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Abstract  

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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Abstract  

A simple procedure for the determination of90Sr in environmental samples is described. The method uses the different solubilities of the oxalates of calcium and strontium in presence of a large excess of calcium. For this reason the method is especially suited for Ca-rich samples, as e.g., bones or soils. However, after addition of supplementary calcium it works equally well for other types of samples. The method was tested by analyzing the IAEA Certified Reference Materials soil, animal bone and algae.

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Abstract  

For air pollution monitoring, about 1300 airborne particulate matter samples were collected by using a low volume air sampler and a polycarbonate filter at two sampling sites in an urban region, Daejeon, the middle of Korea from 2003 to 2006. Mass concentrations of the black carbon were measured using a smoke stain reflectometer. The concentrations of 24 elements in the collected samples were analyzed by using instrumental neutron activation analysis, and its temporal trends and enrichment factors were investigated under different environmental conditions. Analytical control was carried out by using certified reference materials.

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Abstract  

A Ni-Cr alloy was chosen as an in-house reference material for neutron flux measurement due to the well-known physical constants of the nuclides or interest and its low cost. The quantification of the Cr and Ni content was performed by neutron activation analysis (NAA), using certified reference materials from NIST as comparators. The concertrations and standard combined uncertainties were 19.32 ± 0.07 % for Cr and 80.2 ± 1.1 % for Ni, and the material is very homogeneous for Cr and moderate homogeneous for Ni.

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Abstract  

The knowledge of the chemical forms of metals is used to assess their availability and uptake by plants, and in sediments the forms of metals determine their transport and mobility in the aquatic media. This information may be obtained by determining chemical forms of metals (speciation) or different phases in which the metals are bound, obtained by applying extraction schemes. The analytical methods used include different steps and all of them must be validated. We report here the recommendations to minimize the errors in this kind of analysis. For validation the use of Certified Reference Materials (CRMs) and the participation in interlaboratory exercises are highly recommended.

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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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Abstract  

A new method is presented for the determination of Au and Pt in biological materials based on neutron activation analysis with radiochemical separation of gold. Separation of gold by electrolytic deposition on a niobium cathode ascertains the highest radiochemical purity without any interference from calcium or other major elements. With199Au as indicator for platinum the gold content of the sample not only strongly affects the limit of detection, but also causes interference by double neutron capture. Replicate analyses of BCR Certified Reference Materials No. 184, 185 and 186 were carried out.

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Abstract  

Levels of essential and toxic trace elements in six marine species greatly in demand in the international market (canned pink clams, razor clams, clams, king crab, sardines, and frozen albacore tuna fish) were studied. A special laboratory adequately equipped for handling and preparing biological materials, is described. The elements As, Br, Na, Se, Hg, Cr, Fe, Zn and Rb were determined by INAA, while copper and cadmium content were determined using RNAA. Significant differences were found on comparing the contents of some toxic elements in mollusk and other samples of marine food. Various certified reference materials (CRMs) of the IAEA, NIST and NIES were analyzed for quality assurance purposes.

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Abstract  

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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Abstract  

Recently developed radiochemical separation scheme for the simultaneous detemination of trace amounts of molybdenum and uranium in biological materials by NAA has been further refined and used for the detemination of these elements in several certified reference materials. The method assures very selective and quantitative separation of the indicator radionuclides:99Mo-99mTc and239Np from practically all accompanying activities followed by almost interference-free measurement by gamma ray spectrometry. The method can be applied to materials of both animal and plant origin and enables correcting the molybdenum results for uranium fission interference reaction thus assuring good accuracy for both elements down to ppb levels. The detection limits amount to 2.5 ppb (Mo) and 0.15 ppb (U) for ca. 200 mg samples.

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