Multielement analysis of concrete from nuclear reactors by INAA,ICP-MS and ICP-AES

There is a need to know, before dismantling nuclear plants, how the induced radioactivity is distributed in concrete. Computer codes are used to predict such a distribution, by applying input data like, among others, the chemical composition of the material. Biological shield concretes with particularly high boron or barium concentrations had to be analyzed. Instrumental neutron activation analysis is not able to determine all elements, thus, additional techniques are required, like ICP-MS and ICP-AES. The respective performances of these techniques are discussed. For INAA, the thermal neutron self-shielding was empirically corrected by using comparisons between thermal neutron activation (TNAA), epithermal and fast neutron activation (ENAA), ICP-AES and ICP-MS measurements.     

A comparison of INAA and ICP-MS/ICP-AES methods for the analysis of meteorite samples

Instrumental neutron activation analysis (INAA), inductively coupled plasma atomic emission spectrometry (ICP-AES) and ICP mass spectrometry (ICP-MS) (hereafter, ICPs) were applied to meteorite samples for the determination of elemental content. The analytical applicability and suitability of the three methods have been compared. Those comparisons led to the refinement of our analytical procedures for INAA and ICPs, yielding more reliable data. Our INAA data proved to be reliable enough for classifying meteorites, while the ICPs, especially ICP-MS, can characterize elemental abundance features in detail, as demonstrated by REE abundance patterns for the Allende meteorite. In this manner, INAA and ICPs can be used in a complementary fashion in cosmochemical studies.     

Multielemental automated INAA system for gold ore samples

A methodological approach to the activation analysis of bulk samples up to 300 g mass on a reactor is proposed. As applied to the analysis of massive gold-bearing ore samples, the questions of representativity of the samples with inhomogeneous distribution of the component under examination, specific effects caused by gold particles as well as large sample dimensions and mass are studied and ways for taking into account their influence are suggested. An automated system of multielemental neutron activation analysis of large samples of gold-bearing ores has been developed. The system has found application in geological prospecting and the mining industry.     

Multielemental analysis of soil samples by fast-neutron activation

Neutron activation analysis (NAA) have been used for the determination of major, minor, and trace elements in 20 soil samples from 5 crop fields of the Crop Research Centre, Pantnagar, India. Fast neutron activation analysis (FNAA) and cyclic neutron activation analysis (CNAA) have been used to determine the concentrations of various elements. The results for minor and trace elements are compared with the level of abundances of world soils. The present study provides the basic data of elemental concentrations in soil samples of 5 major crop fields located in one of the leading agricultural universities of India for future measurements with the objectives of efficient use of fertilizers and pesticides in accordance with the high yield.     

Multielemental NAA of geological micro-grain samples for origin identification

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.     

Multielemental analysis of metallurgical samples by thermal neutron activation

Instrumental neutron activation analysis (INAA) was applied to investigated a total of 16 samples of raw materials, intermediate and final products involved in metallurgical processes in Romanian Iron and Stell works Sidex Galatzy: iron ores and pellets from different regions of the world, cast iron, slag and steels. A series of chemical elements was determined in the analyzed samples: Al, As, Ce, Co, Cr, Fe, La, Mn, Na, Sc, Sm, V, W. A qualitative discussion regarding the passing of from elements with different chemical affinity for oxygen compared to that of iron, from the raw materials to slag or to finite products is presented.     

Multielemental Analysis of Yew,Pine and Spruce Needles by ICP-AES

Abstract

Concentrations of 22 trace and nutritional elements in yew, pine and spruce needles collected from urban and industrial areas were determined by inductively coupled plasma atomic emission spectrometry. Dependence of concentrations of trace elements in conifers species on sampling site was investigated. Various procedures of sample digestion (different acids, conventional hot plate and microwave digestion methods, dry ashing) were examined and discussed.     

Multielemental analysis of Mn-Fe nodules by ICP-MS: optimisation of analytical method

Two acid digestion procedures (microwave-assisted and room temperature) were developed for the quantitative analysis of ferromanganese nodules by inductively coupled plasma double focusing sector field mass spectrometry (ICP-SFMS). Different compositions of the acid mixture, dilution factors and corrections for spectral interferences were tested. A combination of nitric, hydrochloric and hydrofluoric acids is necessary for complete sample digestion, with lowest acid to sample ratios (v/m) of 15 and 1.5, respectively, for the last two acids. Sample dilution factors higher than 2 x 10(4) should be used in order to decrease matrix effects and provide robust long-term instrumental operation. In spite of high dilution, method detection limits in the sub-microg g(-1) range were obtained for 54 out of 71 elements tested, due to the high detection capability of ICP-SFMS, as well as the special care taken to ensure the purity of reagents, to clean the instrument sample introduction system and to minimise sample handling. Owing to the presence of unresolved (at the resolution available) spectral interferences, accurate determination of Au, Hg, Os, Pd, Re and Rh is impossible without matrix separation. The accuracy of the entire analytical method was tested by the analysis of two nodule reference materials. The results generated agreed to within +/-2% for about 10, within +/-10% for more than 40 and within +/-20% for about 50 of 53 elements for which certified, recommended or literature values are available. A precision better than 3%, expressed as the between-digestion relative standard deviation (n = 4), was obtained for the majority of elements, except in cases limited by low analyte concentrations.     

Characterization of Maya pottery by INAA and ICP-MS

A total of 81 pottery and 25 clay samples from the archaeological site and hinterland areas of Blue Creek in northwest Belize were analyzed by instrumental neutron activation analysis and inductively-coupled-plasma mass-spectrometry at the University of Missouri Research Reactor. Data generated for this study offers insight into local clay-resource variability and movement of pottery in the transition from Early (A.D. 250–600) to Late Classic (A.D. 600–850) occupation. Comparison of data generated by the two analytical techniques demonstrates the relative strengths and weaknesses of each method. This revised version was published online in July 2006 with corrections to the Cover Date.     

Multielemental Analysis of Agroindustrial By-Products Employed in Animal Feeding by INAA

Instrumental neutron activation analysis (INAA) with gamma-ray spectrometry was applied to determine As, Ca, Cd, Cl, Co, Cu, Cr, Fe, Hg, K, Mg, Mn, Mo, Na, Sb, Se and Zn in the Brazilian agroindustrial by-products. These materials are widely used in ruminant feeding. The results obtained were compared with requirement and maximum tolerable concentrations. The general conclusions from the data obtained were: (1) many by-products presented concentrations of some essential elements lower than the requirement concentrations, while in some concentrations of Cr, Fe, Mg and Se exceeded by a little the maximum tolerable concentrations, (2) the elements As, Cd, Hg and Sb, generally considered toxic, showed concentrations lower than maximum tolerable values.     

Multielemental analysis of Brazilian milk powder and bread samples by neutron activation

The concentrations of Na, Cl, Mn, Br, Fe, Zn, Rb, Sb, Sc, Cr, Al and Mg were determined in some types of bread and in some brands of milk powder consumed in the city of São Paulo (SP—Brasil), by instrumental neutron activation analysis. Radiochemical separations were carried out by means of retention of²⁴Na on hydrated antimony pentoxide (HAP) from a 8N HCl solution, after digestion of the organic matter. It was possible in this way to determine the radioisotopes⁶⁴Cu,^69mZn and¹⁴⁰La in the effluent solution. The detection limits of the trace elements analyzed in bread and milk powder samples were determined using the Currie and Girardi criterions.From a dissertation submitted by V. A. MAIHARA to the University of São Paulo in partial fullfillment of the requirements for a Master of Science Degree in Nuclear Technology.     

Computer graphics for quality control in the INAA of geological samples

A data reduction system for the routine instrumental activation analysis of samples is described, with particular emphasis on interactive graphics capabilities for evaluating analytical quality. Graphics procedures have been developed to interactively control the analysis of selected photopeaks during spectral analysis, and to evaluate detector performance during a given counting cycle. Graphics algorithms are also used to compare the data on reference samples with accepted values, to prepare quality control charts to evaluate long term precision and to search for systematic variations in data on reference samples as a function of time.     

Elemental analysis of vegetation samples by INAA internal standard method

Journal of Radioanalytical and Nuclear Chemistry - The application of comparator instrumental neutron activation analysis (INAA) combined with the internal standard method (ISM) was considered to...     

Multielement analytical procedure coupling INAA, ICP-MS and ICP-AES: Application to the determination of major and trace elements in sediment samples of the Bouregreg river (Morocco)

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.     

Arsenic speciation: HPLC followed by ICP-MS or INAA

Sensitivities for the measurement of four arsenic species, As^III, As^V, monomethylarsonic acid (MMA) and dimethylarsinic acid (DMA), in environmental waters and rice extracts by a new neutron activation analysis (NAA) method using pre-separation of the species by liquid chromatography were determined. A manual fraction collection was used to isolate the species, followed by instrumental neutron activation analysis procedures. The sensitivities determined for arsenic species in the samples varied from 1.21 to 1.47 ng per vial or about 30 μg·L⁻¹ in sample solutions which translates to about 900 ng arsenic per gram of rice for our HPLC-NAA experiments.     

Sample introduction systems for the analysis of liquid microsamples by ICP-AES and ICP-MS

There are many fields in which the available sample volume is the limiting factor for an elemental analysis. Over the last ten years, sample introduction systems used in plasma spectrometry (i.e., Inductively Coupled Plasma Atomic Emission Spectrometry, ICP-AES, and Mass Spectrometry, ICP-MS) have evolved in order to expand the field of applicability of these techniques to the analysis of micro- and nanosamples. A full understanding of the basic processes occurring throughout the sample introduction system is absolutely necessary to improve analytical performance. The first part of the present review deals with fundamental studies concerning the different phenomena taking place from aerosol production to analyte excitation/ionization when the liquid consumption rate does not exceed 100 μl/min. Existing sample introduction systems are currently far from the ideal and a significant effort has been made to develop new and efficient devices. Different approaches for continuously introducing small sample volumes (i.e., microsamples) have been reviewed and compared in the present work. Finally, applications as well as basic guidelines to select the best sample introduction system according to the sample particularities are given at the end of this review.     

Determination of rare earth elements in rice by INAA and ICP-MS

In order to improve the accuracy of reactor neutron activation analysis, flux gradients and spectrum changes in the irradiation capsule have been studied at the Kyoto University Reactor (KUR). The flux and spectrum monitoring samples of Fe, Co, Au, Sb, U and Ni were placed at several positions in a polyethylene irradiation capsule of 24 mm inner diameter and 98 mm length, and were irradiated in a pneumatic irradiation facility (Pn-2). The flux gradients were found to be rather negligible in the vertical (axial) direction while they were considerable in the radial one. The flux gradient was around 5%/cm for thermal neutrons and 10%/cm for epithermal and fast neutrons. The spectrum changes were dependent on the materials (polyethylene and silica) filled in the capsule. Based on these observations, the effect of the flux gradients and spectrum changes on the accuracy of reactor neutron activation analysis was discussed.     

INAA of Zr,La, Ce and Nd in geological samples in the presence of different uranium concentratios

Rock samples which contain relatively high concentrations of uranium may create problems of interference produced by fission products, when instrumental neutron activation analysis is used. The isotopes⁹⁵Zr,¹⁴⁰La,¹⁴¹Ce, 143Ce and 147Nd, which are commonly used in the neutron activation analysis of the corresponding elements, are also produced as fission products of²³⁵U. For each of these radioisotopes, a contribution factor is calculated theoretically and meaured experimentally using geological samples with different uranium contents.     

微波消解ICP-MS快速测定生物样品中的多种元素

建立了微波辅助HNO3消解样品,ICP-MS快速测定生物样品中Ti、Cr、Mn、Fe、Co、Ni、Cu、Zn、Ge、As、Se、Sr、Mo、Ag、Cd、I、Ba、Hg、Tl、Pb、Bi共21种微量及痕量元素。通过在线加入内标来校正基体效应和信号漂移对测量所造成的影响。各元素线性相关系数在0.9990以上,RSD小于6.0%。用本方法对国家标准样品GBW07601a(头发),GBW10010(大米),GBW10016(茶叶),GBW10023(紫菜)进行分析,结果满意。方法能满足生物样品痕量分析的要求。     

A comparison of N-type semi-planar and coaxial INAA detectors for 33 geochemical reference samples

While INAA is becoming a less popular analytical technique and it is a mature tool, there are still many improvement happening in the field. The effect of the new semi-planar detector is evaluated as compared to geological reference material and as its performance to the classical coaxial detector. The semi-planar detector offers improved accuracy (about 5%) for many analytes (As, Ba, Ce, Co, Cr, Eu, Hf, Lu, Nd, Rb, Sm, Th, U, Yb and Zn) while the coaxial gives an accuracy in the range of 10-15%.