% 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{Becker:39797,
      author       = {Becker, J. S. and Dietze, H.-J.},
      title        = {{A}pplication of double-focusing field {ICP} mass
                      spectrometry with shielded torch using different nebulizers
                      for ultratrace and isotope analysis of long-lived
                      radionuclides},
      journal      = {Journal of analytical atomic spectrometry},
      volume       = {14},
      issn         = {0267-9477},
      address      = {Cambridge},
      publisher    = {ChemSoc},
      reportid     = {PreJuSER-39797},
      pages        = {1493 - 1500},
      year         = {1999},
      note         = {Record converted from VDB: 12.11.2012},
      abstract     = {The capability of double-focusing sector field ICP-MS with
                      a plasma-shielded torch using different nebulizers (a
                      Meinhard nebulizer with a Scott-type spray chamber with a
                      solution uptake rate of 1 ml min(-1); a MicroMist
                      microconcentric nebulizer used with a minicyclonic spray
                      chamber with a solution uptake rate of 0.085 ml min(-1); an
                      ultrasonic nebulizer with a solution uptake rate of 2 ml
                      min(-1); and a direct injection high-efficiency nebulizer
                      with a solution uptake rate of 0.085 ml min(-1)) for the
                      introduction of radioactive sample solutions into the ICP
                      was investigated. The total amount of analyte for each
                      long-lived radionuclide (Ra-226, Th-230, Np-237, U-238,
                      Pu-239 and Am-241; concentration of each was 1 ng l(-1) in
                      the aqueous solution) using different nebulizers was 5 pg
                      for the Meinhard nebulizer, 0.4 pg for the MicroMist
                      microconcentric nebulizer and 10 pg for the ultrasonic
                      nebulizer. The application of the shielded torch yielded an
                      increase in sensitivity for all these nebulizers of up to a
                      factor of 5 compared with the original configuration without
                      a shielded torch. Sensitivities of about 2000 MHz ppm(-1)
                      were measured for the radionuclides investigated (except for
                      Ra-226) using the MicroMist microconcentric nebulizer with a
                      shielded torch. The detection limits were in the sub-pg
                      l(-1) range and the precision ranged from 1 to $2\%$ RSD
                      (n=5) for the 1 ng l(-1) concentration level (0.4 pg sample
                      size). A further increase in sensitivity for long-lived
                      radionuclides of nearly one order of magnitude in comparison
                      with the MicroMist microconcentric nebulizer was observed
                      using ultrasonic nebulization, but the amount of analyte
                      required was significantly higher (by a factor of 25). In
                      contrast, the direct injection high-efficiency nebulizer
                      (DIHEN) in double-focusing sector field ICP-MS (DF-ICP-MS)
                      with a shielded torch resulted in a decrease in sensitivity
                      in comparison with the unshielded torch because of a higher
                      water load due to the direct injection of aqueous solution
                      into the plasma. At low solution uptake rates (down to
                      several mu l min(-1)), the uranium solutions were analyzed
                      by DIHEN-ICP-MS using a double-focusing sector field
                      instrument with higher sensitivity than quadrupole-based
                      ICP-MS. Flow injection was used for sample introduction to
                      measure small sample volumes of radioactive waste solutions
                      (20 mu l). The determination of Np-237 at a concentration of
                      10 ng l(-1) by flow injection DF-ICP-MS was possible with a
                      precision of $2.0\%$ (RSD, n=5). In order to avoid mass
                      spectral interferences and matrix effects long-lived
                      radionuclides (e.g., of U, Th and Tc-99) were separated from
                      the radioactive waste matrix by liquid-liquid extraction or
                      ion exchange. The methods developed for the precise
                      determination of the concentration and isotopic ratios of
                      long-lived radionuclides were applied to aqueous standard
                      solutions and radioactive wastes by double-focusing sector
                      field ICP-MS. The precision of Pu isotopic analysis by
                      double-focusing ICP-MS with a shielded torch was 0.2, 2 and
                      $14\%$ for 1000, 100 and 10 pg l(-1) (amount of analyte:
                      500, 50 and 5 fg), respectively.},
      keywords     = {J (WoSType)},
      cin          = {ZCH},
      ddc          = {540},
      cid          = {I:(DE-Juel1)ZCH-20090406},
      pnm          = {Entwicklung analytischer Verfahren},
      pid          = {G:(DE-Juel1)FUEK118},
      shelfmark    = {Chemistry, Analytical / Spectroscopy},
      typ          = {PUB:(DE-HGF)16},
      UT           = {WOS:000083077900031},
      doi          = {10.1039/a901762c},
      url          = {https://juser.fz-juelich.de/record/39797},
}