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@ARTICLE{Laumer:5094,
      author       = {Laumer, W. and Andreu, L. and Helle, G. and Schleser, G. H.
                      and Wieloch, T. and Wissel, H.},
      title        = {{A} novel approach for the homogenization of cellulose to
                      use micro-amounts for stable isotope analyses},
      journal      = {Rapid communications in mass spectrometry},
      volume       = {23},
      issn         = {0951-4198},
      address      = {New York, NY},
      publisher    = {Wiley Interscience},
      reportid     = {PreJuSER-5094},
      pages        = {1934 - 1940},
      year         = {2009},
      note         = {Contract/grant sponsor: EU Project ISONET; contract/grant
                      number: EV K2-2001-00147.Contract/grant sponsor: German
                      Science Foundation (DFG); contract/grant number:
                      HE3089/1-Pirin.},
      abstract     = {Climate reconstructions using stable isotopes from
                      tree-rings are steadily increasing. The investigations
                      concentrate mostly on cellulose due to its high stability.
                      In recent years the available amount of cellulose has
                      steadily decreased, mainly because micro-structures of plant
                      material have had to be analyzed. Today, the amounts of
                      cellulose being studied are frequently in the milligram and
                      often in the microgram range. Consequently, homogeneity
                      problems with regard to the stable isotopes of carbon and
                      oxygen from cellulose have occurred and these have called
                      for new methods in the preparation of cellulose for reliable
                      isotope analyses. Three different methods were tested for
                      preparing isotopically homogenous cellulose, namely
                      mechanical grinding, freezing by liquid nitrogen with
                      subsequent milling and ultrasonic breaking of cellulose
                      fibres. The best precision of isotope data was achieved by
                      freeze-milling and ultrasonic breaking. However, equipment
                      for freeze-milling is expensive and the procedure is
                      labour-intensive. Mechanical grinding resulted in a rather
                      high loss of material and it is also labour-intensive. The
                      use of ultrasound for breaking cellulose fibres proved to be
                      the best method in terms of rapidity of sample throughput,
                      avoidance of sample loss, precision of isotope results, ease
                      of handling, and cost.},
      keywords     = {Carbon Isotopes: analysis / Cellulose: chemistry / Freezing
                      / Oxygen Isotopes: analysis / Physics: economics / Physics:
                      methods / Ultrasonics / Carbon Isotopes (NLM Chemicals) /
                      Oxygen Isotopes (NLM Chemicals) / Cellulose (NLM Chemicals)
                      / J (WoSType)},
      cin          = {ICG-4 / ICG-2 / ICG-3 / ICG-5},
      ddc          = {530},
      cid          = {I:(DE-Juel1)VDB793 / I:(DE-Juel1)VDB791 /
                      I:(DE-Juel1)VDB142 / I:(DE-Juel1)VDB143},
      pnm          = {Terrestrische Umwelt / Atmosphäre und Klima},
      pid          = {G:(DE-Juel1)FUEK407 / G:(DE-Juel1)FUEK406},
      shelfmark    = {Biochemical Research Methods / Chemistry, Analytical /
                      Spectroscopy},
      typ          = {PUB:(DE-HGF)16},
      pubmed       = {pmid:19504486},
      UT           = {WOS:000267458300007},
      doi          = {10.1002/rcm.4105},
      url          = {https://juser.fz-juelich.de/record/5094},
}