Two fundamentally different standardization systems, widely used in the neutron activation analysis of archaeological ceramics and of other materials, have been intercompared using procedures of high precision. The results should permit data standardized under either system to be transformed to the opposite system. The two systems are generally known as the Asaro-Perlman standard and the BNL Six-Rocks standard.
Authors:M. Kolomi'tsev, T. Ambardanashvili, and V. Dundua
The possibility of preparation of comparison standards for activation analysis on a base of phenol-formaldehyde polymer has
been shown. This polymer contains only a small amount of neutron-sensitive impurities. The suggested standards may be prepared
in large amounts under laboratory conditions.
The evaluation of the accuracy of thin elemental standards produced by Micromatter Co., which are widely used for the calibration
of the detection sensitivity of PIXE analysis systems, is presented in terms of Rutherford scattering measurements of the
thickness of 68 standards covering a range of 59 different elements.
Authors:S. Homma-Takeda, Y. Nishimura, H. Iso, T. Ishikawa, H. Imaseki, and M. Yukawa
Microbeam analysis is used in biomedical and environmental sciences to determine the presence and concentration of trace elements.
However, quantitative analyses of biological samples are challenging because the chemical and physical compositions of existing
standards differ from those typically encountered in biological samples. We developed a thin standard using polyvinyl alcohol
and assessed its quality by microbeam scanning particle induced X-ray emission (micro-PIXE) analysis. The relationship between
metal concentration and X-ray intensity was linear for certain standards up to 500 μg·g−1. Using this new thin standard, micro-PIXE analysis of Zn content in samples of human hair agreed well with analysis performed
by inductively-coupled plasma mass spectrometry, validating the use of these new thin standards for quantitative mapping with
In order to achieve the highly accurate and precise multielement determination in environmental materials, the usefulness of the comparative standard provided by the processing method proposed previously for soil samples has been re-examined using calcareous loam soil, light sandy soil and river sediment as unknown samples. As a result, it was also demonstrated that concentrations of 15 trace elements in each sample can be determined effectively and reasonably.
The chemical homogeneity of 10 mg samples of the (U. S.) National Bureau of Standards standard reference material 1633a (coal flyash) was determined for several elements by instrumental neutron activation analysis. The homogeneity was tested for the purpose of using small samples of the flyash as a multielement comparator standard. For small sample masses the flyash may be unacceptably heterogeneous for Fe, Co, Ba, and perhaps As and Sb. Homogeneity is improved by grinding the flyash. For comparison, homogeneity data for USGS GSP-1 is also presented.
Various methods of preparing standards for activation analysis have been reported in the literature. This paper describes
the feasibility of preparing ion exchange resin based standards containing predetermined levels of ions. Using a solution
of known initial concentration of the ion, and given the value of its distribution coefficient, it is possible to predict
the resin concentration that will be obtained. Resins containing ppm levels of copper and manganese have been prepared and
their stabilities evaluated over a period of time. The feasibility of preparing a multielement standard has been studied with
five rare earth elements (La, Ce, Sm, Eu and Dy).
Because of the demand for higher sensitivity radionuclide measurements,atom counting technology will become an increasingly used modality in geo-and bio-studies, and process control operations. It is anticipated that requestsfor standards, intercomparisons and performance evaluations services willsurge in the near future. In anticipation of such requests, the state-of-the-artneeded to be assessed for proactive planning purposes. The results of a workshopfocused on these issues indicated that there are several ongoing standards,intercomparisons and performance evaluations thrusts which are expected toexpand in the future. Furthermore, new projects were planned and the Councilon Ionizing Radiation Measurements and Standards (Public and EnvironmentalRadiation Protection subcommittee) was proposed as an information coordinator.