Filtern
Erscheinungsjahr
Dokumenttyp
- Zeitschriftenartikel (30)
- Beitrag zu einem Tagungsband (4)
- Posterpräsentation (4)
- Vortrag (3)
- Buchkapitel (1)
Schlagworte
- IDMS (7)
- TIMS (6)
- ICPMS (4)
- Reference materials (4)
- Isotope reference materials (3)
- Mass spectrometry (3)
- Atomic weight (2)
- Basidiomycetes (2)
- Cadmium (2)
- Delta reference materials (2)
- ICP-MS (2)
- IRM (2)
- IRMS (2)
- Milk (2)
- Nitrogen (2)
- Provenance studies (2)
- Stable isotopes (2)
- 15N2 fixation (1)
- 16S rRNA (1)
- Accelerator mass spectrometry (1)
- Analyte-matrix separation (1)
- Analytical uncertainty (1)
- Archaeometry (1)
- Authenticity (1)
- Biocide (1)
- Bodenanalyse (1)
- Boron isotope variations (1)
- Boron isotopes (1)
- Boron isotopes in food (1)
- Branching ratio (1)
- CRM (1)
- Calix[8]arenes (1)
- Casein standard (1)
- Cattle (1)
- Certification (1)
- Certified reference material (1)
- Comparability (1)
- Copper (1)
- Cu-64 (1)
- Dairy cows (1)
- Delta-RM (1)
- Delta-scale (1)
- Determination of metrology of new cadmium atomic weight (1)
- Diazotroph (1)
- ERM (1)
- Elemental analyser (1)
- Erythrocytes (1)
- FTIR-ATR spectroscopy (1)
- Faecal monitoring (1)
- Feed (1)
- Feeding regime (1)
- Fishmeal (1)
- Food (1)
- Fossil fuel (1)
- Full-factorial experimental plan (1)
- Fungal-bacterial interaction (1)
- Fungalbacterial interaction (1)
- Fungi (1)
- Heterocycles (1)
- Hypholoma fasciculare (1)
- ICP-IDMS (1)
- ICP-OES (1)
- INAA (1)
- Isotope (1)
- Isotope abundance (1)
- Isotope dilution (1)
- Isotope labeling (1)
- Isotope ratio (1)
- Isotopic Reference Material (1)
- Isotopic abundance variations (1)
- Isotopic composition (1)
- Königswasserextraktion (1)
- Low sulfur (1)
- MC-ICP-MS (1)
- Magnesium (1)
- Magnesium absorption (1)
- Measurement uncertainty (1)
- Metrology (1)
- Microbial interaction (1)
- Multi-collector ICP-MS (1)
- Multi-element screening (1)
- Multicollector inductively coupled plasma mass spectrometry (1)
- N2 assimilation (1)
- NTD (1)
- Neutron transmutation doping (1)
- Nickel (1)
- PLFA (1)
- Pb isotope ratio thermal ionization mass spectrometry (1)
- Phosphates (1)
- Primary Isotopic Reference Material (1)
- Proteobacteria (1)
- Provenance (1)
- RBS (1)
- Reference material (1)
- Reference procedure (1)
- Review (1)
- S K-edge X-ray absorption near edge spectroscopy (XANES) (1)
- SF-ICP-MS (1)
- SY-XRF (1)
- Schwermetallbestimmung (1)
- Soil (1)
- Stable isotope (1)
- Stable isotope probing (1)
- Stereochemistry (1)
- Sulfate-esters (1)
- Sulfur oxidation status (1)
- Surface analysis (1)
- Synthetic isotope mixtures (1)
- Synthetic mixtures (1)
- Thermal ionization mass spectrometry (1)
- Traceability (1)
- Unsicherheitsvergleiche (1)
- Urinary monitoring (1)
- Urine (1)
- VPDB (1)
- Vario EL III (1)
- Water (1)
- Wood decomposing basidiomycetes (1)
- Wood decomposition (1)
- Wood preservative (1)
- XRF (1)
- Zinc (1)
- multi-collector (1)
- reference material (1)
- uncertainty budget (1)
Eingeladener Vortrag
- nein (3)
The neutron transmutation doping (NTD) of highly pure copper with zinc was investigated as a promising means of achieving controlled gradation of the zinc content in the range 1-20 wg g-1. The doping process leads to the enrichment of two stable isotopes 64Zn and 66Zn in a ratio which differs from that of natural isotopic distribution. Mass spectrometric investigations by thermal ionization mass spectrometry (TIMS) were performed to validate the results obtained by gamma spectrometry. The investigations included both determination of the isotopic ratios of the doped zinc isotopes and the analysis of the accumulated zinc contents by isotope dilution (ID) analysis. Thereby a sample-specific correction of the blank could be performed because the isotope 68Zn was not influenced, because of the transmutation process. The results obtained by TIMS prove the strict proportionality of the doped zinc content, in the range 5 to 20 wg g-1, to the neutron fluence. Comparison with gamma spectrometric results showed a very good agreement within the uncertainties.
A thin-layer reference material for surface and near-surface analytical methods was produced and certified. The surface density of the implanted Sb layer was determined by Rutherford backscattering spectrometry (RBS), instrumental neutron activation analysis (INAA), and inductively coupled plasma isotope dilution mass spectrometry (ICP-IDMS) equipped with a multi-collector. The isotopic abundances of Sb (121Sb and 123Sb) were determined by multi-collector ICP-MS and INAA. ICP-IDMS measurements are discussed in detail in this paper. All methods produced values traceable to the SI and are accompanied by a complete uncertainty budget. The homogeneity of the material was measured with RBS. From these measurements the standard uncertainty due to possible inhomogeneities was estimated to be less than 0.78% for fractions of the area increments down to 0.75 mm2 in size. Excellent agreement between the results of the three different methods was found. For the surface density of implanted Sb atoms the unweighted mean value of the means of four data sets is 4.8121016 cm-2 with an expanded uncertainty (coverage factor k=2) of 0.0921016 cm-2. For the isotope amount ratio R (121Sb/123Sb) the unweighted mean value of the means of two data sets is 1.435 with an expanded uncertainty (coverage factor k=2) of 0.006.
A comparison of different isotope dilution mass spectrometric (IDMS) procedures using inductively coupled plasma mass spectrometry (ICPMS) and thermal ionization mass spectrometry (TIMS) was carried out to examine the degree of equivalence between the used procedures in terms of requirements for reference material certification. The comparison was based on the measurement results and their uncertainties. The sample used in this study is a pure zinc metal to be certified by the Bureau Communie de Référence (BCR) for amount contents of different trace elements. This study focuses on cadmium and thallium. The TIMS values contributed to the certified values. To guarantee identical conditions as far as possible for the procedures under investigation, the samples were split into subsamples after spiking and digestion took place. Thus, every IDMS procedure started with an identical set of samples. In total, four different IDMS procedures and one external calibration procedure using internal standardization as an example of routine analysis were applied. The IDMS procedures divide in a group with and a group without trace/matrix separation. Multicollector TIMS (TI-MC-MS) and multicollector ICPMS (ICP-MC-MS) were used in combination with trace/matrix separation, whereas quadrupole ICPMS (ICP-QMS) and ICP-MC-MS were also applied to nonseparated samples. All IDMS results agree well within their combined uncertainties, while some results from the external calibration procedure do not. IDMS results obtained by ICPMS without separation are comparable to those obtained by TI-MC-MS with separation regarding precision and accuracy. The smallest uncertainties were achieved using ICP-MC-MS in combination with trace/matrix separation.
Messtechnik
(2002)
A layer of Sb atoms, implanted with an energy of 400 keV and a nominal dose of 5×1016 atoms/cm2 into a high purity silicon wafer, was certified for its areal density (atoms/cm2) using Rutherford backscattering spectrometry (RBS), instrumental neutron activation analysis (INAA) and inductively coupled plasma isotope dilution mass spectrometry (ICP-IDMS) and for its isotope ratio using INAA and ICP-IDMS. Excellent agreement between the results of the different independent methods was found. In the present work, the measurements of the homogeneity of the areal density of Sb, previously determined with RBS in spots having 1 mm diameter, are improved with synchrotron X-ray fluorescence analysis: Higher precision in even smaller sample spots allows to estimate a reduced inhomogeneity of the whole batch of samples of the order of only 0.4%. Thus the uncertainty of the certified value can further be reduced. Down to fractions of a chip with 0.3×0.4 mm2 area, the areal density is now certified as (4.81±0.06)×1016 Sb atoms/cm2, where the expanded uncertainty 0.06 (coverage factor k=2) corresponds to only 1.2%. The relative merits of the different analytical methods are discussed.
The ?- branching ratio of 64Cu was determined by investigating the resulting decay products in copper doped by neutron transmutation. The numbers of 64Zn and 64Ni atoms were analyzed using isotope dilution analysis combined with thermal ionization mass spectrometry. A ?- branching ratio of (38.06±0.30)% was obtained, which agrees with the study of Kawada (Appl. Radiat. Isot. 37 (1) (1986) 7) to a higher accuracy. However, our result differs from the value cited in the NUDAT database of (39.0±0.3)%.