% IMPORTANT: The following is UTF-8 encoded.  This means that in the presence
% of non-ASCII characters, it will not work with BibTeX 0.99 or older.
% Instead, you should use an up-to-date BibTeX implementation like “bibtex8” or
% “biber”.

@ARTICLE{Krachler:62615,
      author       = {Krachler, M. and Mohl, C. and Emons, H. and Shotyk, W.},
      title        = {{I}nfluence of digestion procedures on the determination of
                      rare earth elements in peat and plant samples by
                      {USN}-{ICP}-{MS}},
      journal      = {Journal of analytical atomic spectrometry},
      volume       = {17},
      issn         = {0267-9477},
      address      = {Cambridge},
      publisher    = {ChemSoc},
      reportid     = {PreJuSER-62615},
      pages        = {844 - 851},
      year         = {2002},
      note         = {Record converted from VDB: 12.11.2012},
      abstract     = {Analytical procedures for the determination of rare earth
                      elements (REE) in 250 mg aliquots of difficult-to-digest
                      peat and plant matrices by ICP-MS were developed. Three
                      different pressurised digestion approaches were tested for
                      this purpose, namely (i) closed vessel acid digestion on a
                      hot-plate at 180 degreesC, (ii) digestion in a microwave
                      high pressure autoclave at a temperature of 240 degreesC and
                      (iii) high pressure ashing (HPA) at a temperature of 320
                      degreesC. Acid mixtures for digestion contained concentrated
                      nitric acid (3-5 ml) alone or additions of hydrofluoric acid
                      (HF) or tetrafluoroboric acid (HBF4) at volumes of 0.05-1.0
                      ml. The selection of appropriate volumes of HF or HBF4 was
                      identified as a critical step in obtaining accurate results.
                      For several reasons, HBF4 is preferred in comparison with
                      the normally used addition of HF for the destruction of
                      siliceous matter in the samples investigated. The optimum
                      acid mixture consisted of 3 ml of HNO3 and 0.1 ml of HBF4.
                      High sample throughput (40 samples simultaneously in about 2
                      h) favours the microwave autoclave over the other two
                      digestion systems. An ultrasonic nebuliser (USN) with
                      membrane desolvation used for sample introduction reduced
                      the spectral interferences originating from oxide formation
                      of lighter REE and Ba to a negligible extent. Internal
                      standardisation with Rh and Re proved to be essential for
                      obtaining correct results. In this way, all REE could be
                      reliably quantified by USN-ICP-MS without applying any
                      mathematical correction equations. The accuracy of the
                      optimised procedures was assessed by the determination of
                      REE in digests of the certified reference material GBW 07602
                      Bush Branches and Leaves and of the candidate reference
                      material CRM 670 Aquatic Plant. The developed analytical
                      procedures were applied to the determination of REE in two
                      different peat matrices. Results for these peat samples
                      obtained by USN-ICP-MS showed good agreement with INAA
                      values. Strong fractionation of REE caused by the addition
                      of HF or HBF4 in excess, known as lanthanide contraction,
                      could be experimentally established, except for europium,
                      which revealed a different behaviour.},
      keywords     = {J (WoSType)},
      cin          = {ICG-III},
      ddc          = {540},
      cid          = {I:(DE-Juel1)VDB49},
      pnm          = {Chemie und Dynamik der Geo-Biosphäre},
      pid          = {G:(DE-Juel1)FUEK257},
      shelfmark    = {Chemistry, Analytical / Spectroscopy},
      typ          = {PUB:(DE-HGF)16},
      UT           = {WOS:000177254600015},
      doi          = {10.1039/b200780k},
      url          = {https://juser.fz-juelich.de/record/62615},
}