1998)
    Springer
    Fresenius' journal of analytical chemistry 362 (1998), S. 299-306 
    Details
    ISSN: 1432-1130
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Abstract The chemical structure of humins (HUs) and humic acids (HAs) of terrestrial and marine environments was investigated by cross-polarization magic angle spinning 13C-nuclear magnetic resonance spectroscopy (CP/ MAS 13C-NMR) and pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). Samples of HUs and HAs were obtained from sediments of the Adriatic Sea, the Lagoon of Ravenna (Adriatic Sea) and the Bubano Lake as well as from an agricultural soil. HUs displayed pyrograms and NMR spectra different from those of related HAs. According to NMR spectra HUs were more aliphatic and contained fewer carboxyl groups than HAs, while pyrolysates of HUs were characterized by higher levels of products arising from carbohydrates and lower levels of lignin methoxyphenols with respect to HAs. The relative content of paraffinic carbons determined by NMR was in good agreement with the relative abundance of unbranched aliphatic hydrocarbons released by pyrolysis. Both techniques evidenced the importance of polymethylene structures in HUs.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s002160051078
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  • 2
    Digitale Medien
    Digitale Medien
    Chemical characterization of the black crust present on the stone central portal of St. Denis abbey (1997)
    Springer
    Fresenius' journal of analytical chemistry 357 (1997), S. 1211-1214 
    Details
    ISSN: 1432-1130
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Abstract  A black crust sample from the stony central portal of the abbey of St. Denis, France, was analyzed by chromatographic and spectroscopic techniques to determine whether it was due to atmospheric pollution or to the degradation of a past restoration treatment. Stratigraphic surveys by optical microscopy, Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy/energy dispersive X-ray fluorescence (SEM/EDX) and pyrolysis/gas chromatography/mass spectrometry (PY/GC/MS) were consistent in ascribing the bulk of the crust to gypsum (CaSO4 ⋅ 2H2O) with inclusion of carbon particulate. The organic fraction was a minor constituent of the black crust. Hence, the deterioration by an organic substance used in the past to restore the building was ruled out.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s002160050333
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  • 3
    Digitale Medien
    Digitale Medien
    Fast atom bombardment mass spectrometry of polyphenols (syn. vegetable tannins) (1986)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 13 (1986), S. 449-468 
    Details
    ISSN: 1052-9306
    Schlagwort(e): Chemistry ; Analytical Chemistry and Spectroscopy
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Zusätzliches Material: 14 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/bms.1200130902
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  • 4
    Digitale Medien
    Digitale Medien
    Do ion trap and quadrupole lead to identical results in the analysis of terpenoic compounds? (1989)
    New York, NY : Wiley-Blackwell
    Rapid Communications in Mass Spectrometry 3 (1989), S. 241-243 
    Details
    ISSN: 0951-4198
    Schlagwort(e): Chemistry ; Analytical Chemistry and Spectroscopy
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Physik
    Notizen: The ion trap detector (ITD) is effective in the analysis of terpenoic mixtures from essential oils. ITD spectra are compared in library searches with spectra from a quadrupole mass spectrometer. ITD generally leads to lower FIT values, although its efficiency in terms of structural identification is comparable to that of quadrupolar systems.
    Zusätzliches Material: 1 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/rcm.1290030710
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  • 5
    Digitale Medien
    Digitale Medien
    Characterization of lignocellulosics by pyrolysis-gas chromatography-ion trap detection (1990)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 13 (1990), S. 52-55 
    Details
    ISSN: 0935-6304
    Schlagwort(e): Pyrolysis ; Gas chromatography ; Mass spectrometry ; Lignocellulose analysis ; Chemistry ; Analytical Chemistry and Spectroscopy
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Wheat straw lignins obtained by HF, H2SO4, HCL, NaOH, and dioxane/water extraction methods and native wheat straw were subjected to pyrolysis-gas chromatography (Py-GC). Pyrolytic fragments were tentatively identified by mass spectrometry using an on-line Py-GC-Lon Trap Detector (Py-GC-ITD) and their origin could be attributed to polysaccharides and lignin. Quantitation of fourteen main peaks common to all pyrograms showed statistically significant differences depending on lignin preparation. Pyrograms of typical lignin preparations, native wheat straw, and pure cellulose and ITD mass spectra are reported.
    Zusätzliches Material: 5 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/jhrc.1240130111
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  • 6
    Digitale Medien
    Digitale Medien
    HPLC characterization of phenolics in lignocellulosic materials (1988)
    Springer
    Chromatographia 26 (1988), S. 191-196 
    Details
    ISSN: 1612-1112
    Schlagwort(e): Column liquid chromatography ; Electrochemical detector ; Phenolics ; Lignocellulosic materials
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Summary The application of HPLC with an electrochemical detector for the determination of phenolics in lignocellulosic materials is reported. The separation of phenolic acids and aldehydes (gallic acid, p-hydroxybenzoic acid, vanillic acid, p-coumaric acid, syringic acid, ferulic acid, vanillin, syringaldehyde and p-hydroxybenzaldehyde) on two different columns (reversed phase C6 and styrene-divinylbenzene PLRP-S) is shown. Chromatograms of phenolic compounds in neutral, basic and oxidative extracts of wheat straw treated with NaOH and white rot fungusStropharia rugosoannulata are reported along with quantitative results.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02268150
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  • 7
    Digitale Medien
    Digitale Medien
    HPLC determination of catabolic amines in silage using their dansyl derivatives and an electrochemical detector (1989)
    Springer
    Chromatographia 27 (1989), S. 216-220 
    Details
    ISSN: 1612-1112
    Schlagwort(e): Column liquid chromatography ; Electrochemical detector ; Amines ; Silages ; Feedstuffs
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Summary The use of the electrochemical detector (EC) in the high performance liquid chromatography (HPLC) of dansyl derivatives of biogenic amines is reported. Isocratic and gradient elution patterns of synthetic mixtures of putrescine, cadaverine, 1,6-diaminohexane, tryptamine, histamine, tyramine, spermine and spermidine on a reversed phase column are shown. Hydrodynamic voltammograms of standard compounds are presented. The detection limits of the EC are compared with those of ultraviolet and spectrofluorimetric detectors. A chromatographic profile of amines from the proteolytic catabolism of maize silage byClostridia is shown.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02260449
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  • 8
    Digitale Medien
    Digitale Medien
    Use of analytical pyrolysis to characterize Egyptian painting layers (1995)
    Springer
    Chromatographia 40 (1995), S. 594-600 
    Details
    ISSN: 1612-1112
    Schlagwort(e): Pyrolysis-gas chromatography-mass spectrometry ; Fourier-transform infrared spectroscopy ; Ancient Egyptian painting media ; Egyptian sarcophagus
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Summary An Egyptian wooden sarcophagus and a cartonnage (664–525 B.C.) were subjected to pyrolysis-gas chromatography-mass spectrometry (PY-GC-MS) and Fourier-transform infrared spectroscopy (FT-IR) in order to characterize pigments and organic binding media. The aim of these investigations is to acquire a better knowledge of the painting technique used in ancient Egypt. Results showed that PY-GC-MS offered a rapid tool to discriminate between wax-based- and animal protein-based binders and to recognize the use of mixtures of the two products. FT-IR corroborated the pyrolysis findings, but sometimes provided less unequivocal results than PY-GC-MS. As an additional benefit, PY-GC-MS allowed the identification of a yellow pigment as the arsenic sulphide orpiment by means of the volatile As4 among the pyrolysis fragments.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02290274
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