Cyclic neutron activation analysis method was conducted for determination of Se in food samples. High accuracy and good precision
were proved by analyzing certified reference materials (CRMs) of chicken (GBW10018), rice (GBW10010) and cabbage (GBW10014).
The detection limits for the three CRMs reached 0.16, 0.66 and 1.2 ng after 6 cycles at the 161.9 keV γ-peak from 77mSe, under a neutron flux of 9.0 × 1011 n cm−2 s−1 and the conditions of 30 s irradiation, 2 s decay, 30 s counting and 2 s waiting, significantly lower than those of conventional
neutron activation analysis without any cycles, which were 0.94, 3.6 and 4.3 ng, respectively.
Authors:H. Dung, M. Freitas, S. Sarmento, M. Blaauw, and D. Beasley
A new Compton suppression system (CSS) for the gamma-ray spectrometer portion of the neutron activation analysis (NAA) was
set up at the RPI/ITN. The pneumatic transfer system, SIPRA, for short-lived nuclides and cyclic irradiations was improved.
A full calibration procedure of the CSS and SIPRA systems was performed. Two certified reference materials, NIST-SRM-1572
(Citrus Leaves) and NIST-SRM-1633a (Coal Fly Ash) were analyzed using the calibration factors. The CSS was instrumental in
lowering the detection limits of Cr, Fe, Hg, Rb, Sr, Th and Zn by reducing background and/or spectral interference considerably.
The analytical results were evaluated by comparison to the NIST certified values with deviations ranging from 2% to 8% for
the above mentioned elements, except Zn ranging from 10% to 15% for biological and environmental samples, respectively.
Authors:Z. Varga, G. Surányi, N. Vajda, and Z. Stefánka
A rapid and simple sample preparation method for plutonium determination in environmental samples by inductively coupled plasma
sector field mass spectrometry (ICP-SFMS) and alpha-spectrometry is described. The developed procedure involves a selective
CaF2 co-precipitation for preconcentration followed by extraction chromatographic separation. The proposed method effectively
eliminates the possible interferences in mass spectrometric analysis and also removes interfering radionuclides that may disturb
alpha-spectrometric measurement. For 239Pu, 240Pu and 241Pu limits of detection of 9.0 fg·g−1 (0.021 mBq), 1.7 fg·g−1 (0.014 mBq) and 3.1 fg·g−1 (11.9 mBq) were achieved by ICP-SFMS, respectively, and 0.02 mBq by alpha-spectrometry. Results of certified reference materials
agreed well with the recommended values.
The determination of the hydrogen concentrations in coal and metal samples were investigated by using the PGAA system at the
HANARO Research Reactor, KAERI. The calibration curve of the hydrogen concentration was obtained from a standard sample and
the effects of the interference peaks near the gamma-energy region of hydrogen were investigated. The background in the hydrogen
peak of a prompt gamma-ray spectrum was measured for the sample chamber and shielding materials of an atmospheric state. The
combined uncertainties estimated for the analysis procedure were in the range of 4–5%. Two kinds of certified reference materials,
NIST SRM 1632c (Coal), NIST SRM 173c (Titaniumbase Alloy) and NIST SRM 2453 (Titanium Alloy) were used to verify the accuracy
and precision of the measurement. The relative error was in the range of 3–6% and the relative standard deviation were less
Authors:H. Cho, K. Chun, K. Park, Y. Chung, and H. Kim
In the boron neutron capture therapy, an accurate determination of the boron content in a biological sample is very important.
The boron content was investigated with a standard solution of boron which was administered intraperitoneally with a dose
of 750 mg/kg body weight into mice induced cancer cells and tumors. The boron content for two types of a sample was compared
to the boronophenylalanine for the tumor and the ethylamine derivatives for the induced cancer cell, which were also investigated
for their accumulation rate in each organ such as blood, spleen, liver, kidney and brain. An analytical quality control was
carried out by using certified reference materials such as Peach Leaves, Apple Leaves and Spinach Leaves. The relative error
of the measured values was in good agreement within 2% to the certified values.
Authors:C. Chéry, S. Herremans, V. Van Lierde, F. Vanhaecke, M. Freitas, and R. Jasekera
Spices were analyzed by ICP-MS for determination of the ultra-micro trace elements in the human adult, Bi, Cd, Co, Ni, Pd,
Pt, Se, Sn, Te, Tl, to complement previous results obtained by INAA and by EDXRF. The spices, originating from Sri Lanka,
were curry, chilli powder and turmeric powders, coriander, cinnamon, black pepper, fennel, rampeh and curry leaves, and cumin.
The analytical procedure was validated by analyzing the certified reference materials NIST SRM 1572 Citrus Leaves and NIST
SRM 1573 Tomato Leaves. The results indicate that spices may contribute well to the daily optimal uptake of nutrients of a
human adult. The adequacy of spices as a reference material with certified ultra micro trace elements is suggested.
Authors:W. Goerner, O. Haase, M. Ostermann, and Chr. Segebade
C, N, O, F and P can be analyzed by instrumental photon activation analysis (IPAA) including decay curve analysis. The interference
of 30P (T1/2 = 149.9 s) by 15O (T1/2 = 122.2 s) can be ruled out by direct positron measurement making use of the largely different maximum β+-energies of both nuclides (3.24 MeV and 1.73 MeV, respectively). Interference by carbon (11C) can be avoided by sub-threshold activation with 17 MeV bremsstrahlung. The short half-life of 30P allows a high productivity of the method. Reliability was demonstrated in the range of 0.2%–2% P (detection limit = 40 μg/g).
Analysis of a certified reference material (BCR-CRM 063) yielded excellent agreement with the certified data.
The three-stage BCR sequential step reference extraction procedure was applied to the reference material BCR CRM 601, especially
developed for fractionation studies. Extracted fractions were analyzed for Cr, Ni, Zn, Cd, and Pb, by k0-standardized instrumental neutron activation (k0 INAA) and proton induced X-ray emission (PIXE), and flame atomic absorption spectrometry (FAAS). Sample preparation procedures
were developed for both k0 INAA and PIXE techniques, related to the evaporation of the solutions in order to get solid samples for neutron and proton
irradiation. Quality control was assessed by intercomparison of the analytical results obtained by the applied techniques,
which included results for a few certified reference materials. In the extracted fractions, chromium concentration was not
determined accurately by both nuclear techniques. Concerning Cd, Ni, Pb, and Zn, the results were in general in good agreement
with the certified values and FAAS. Some incomplete separation of the residue might have occurred.
Authors:H. Bounouira, A. Choukri, R. Cherkaoui, A. Gaudry, R. Delmas, C. Mariet, O. Hakam, and S. Chakiri
Instrumental neutron activation analysis (INAA), inductively coupled plasma-mass spectrometry (ICP-MS) and inductively coupled
plasma-atomic emission spectrometry (ICP-AES) were used for the determination of major and trace elements in sediment samples
of the Bouregreg river (Morocco). The reliability of the results was checked, by using IAEA Soil-7 certified reference material.
Results obtained by the three techniques were compared to control digestions efficiencies. A general good agreement was found
between INAA and both ICP-MS and ICP-AES after alkaline fusion (ICPf). The ICP-MS technique used after acid attack (ICPa)
was satisfactory for a few elements. A principal component analysis (PCA) has been used for analyzing the variability of concentrations,
and defining the most influential sites with respect to the general variation trends. Three groups of elements could be distinguished.
For these groups a normalization of concentrations to the central element concentration (that means Mn, Si or Al) is proposed.
Authors:J. Sterba, M. Blaauw, G. Steinhauser, M. Bichler, F. Grass, and G. Westphal
Combining the powers of a fast pneumatic transport system and the Automatic Activation Analyzer (AAA) of the Atominstitut
in Vienna with the newest version of the IAEA k0-Software, the application of the k0-method to the determination of short-lived radionuclides becomes easily possible. By calculating Asp-values with the IAEA
software, the often expensive and time-consuming measurement of Asp-values using certified reference materials is reduced
to quality control checks. Measurements clearly show that the two approaches are equivalent, especially since both take self-absorption
and neutron self-shielding into account. In this way it is possible to expand the library of the AAA with many hitherto unobtainable
Asp-values. At the same time, using highly accurate Asp-values already measured for many short-lived radionuclides, k0-values for those can be produced with a simple procedure.