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Summary  

Neutron activation analysis technique, using Au as flux monitor, was applied to determine element concentrations of Ca, K, Na, Mg, Mn and Sr in certified reference material (NIST 1400 Bone Ash). The results were compared with those using comparative INAA and they were compatible. The same results were obtained using the recommended k 0 factors, in order to obtain the activation cross section as input in concentration for the same reference material. Some applications in the health area aiming clinical evaluation in bone samples of medium and small-sized animals were performed and the viability of using this methodology was discussed.

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The k 0-method in INAA has been used at CENA/USP Brazil for analyzing geological and biological materials. With the acquisition of a well-type detector, it was realized that the true-coincidence effects, originally corrected by semi-empirical procedures with the in-house k 0-software (Quantu-INAA), would affect the accuracy of results. Thus, new coincidence correction algorithms were developed, based on a theoretical equation for obtaining the correction factors. Validation of the algorithms was performed by analysis of plant certified reference materials.

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The analysis of impurities in uranium matrices is performed in a variety of fields, e.g., for quality control in the production stream converting uranium ores to fuels, as element signatures in nuclear forensics and safeguards, and for non-proliferation control. We have investigated the capabilities of time-of-flight ICP-MS for the analysis of impurities in uranium matrices using a matrix-matched method. The method was applied to the New Brunswick Laboratory CRM 124(1–7) series. For the seven certified reference materials, an overall precision and accuracy of approximately 5% and 14%, respectively, were obtained for 18 analyzed elements.

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The paper presents the results of radiological investigation of several mushroom samples collected in the fall of 2004 in different parts of Europe. The work was performed in order to support decision making to develop and produce a certified reference material for quality assurance of radionuclide measurements in environmental samples. The levels of 137Cs in mushrooms varied widely ranging from 0.6 to 4300 Bq/kg on dry mass basis, while those of natural 40K were relatively constant. In one sample 60Co of unknown origin was detected (25±2 Bq/kg dry mass), while 90Sr concentrations were usually below the detection limit (<150 mBq/kg dry mass).

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In this study a protocol for blood serum analysis was defined and the concentrations for Br, Ca, Cl, Fe, Na, Rb, Se and Zn were obtained by instrumental neutron activation analysis. Blood samples were collected from healthy elderly volunteers who were selected based on the SENIEUR protocol. Contamination of blood by the collection procedure was also evaluated and found negligible. The serum was separated by centrifugation, then freeze-dried and analyzed. Most of results obtained were within the acceptable value ranges used by physicians for normal population. The certified reference material, NIST SRM 1566b Oyster Tissue was analyzed for quality control.

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The advantages and drawbacks of using instrumental neutron activation analysis (INAA) and inductively coupled plasma mass spectrometry (ICP-MS) for soil, sediment, plant and water pollution studies are discussed. The experimental procedures used for each method and for each type of sample matrix are described. They were tested on several certified reference materials. The results obtained on these materials showed good agreement for many elements for which the two techniques are suited, and they were complementary for the other elements which are also of environmental interest. An element-by-element assessment is presented to indicate the precautions to be taken and the most convenient technique for each of them.

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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 extendedK 0-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.

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Prompt gamma activation analysis using a focused thermal neutron guided beam at JAEA JRR-3M was applied to the determination of B in ceramic certified reference materials (BAM CRM S-003 Silicon Carbide Powder and NMIJ CRM 8004-a Silicon Nitride Powder). Cl and Si were used as internal standards to obtain linear calibration curves of B. The analytical result of B in BAM CRM S-003 was in good agreement with the certified value. The relative expanded measurement uncertainties (k = 2) were 4.8% for BAM CRM S-003 and 4.9% for NMIJ CRM 8004-a.

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A method has been developed for the analysis of rare earth elements (REEs) in kimberlite samples using inductively coupled plasma mass spectrometer (ICP-MS). The samples were dissolved using sodium peroxide fusion and after appropriate dilutions the solutions were analyzed using ICP-MS. The paper presents the concentration of rare-earth elements as determined by ICP-MS in eight kimberlite samples from Central India. The method was validated using certified reference materials STSD-1 and STSD-2 from Canadian Certified Reference Material Project. The method detection limit of various REEs varies from 0.12 to 1.54 mg kg−1. The total REE concentrations range from 418 to 726 mg kg−1 and fall within the interval of those reported in the literature for kimberlites. Despite the marked difference in the REE contents, all the analyzed samples show similar REE patterns that resemble those for kimberlites. In order to compare ICP-MS results, the samples were analyzed using instrumental neutron activation analysis which is a reference method for determination of REEs in geological samples.

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Simple and rapid analytical procedures for the AAS (Atomic Absorption Spectrometry) determination of Zn, Cd, Ni, Mo and Pb in biological, geological and soil samples are described. Special attention was paid to sample preparation, which is the step, most vulnerable to contaminants. Optimal conditions are presented for the wet digestion of plant matrices, products and waste for the coal treatment and soil matrices with different acids including: nitric, perchloric, hydrochloric, hydrofluoric, sulfuric and hydrogen peroxide along with optimal temperature programmes for subsequent electrothermal (ET)-AAS and flame (F)-AAS determination of Zn, Cd, Ni, Mo and Pb. Results of the analysis of all samples are discussed. The proposed method allows obviating the organic matrix (soil and plant) destruction stage, shortening the analyte dissolution time, reducing cost, and minimizing hazards of loss and contamination. The validity and versatility of the methods developed were verified by the analysis of certified reference materials.

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