Authors:J. Kučera, M. Šimková, J. Lener, A. Mravcová, L. Kinova, and I. Penev
Vanadium was determined in adrenal gland, brain, ileum, kidney, liver, lung, muscle, myocard, skin, spleen, gonads, thyroid, and tibia of rats fed with normal diet and exposed to high vanadium doses in drinking water. Both radiochemical neutron activation analysis (RNAA) and instrumental neutron activation analysis (INAA) were employed. The RNAA procedure consisted in dry ashing samples prior to irradiation and vanadium separation from the irradiated samples by extraction with N-benzoyl-N-phenylhydroxylamine (BPHA) in toluene from 5 mol·l–1 HCl. Vanadium accumulation as a function of a type of the tissue, exposure time, sex of rats, and administration of V(IV) or V(V) was studied. For quality assurance purposes, the biological (standard) reference materials NBS SRM 1571 Orchard Leaves, NBS SRM 1577a Bovine Liver, IAEA H-4 Animal muscle, and Bowen's Kale were analyzed.
An extensive database of analytical results from a recent biological matrix Reference Material Characterization Campaign permitted an intercomparison of the performances of various methods among each other and with "true" best estimate concentration values established for these materials. Six different variants of neutron activation analysis (NAA) methods were employed including: instrumental neutron activation analysis, instrumental neutron activation analysis with acid digestion, neutron activation analysis with radiochemical separation, neutron capture prompt gamma activation analysis, epithermal instrumental neutron activation analysis, and neutron activation analysis with preconcentration. The precision and accuracy performance of NAA-based analytical methods are compared with three other major techniques, atomic absorption spectrometry (AAS), atomic emission spectrometry (AES) and mass spectrometry (MS) for 28 elements in 10 natural matrix materials.
Three botanical reference materials prepared by the National Bureau of Standards have been studied by neutron activation analysis
to evaluate their suitability with respect to the determination of vanadium in biological samples. Various decomposition methods
were applied in connection with chemical or radiochemical separations, and results for vanadium were compared with those found
by purely instrumental neutron activation analysis. Significantly lower results indicate losses or incomplete dissolution,
which makes SRM 1575 Pine Needles and SRM 1573 Tomato Leaves less satisfactory than SRM 1570 Spinach. A reference value of
1.15 mg/kg of this material is recommended, based on results from 3 different methods. All three materials are preferable
to SRM 1571 Orchard Leaves, while Bowen's Kale remains the material of choice because of its lower concentration.
Standard reference materials, normally used to check accuracy and precision of analytical methods or for interlaboratory comparisons,
are proposed for use as multielement irradiation standards in neutron activation analysis (NAA). The advantages are simplicity
of operation, and elimination of errors inherent in the preparation of a large number of synthetic standards at the trace
element level. Examples of the approach are illustrated in the analysis of geological materials, soils, sediments, meteorites,
lunar samples, coal and fly ash using the USGS diabase W-1 as the irradiation standard. Plant materials and animal tissue
are analyzed using NBS Orchard Leaves as the irradiation standard. Best values for four popular SRM's (W-1, Bowen's Kale,
Orchard Leaves, and Bovine Liver) are tabulated to facilitate further use of the proposed approach to multielement neutron
Authors:F. S. Tagliaferro, E. A. De Nadai Fernandes, and M. A. Bacchi
A random sampling was carried out in the coffee beans collected for the preparation of the organic green coffee reference
material in view of assessing the homogeneity and the presence of soil as impurity. Fifteen samples were taken for the between-sample
homogeneity evaluation. One of the samples was selected and 10 test portions withdrawn for the within-sample homogeneity evaluation.
Br, Ca, Co, Cs, Fe, K, Na, Rb, Sc and Zn were determined by instrumental neutron activation analysis (INAA). The F-test demonstrated that the material is homogeneous for Ca, Co, Cs, K and Sc, but not homogeneous for Br, Fe, Na, Rb and Zn.
Results of terrigenous elements suggested negligible soil contamination in the raw material.
Authors:R. Filby, G. Van Berkel, A. Bragg, A. Joubert, W. Robison, and C. Grimm
National Bureau of Standards residual fuel oil Standard Reference Materials, SRM 1619, 1620a, 1634a, and former SRM 1634 were analyzed for 20 trace elements by instrumental neutron activation analysis to determine whether these materials are suitable trace element standards for elements other than the 6 elements certified in SRM 1634a. The SRM 1634a is a suitable standard for Ni, V, Se, Na, Zn, As, Cr, Fe, Ce, Sm and La but Co, Ba, Nd, Cs, Eu, Sc, and Sb appear to be heterogeneously distributed and are probably present in mineral particulates. The SRM 1619 is a convenient standard for V and for low Ni content oils, but SRM 1620a does not appear to be a suitable standard for any trace element investigated.
This work has been motivated by the need to establish reference materials from locally available sources. Neutron Activation Analysis (NAA) with Ge(Li) detector has been used to determine 26 elements in seven homogeneous clay samples with a wide range of composition. Short half-life nuclides (10s-10 m) were used to assay Na, Mg, K, Tl, Al, V, Mn, Ba, Dy, Ca and U by a fast rabbit transfer system. The long-lived nuclides were used to assay Sc, Sm, Cr, Eu, Ce, Cs, La, Fe, Lu, Hf, Co, Rb, Ta, Sb, and Pa(Th) after decay of24Na. The approach was purely instrumental. The accuracy of the resutls was tested by atomic absorption spectrometriy (AAS).
Authors:M. Pham, M. Betti, P. Povinec, V. Alfimov, D. Biddulph, J. Gastaud, W. Kieser, J. López Gutiérrez, G. Possnert, J. Sanchez-Cabeza, and T. Suzuki
A certified reference material designed for the determination of 129I in seawater, IAEA-418 (Mediterranean Sea water) is described and the results of certification are presented. The median
of 129I concentration with 95% confidence interval was chosen as the most reliable estimates of the true value. The median, given
as the certified value, is 2.28 × 108 atom L−1 (95% confidence interval is (2.16–2.73) 108 atom L−1), or 3.19 × 10−7 Bq L−1 (95% confidence interval is (3.02–3.82) × 10−7 Bq L−1). The material is intended to be used for standardization procedures applied in accelerator mass spectrometric laboratories.
It is available in 1 L units and may be ordered via IAEA web side (www.iaea.org).
Authors:M. Pham, M. Betti, P. Povinec, M. Benmansour, R. Bojanowski, P. Bouisset, E. Calvo, G. Ham, E. Holm, M. Hult, C. Ilchmann, M. Kloster, G. Kanisch, M. Köhler, J. La Rosa, F. Legarda, M. Llauradó, A. Nourredine, J.-S. Oh, M. Pellicciari, U. Rieth, A. Rodriguez y Baena, J. Sanchez-Cabeza, H. Satake, J. Schikowski, M. Takeishi, H. Thébault, and Z. Varga
A new Reference Material (RM) for radionuclides in mussel (Mytilusgalloprovincialis) from the Mediterranean Sea (IAEA-437) is described and the results of the certification process are presented. Four radionuclides
(40K, 234U, 238U, and 239+240Pu) have been certified, and information values on massic activities with 95% confidence intervals are given for nine radionuclides
(137Cs, 210Pb(210Po), 226Ra, 228Ra, 228Th, 230Th, 232Th, 235U, and 241Am). Results for less frequently reported radionuclides (90Sr, 129I, 238Pu, 239Pu, and 240Pu) are also reported. The RM can be used for quality assurance/quality control of the analysis of radionuclides in mussel
samples, for the development and validation of analytical methods and for training purposes. The material is available in
200 g units.
The concentrations of 35 trace elements in the UNS-SpS glass sand reference material have been determined by instrumental neutron activation analysis involving short- and long-term irradiations. For analysis, the so-called absolute monostandard method was used, i.e. the concentrations were calculated from the measured gamma-activity and not by comparison with a reference sample of known composition. The results of up to 25 independent determinations are compared with the values given by UNS and other investigators. Most element contents agree well with the published values expecting K, Ga, and La, which will be discussed. Trace element contents for Cl, As, Br, Dy, and Au are reported for the first time.