SAMPO for Windows is a high performance gamma spectrum analysis program. All the measurement, analysis and NAA phases can be done either under full interactive user control or user defined tasks can be used for automated measurement and analysis sequences including control of MCAs and sample changers. High resolution gamma-ray spectroscopy together with the possibility to resolve complex multiplets with high accuracy makesSAMPO very suitable for INAA. On the other hand, the possibility to automate analysis sequences allows its use effectively also in all routine NAA measurements.NAA inSAMPO is accomplished using comparative methods. Spectra of standards, flux monitors, controls and actual samples are analyzed normally to obtain the peak areas which are optionally corrected for decay. In the comparison the flux monitor results are used to correct for variations in the effective neutron flux. An optional irradiation position correction can also be applied. The controls are used to alarm for possible deviations in the results.The sophisticated spectrum analysis methods used together with the comparative NAA and monitors give accurate results limited by the systematic effects only. The Windows environment provides ease of use and further processing power is available through the interface to expert system identification of nuclides.
The results of neutron activation analysis (NAA) and inductively coupled plasma atomic emission spectrometry (ICP/AES) are compared for aluminium samples in the purity range from 99.7 to 99.998%. The advantages of each method towards the determination of 25 elements is discussed.
Authors:R. Zeisler, W. James, E. Mackey, R. Spatz, and R. Greenberg
The National Institute of Standards and Technology (NIST) is preparing a freeze-dried powdered bovine liver tissue Standard
Reference Material (SRM) to replace SRM 1577b Bovine Liver as the stock of this material was exhausted during 2006. Like the
original SRM 1577 issued in 1972, this renewal focuses on the key elements for diagnostic, nutritional, and toxicological
measurements that are important to medical, veterinary, and environmental sciences investigations. NIST’s approach for value
assignment included extensive characterization by neutron activation analysis (NAA). Difficulties in the determination of
some elements present at very low levels were overcome by use of radiochemical separations. Twentyone elements were characterized
in SRM 1577c by NAA. The previous materials, SRM 1577 and 1577b, served as quality control.
The calculation of uncertainty budgets is becoming a standard step in reporting analytical results. This gives rise to the need for simple, easily accessed tools to calculate uncertainty budgets. An example of such a tool is the Excel spreadsheet approach of Robouch et al. Here, we present an internet application which calculates uncertainty budgets for k0-NAA. The Web application has built in Literature values for standard isotopes and accepts as inputs fixed information such as the thermal to epithermal neutron flux ratio, as well as experiment specific data such as the mass of the sample. The application calculates and displays intermediate uncertainties as well as the final combined uncertainty of the element concentration in the sample. The interface only requires access to a standard browser and is thus easily accessible to researchers and laboratories. This may facilitate and standardize the calculation of k0-NAA uncertainty budgets.
Authors:Tian Weizhi, Ni Bangfa, Wang Pingsheng, and Nie Huiling
Certifications of trace elements in existing CRMs, especially biological CRMs, are far from satisfactory. Neutron activation analysis (NAA) for its inherent advantages combined with newly established parametric standardization, may contribute to improve this situation. The continuing progress of the hybrid extended k0-relative NAA technique developed in our laboratory is discussed. Examples are given to show the reliability of the method in certification of multielements. RNAA is still one of the best methods, or even the method of choice, in analysis at sub-g/g concentration levels. The suitability of the technique for this purpose has been studied through the determination of rare earth elements at ng/g concentration level in two Chinese biological CRMs using both RNAA and ICPMS. Sampling behaviors of multielements in CRMs have been studied by INAA in an effort to develop CRMs suitable for analysis with small sample sizes.
Instrumental neutron activation analysis (INAA) has been used at the research reactor of the Institute of Nuclear Techniques
for measuring different types of samples for many years. For standardization purposes, the single comparator method has been
applied. Since the theoretical basis of NAA is well understood, the sources of uncertainty can be well estimated, detailed
uncertainty calculations have been recently performed to meet the increasing demands for method validation. INAA was validated
by the analyses of sets of reference materials (RM), selectivity was controlled, accuracy and precision of the method as well
as linearity, detection limits and measuring ranges were determined. Under the conditions of QA/QC, NAA can meet the high
demands of trace element analysis.
Authors:M. Frontasyeva, S. Pavlov, and V. Shvetsov
Experience in applying conventional and epithermal neutron activation analysis for some challenging areas of life sciences
and material science is reviewed. For more than 30 years of its operation the radioanalytical complex REGATA at the IBR-2
reactor in Dubna has become a source of analytical data for the environmental studies, marine geology, biotechnology and medicine,
technological process of diamond and boron nitride synthesis, archaeology, nanomaterials, etc. In spite of competing non-nuclear
analytical techniques (AAS, ICP-ES, ICP-MS, etc.), the reactor neutron activation analysis (NAA) as a primary (ratio) method
continues to be the most powerful multielement analytical technique providing quantification of trace elements at ultralow
levels. Combined with modern statistical data treatment of large arrays of data, GIS (geographic information system) technologies,
electron scanning microscopy, tomography, and others, NAA serves to obtain actual, practical results resumed in the review.
The perspectives of using the upgraded reactor IBR-2M for analytical investigations are discussed.
Authors:M. Bacchi, E. Fernandes, E. França, and P. Bode
This work is focused at the demonstration of the overall adequacy of the procedures introduced in a Brazilian laboratory for conducting the k0-standardized NAA. Concentrations of 29 elements determined in certified reference materials of plants and geological matrices are evaluated. Most of the experimentally determined values agreed well with the reference data and no consistent bias could be attributed to the analytical system adopted.
A post-Ko study of parametric reactor NAA is described including the determination and applications of working KoS for non-1/V reactions151Eu(n,)152Eu and176Lu(n,)177Lu; parametric corrections for235U fission, threshold reaction and -spectral interferences; and parametric normalizations for different counting geometries. The analytical significance, the principles, the experimental confirmations, and the application examples of these methods are briefly introduced.
k0-NAA allows the simultaneous analysis of up-to 67 elements. Thek0 method is based on calculations using a special library instead of measuring standards. For an efficient use of the method,
the calculations and resulting raw data require optimized evaluation procedures. In this paper two efficient procedures for
nuclide identification and gamma interference correction are outlined. For a fast computation of the source-detector efficiency
and coincidence correction factors the matrix interpolation technique is introduced.