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.
Authors:S. Al-Jobori, R. Itawi, A. Saad, K. Shihab, M. Jalil, and S. Farhan
As a part of the Iraqi Food Analysis Programme /I.F.A.P./ the concentration of Na, Mg, P, Cl, K, Ca, Zn, Se, Br, Rb and I in natural milk collected from different regions of Iraq, and in milk powder samples have been determined by using the NAA technique. It was found that except for the elements I, Rb and Br the concentration of the elements was approximately identical in both the natural milks and milk powders.
Authors:Ni Bangfa, Peng Lixin, Wang Pingsheng, and Tian Weizhi
Characterizations of three major parameters of Certified Reference Materials (CRMs) concentration values of multielements, homogeneities of multielements, and stabilities of the materials, were further studied by NAA. In the determinations of multielements in RMs, both relative and K0 (and its extension) standardizations were used in an effort to detect hidden systematic errors and expand the number of determinable elements. In the evaluations of multielemental homogeneities, double sampling constants as well as Ingamells' Ks and F-test were used to establish semi-quantitative expressions of sampling uncertainty vs. size and number of subsamples for given elements in given materials. For the investigation of the stabilities of certified values, K0 NAA is to be used in follow-up analyses to test variations of certified values and provide updated and/or newly determined data. The final goal is to make NAA a definitive method for multi-trace element certification, a reliable method for homogeneity characterization, and a reproducible method for stability test. Examples are given to show preliminary results on the above aspects.
Authors:Cibele Zamboni, Laura Oliveira, Luciana Kovacs, and Sabrina Metairon
In this study the neutron activation analysis (NAA) technique was applied to determine Ca and Mg in whole blood from inhabitants
of Brazil for the purpose of establishing concentration ranges indicative of sex and age. The initiative to perform these
measurements is related to the increase in heart disease. According to recent statistics from WHO, the average is one death
due to heart attack in Brazil, every five minutes. The measures were performed considering lifestyle factors (non-smokers,
non-drinkers and no history of toxicological exposure) of Brazilian inhabitants. A healthy group constituted of male (n = 94) and female (n = 84) blood donors, ages between 18 and 70 years and above 50 kg, was selected from the blood banks and hematological laboratories
of Brazil. The influence of sex was also investigated considering several age ranges (18–29, 30–40, 41–50, >50 years). The
results show significant differences when a comparison is made by sex and age and may be useful to identify or prevent clinical
diseases. These results emphasize the need to perform periodic evaluation of Ca and Mg in blood.
Taking advantages of nuclear analytical techniques (NATs) with non-destruction, multielement capability, small and estimable
uncertainties over a wide range of sample sizes, the sampling behavior of multielements for a home-made natural matrix material
was studied with sample sizes ranging from several hundred mg down to tenths ng, namely nine orders of magnitude, by a combination
of three NATs, neutron activation analysis (NAA), proton induced X-ray emission (PIXE) and synchrotron radiation X-ray flurescence
(SR-XRF), in an effort to explore a procedure for the development of certified reference materials (CRMs) suitable for quality
control of microanalysis. For accurately weighable sample sizes (>1 mg), sampling uncertainties for 13 elements were found
to be less than 1% by INAA. For sample sizes unable to be accurately weighed (<1 mg), PIXE and SR-XRF were used, respectively.
Sampling uncertainties were found to be less than 1% at sample sizes of tenth mg level for seven elements, and less than 10%
on ng levels for three elements. Considering these three elements have satisfied homogeneity (sampling uncertainty less than
10%) at ng sample size level, any one of them can be served as a “relative balance” in sampling behavior characterization
of multielements on sample size levels larger than ng (e.g., μg level). On this basis, sampling uncertainties for nine elements
were found to be less than 10% on μg sample size level by INAA. The results indicate that the matrix is eligible as a candidate
of CRMs suitable for quality control of solid sampling microanalysis.
Authors:Bangfa Ni, Zhanqin Yu, Pingsheng Wang, Gaokui He, Weizhi Tian, and Erkang Wang
Thirty two elements were determined in five pieces of presumed cosmic dust samples with the weights of 5 to 25 g by neutron activation analysis (NAA). All the interferences from fission, threshold reactions and -spectra were corrected for and different counting geometries normalized. Enrichment factors with reference to C1-chondrite are about 200 and 100 for lithophile refractory elements (e.g., V, Th, Hf and W) and rare earth elements (REE), respectively. Deficiencies were observed for Co, Cr, Mg and Na, etc. The C1-chondrite normalized REE patterns are close to those of extraterrestrial materials, with no anomaly of Eu, indicating an extraterrestrial origin of the grain samples analyzed.
Authors:G. Arana, U. Wätjen, C. Ingelbrecht, and P. Robouch
Five copper alloys were prepared with modern powder metallurgical processes in the frame of the European project Improvement of Means of Measurement on Archaeological Copper-Alloys for Characterisation and Conservation (IMMACO) and certified for As, Pb, Sn and Zn mass fractions. Similar in their composition to archaeological bronze alloys, these Certified Reference Materials (CRMs) are to be used for calibration of XRF instruments for characterization of archaeological samples either in the laboratory or in the field. This paper presents and compares the successful contribution of our non-destructive analytical methods (k0-NAA and PIXE) to the IMMACO project and to the certification of the five reference materials.
Background soils from areas around the United States Department of Energy facilities in Oak Ridge, Tennessee were characterized as part of an environmental restoration project. The data obtained in this project were validated using guidelines from the Environmental Protection Agency (EPA) Contract Laboratory Program (CLP), when EPA methods were used. However, there are no final EPA guidelines for validation of data obtained using radiochemical analytical methods, so procedures for validation had to be developed. This paper will describe the validation guidelines that were developed for neutron activation analysis (NAA) data and discuss the regulatory basis for them.
Authors:S. R. Kayasth, K. K. Swain, and T. Mukherjee
simple pre-irradiation separation approach has been worked out for the
determination of traces of tellurium in high purity selenium followed by
neutron activation analysis (NAA) for the end determination of the analyte/s.
The difference in volatilities of these elements has been utilized for the
separation of the analyte from the matrix. The complete volatility of selenium
at ~600 °C was established using neutron activation analysis and selenium
radiotracer. Standard addition was used to validate the results. The proposed
method of separation of selenium prior to irradiation could make the
determination of tellurium possible and also improved the detection limit by
Mn-nodule is one of the most important deep sea mineral resources to be explored and exploited in the next century. Analytical quality control based on this kind of Certified Reference Materials (CRMs) is therefore necessay. In the present work, nearly 30 elements in two Chinese Mn nodule Reference Materials (RMs), GSPN-2 and GSPN-3, were determined using extendedK0-relative comparison NAA technique, developed in our laboratory. The unique features of this work include; (1) high accuracy obtained by the interal validation function of our technique; (2) extensive determinable elements obtained by the hybrid nature of our software and (3) neutron flux self-shielding corrections.