Radioanalytical methods for the non-destructive analysis of lunar samples

The elemental compositions of Apollo 11 and Apollo 12 lunar soil samples 10084,141 and 12070,83 and Apollo 12 rock fragment 12063,73 were determined by non-destructive radioanalytical methods. Main mineral fractions and glasses separated from these samples were analyzed as well. Instrumental neutron activation analysis (INAA) was used to determine Na, Mg, Al, Si, K, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Zr, Cs, Ba La, Ce, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Tm, Yb, Lu, Hf, Ta, W, Ir, Au, Th and U. A method of delayed neutron counting was used for the determination of uranium, and non-dispersive radioisotopic X-ray fluorescence analysis was applied to the determination of Ti, Fe, Sr, Y and Zr.     

Determination of Elements in Japanese Standard Soil Materials by Means of Insturmental Neutron Activation Analysis

Instrumental neutron activation analysis (INAA), and inductively coupled plasma mass spectroscopy (ICP-MS) were applied to the determination of major elements and rare earth elements in Japanese Standard Soil Materials (NDG-1 to -8). Eight major elements, Al, Fe, Ti, Ca, Mg, Mn, K, and Na were determined by INAA. A comparison of the data for rare earth elements obtained by INAA and ICP-MS shows that the data of the contents determined by the two different analytical methods are in fairly good agreement with each other.     

Use of INAA,PGAA, and RNAA to determine 30 elements for certification of an SRM: Tomato Leaves, 157a

Analyses for certification have been made for the determination of 30 elements in the National Institute of Standards and Technology (NIST) Tomato Leaves renewal reference material, SRM 1573a. Three of the analytical techniques used were instrumental neutron activation analysis (INAA), radiochemical neutron activation analysis (RNAA), and prompt gamma activation analysis (PGAA). These techniques provided data on 19 elements by INAA, 10 elements by PGAA, and 7 elements by RNAA, with some overlap between techniques. For example, INAA was able to obtain overall analytical uncerainties (at the 95% confidence level) averaging ±2.2% for major and minor constituents (Ca, Mg, K), ±3.3% for constituents from 1 to 1000 g/g (Na, Fe, Al, Mn, Ba, Zn, Rb, La, Cr), and ±6.4% for elements between 10 and 1000 ng/g (Co, V, Se, Th, Sc, Sb), using sample dry weights of approximately 150 mg. These analyses represent the most extensive use to date of nuclear analytical techniques in the certification of a trace element SRM at NIST.     

Determination of trace elements in atmospheric wet precipitation by instrumental neutron activation analysis

Instrumental neutron activation analysis (INAA) methods have been developed for the simultaneous determination of multielement concentrations in both particulate and soluble fractions of atmospheric wet precipitation (AWP). Samples of AWP collected across Canada by Canadian Network for Sampling Precipitation (CANSAP) have been analyzed. The INAA method involves four sequential irradiations and counting after five different decay periods for measuring Ag, Al, As, Au, Ba, Br, Ca, Ce, Cl, Co, Cr, Cu, Dy, Fe, Hf, Hg, I, K, La, Mg, Mn, Na, Rb, Sb, Sc, Se, Sm, Sr, Ti V and Zn. Precision and accuracy of the INAA methods have been evaluated, and detection limits have been calculated.     

Quality Control in Element Analysis of Plant Materials

A worldwide laboratory intercomparison was organized by the International Atomic Energy Agency's Analytical Quality Control Services (AQCS) involving the determination of elements in plant materials used for human consumption. The main purpose of this work was to evaluate the performance of our analytical methods including sample preparation and to obtain new reference materials that can be used in our further work. Both materials (spinach and cabbage) were analyzed by inductively coupled plasma atomic emission spectrometry (ICP-AES) and instrumental neutron activation analysis (INAA). Six subsamples of each material were subjected to our digestion procedure and the solutions were measured by ICP-AES. The dried samples were analyzed using INAA. Up to 26 elements were determined in plant materials. For easy review of our data a score has been calculated based on the reference value for each measured element. According to our results the ICP-AES technique was useful for determination of the following elements: Ba, Ca, Cr, Fe, K, Mn, Mo, P, S, Sr, Ti. The INAA method was reliable for measurement of Ce, Co, Mn, Na, Rb, Th, and V.     

Elemental characterization of the new Czech meteorite ‘Morávka’ by neutron and photon activation analysis

Forty two major, minor and some trace elements were determined by activation analysis in the new Czech Morávka H5 chondrite, which fell on May 6, 2000 in the vicinity of Morávka, north-east Moravia. The elements Na, Mg, Al, Si, Cl, Ca, Ti, V, Mn, Co, Ni, and Cu were determined by means of instrumental short-time neutron activation analysis (INAA), whereas another group of elements, namely Sc, Cr, Fe, Co, Ni, Zn, As, Se, Br, Sb, La, Sm, Ir, Au and Hg were assayed using long-time INAA. Most of the rare earth elements (REE) were determined by radiochemical neutron activation analysis (RNAA) using precipitation of their oxalates, whilst for the determination of Rb and Cs an RNAA procedure based on selective sorption of the elements on ammonium phosphomolybdenate was employed. Mg, Ca, Ti, Mn, Ni, Sr, Y and Zr were determined by instrumental photon neutron activation analysis (IPAA) using the irradiation with 20 MeV bremsstrahlung from a microtron. For quality control, the U.S. Geological Survey (USGS) reference rocks basalt BCR-1 and diabase W-1 were analyzed. Moreover, the self-verification principle in activation analysis was employed to increase the credibility of the obtained results.     

Evaluation of concentrations of major and trace elements in human lung using INAA and PIXE

The elemental concentrations of Br, Ca, Ce, Cl, Co, Cr, Cs, F, Fe, Hf, K, Mg, Mn, Na, O, Rb, Sb, Sc, Se, V and Zn in 15 human lung autopsy samples, taken from subjects aged more than fifty years old, were determined by instrumental neutron activation analysis (INAA) using reactor neutrons in conjunction with a high resolution detection system. Two modes of irradiation and counting were applied; namely cyclic neutron activation analysis (CNAA) and conventional neutron activation analysis. Proton induced X-ray emission (PIXE) analysis, using a proton beam emerging from a 2 MV Van de Graff accelerator, was additionally employed and Ge, Ni, P and Ti were also identified in the lung tissue. Detection of the X-ray spectra was performed using a high resolution Si(Li) semiconductor. The relevance of these results, including a comparison between the concentrations of elements measured in a pig's lung using CNAA and those found in the human lung is discussed.     

An ENAA and PGAA comparative study of anoxic Black Sea sediments

A comparative study performed by means of both epithermal neutron activation analysis (ENAA) and prompt gamma neutron activation analysis (PGAA) concerning the distribution of 9 elements (Na, Al, Cl, K, Ca, Ti, Mn Fe and Sm) in unconsolidated sediments collected from the Black Sea anoxic region is presented. Principal component analysis (PCA) was used as a supplementary method in interpreting experimental data. The final results have shown that eight of them (Na, Al, Cl, K, Ti, Mn, Fe and Sm) have concentrations which differ by less than 30% from the corresponding concentrations of Upper Continental Crust (UCC), confirming the continental origin of sediments. At the same time, Ca concentration was about six times higher than that of UCC, this significant enrichment being due to the presence of the neighbouring oxygenated zone of considerable deposits of shell debris, characteristic of the Western Black Sea Continental Platform. Excepting Na and Mn, the concentrations of all other elements involved in this intercomparison were coincident within one standard deviation which attests the accuracy of this test. At the same time, PCA revealed the presence of five clusters, which could be put into concordance with the mineralogical composition of sediments, each of them consisting in equal proportions of elements determined by both methods.     

Comparative PGAA and NAA results of geological samples and standards

Concentrations of major and trace elements in volcanic rock and soil samples, including geological standard reference materials, were determined by neutron activation analysis (NAA) and prompt gamma activation analysis (PGAA), both using the k ₀-standardization method. The paper highlights the different experimental procedures, such as sample preparation, data collection and spectrum evaluation. In geological samples, PGAA gives precise results for major elements (Si, Ti, Al, Fe, Mn, Mg, Ca, Na, K and—as a unique method—for H), for some of the light trace elements as B and Cl, as well as for Sc, S, Cr, Co, Ni, Cd, Nd, Sm and Gd. NAA is sensitive for the rare earth elements, and for many major (Ti, Al, Fe, Mn, Mg, Ca, Na, K) and trace elements (e.g.: Sc, V, Cr, Co, Ni, Cu, Zn, As, Se, Rb, Sr, Zr, As, Sb, Ce, Ba, Hf, Ta, W). For most major elements the results obtained by the two methods show good agreement. The comparison of the results obtained for trace elements is not always possible, since PGAA is less sensitive and concentrations are often below its detection limits. Nevertheless, the complementarity of NAA and PGAA allows nearly panoramic analysis of geological materials.     

Use of neutron activation analysis for the characterization of single-wall carbon nanotube materials

Instrumental neutron activation analysis (INAA) and prompt gamma neutron activation analysis (PGAA) were used to characterize a variety of single-wall carbon nanotube (SWCNT) materials from different principal production processes, as well as a material containing SWCNTs together with other carbon species, catalyst residues, and trace element contaminants to be issued by the National Institute of Standards and Technology for characterization and distribution as Standard Reference Material SRM 2483 Carbon Nanotube Soot. INAA proved to be well suited for the direct determination of catalyst and contaminant trace elements requiring only minimal sample preparation. PGAA complemented the INAA data in particular with determinations of the light elements. Carbon and hydrogen results provided information on the materials purity and storage properties. Strategies for the quality assurance of the measurements in these new materials were developed. INAA and PGAA data were provided for the value assignment of mass fractions of catalyst and trace elements in the candidate SRM and a systematic overview was obtained of the catalyst and trace element contaminants associated with each of the major production routes.     

Combinatorial study of thin film metal hydride by prompt gamma activation analysis

Cold neutron prompt gamma activation analysis (PGAA) was used to determine the mass of hydrogen in Mg hydride thin films with varying hydrogenation times. The results suggest that hydrogenation of the Mg thin films remains unsaturated even after 48 h of treatment, contrary to the indications of inferential hydrogen measurement methods. To demonstrate PGAA as an effective combinatorial methodology for hydride thin films, a continuously varying composition gradient of thin Mg_yTi_(1−y) hydride film with y ranging from 0.65 to 0.94 was prepared and analyzed by both PGAA and instrumental neutron activation analysis (INAA). The variation in the molar ratio of Mg, Ti, and H was obtained for nine 5 mm wide segments of the film.     

Accelerated denitration by formic acid accompanied with residual acid-electrolytic trimming

The fruit bodies of wild-growing higher fungi (macromycetes), commonly called mushrooms, of various genera and species collected in localities with different geochemical features and man-made burden in the Czech Republic were analyzed by different modes of activation analysis. The elements Na, Mg, Al, S, Cl, K, Ti, V, Mn, Cu, Br, Ba and Dy were determined by short-term instrumental neutron activation analysis (INAA). Short-term epithermal INAA (ENAA) was used for determination of I and other elements, such as Rb, Ag, and U. The elements Na, K, Sc, Cr, Fe, Co, Cu, Zn, As, Se, Br, Rb, Ag, Cd, Sb, Cs, Ba, La, Ce, Sm, Eu, Hf, Au, Hg and Th were determined by long-term INAA, whereas long-term ENAA enabled determination of several other elements, such as Ni, Ta, W and U. The analytical possibilities of instrumental photon activation analysis (IPAA) using a microtron were also explored and found useful for determination of several additional elements, namely Sr, Y, Zr, Nb, and Pb. High concentrations of several essential and toxic trace elements found (up to hundreds of mg^.g^-1, dry mass) should be of concern in nutritional studies, because mushrooms form non-negligible part of diet in many countries, especially in Middle and East Europe.     

Improvements in food analysis by thermal neutron capture prompt gamma-ray spectrometry

Summary The thermal neutron prompt gamma-ray activation analysis (PGAA) facility, operated by the US Food and Drug Administration and National Institute of Standards and Technology Center for Neutron Research, has been redesigned to lower background radiation levels and improved analytical capabilities. Analysis of 22 element standards and food and botanical certified reference materials revealed significant sensitivity increases and lower limits of detection for H, B, C, N, Na, Al, P, S, Cl, K, Ca, Fe, and Cd. Mass fractions for these elements, as well as Mg, Al, Si, Ti, Mn, Fe, Cu, I, Zn, Sm, and Gd, were determined for 6 dietary supplements.     

Determination of 21 elements by INAA for certification of SRM 1570a,Spinach

Analyses for certification have been made by instrumental neutron activation analysis (INAA) for the determination of 21 elements in the National Institute of Standards and Technology (NIST) Spinach renewal reference material, SRM 1570a. Elements determined included ones with short halflife products (Al, V, Ca, Mg), intermediate halflife products (Mn, Na, K, La), and long halflife products (Ba, Co, Cr, Cs, Eu, Fe, Rb, Sb, Sc, Se, Sr, Th, and Zn). For the first time a new robotic sample changer was used in the counting of long halflife indicator isotopes for certification of an SRM. Uncertainties obtained averaged±1.80% for the four major and minor constituents (Ca, K, Mg, Na); ±3.14% for elements with concentrations from 1 to 400 mg/kg (Al, Ba, Cr, Fe, Mn, Rb, Sr, and Zn); and±8.31% for the ultra trace elements (<1 mg/kg) (Co, Cs, Eu, La, Sb, Sc, Se, Th, and V).     

Determination of trace elements in fish by instrumental neutron activation analysis

Instrumental neutron activation analysis, INAA, was utilized for the determination of Al, Au, Br, Ca, Cl, Co, Cr, Cu, Fe, I, K, Mg, Mn, Na, Rb, Sc, V and W in 12 Tilapia Nilotica samples collected from the Aswan High Dam Lake following the destructive techniques.     

Determination of elemental levels in medicinally important Indian leaves by instrumental neutron activation analysis

Levels of As, Ba, Br, Ca, Ce, Cl, Cr, Cs, Eu, Fe, Hg, I, K, La, Mg, Mn, Na, Ni, Rb, Sb, Sc, Sm, Sr, Th, Zn, and U have been determined in ten leaves widely used in ayurvedic medicine by instrumental neutron activation analysis (INAA). The neutron irradiations were performed with a 100 kW Triga nuclear reactor and the induced activity was counted with a gamma-ray spectrometer. Based on elemental levels obtained the utility of these leaves in medicine are discussed.     

Determination of trace elements of some Egyptian crops by instrumental neutron activation,inductively coupled plasma-atomic emission spectrometric and flameless atomic absorption spectrophotometric analysis

Instrumental neutron activation analysis was used for the determination of Al, Br, Ca, Ce, Cl, Co, Cr, Cs, Eu, Fe, K, La, Mg, Mn, Na, Rb, Sb, Sc, Se, Ti, Th, V and Zn, ICP-AES for the determination Al, Ag, Ba, Be, Ca, Co, Cr, Cu, Fe, Ga, K, Li, Mg, Mn, Na, Ni, P, Sc, Sr, Ti, V and Zn and flameless AAS for the determination of Cd, Hg and Pb in egg plant, potatoes, green pepper (Leguminosae), vegetable marrow (Cucurbitaceae), pears, apple (Rosaceae), castor oil plant (Euphorbiaceae), lettuce (compositae), dill, parsley, coriander (Umbelliferae), and in some soil samples collected from Aswan province.     

Uptakes of trace elements in Zn-deficient mice

A multitracer technique was used to obtain uptake rates of essential trace elements in various organs and tissues in Zn-deficient mice. A multitracer solution, containing more than 20 radioisotopes, was injected intraperitoneally into Zn-deficient state mice and control ones. Uptake rates of the radioisotopes were compared with concentrations of trace elements determined by instrumental neutron activation analysis (INAA) in order to study a specific metabolism of Zn and other essential trace elements, such as Mn, Co, Se, Rb, and Sr. The result suggests that Zn is supplied from bone to other organs and tissues and an increase in Co concentration in all organs and tissues depends on its chemical form, under the Z-deficient state.     

Instrumental neutron activation analysis of spruce needles and trees

Tree rings and needles of young spruce clones from the immission area of the Al-refinery Ranshofen (Upper Austria), which had ceased production in 1992, were investigated by INAA. Short time irradiation was performed for determining, Al, Mn, Ca and Cl, while the elements Na, K, Rb, Ba, Zn, Fe, Sc, Cr, Co, Br and in some samples also Ca were determined via middle- and long-lived radioisotopes. Irradiation and counting conditions are given. Accuracy and sensitivity are sufficient to describe the trends of the element concentrations in needles and with the exception of Cr, Sc and Br, in tree rings. Ca-concentrations derived from⁴⁹Ca (short-time irradiation) and⁴⁷Ca (long-time irradiation) are compared and show good agreement Additionally Mg was determined in some samples by ICP-AES and if possble, by INAA. The results are compared.     

Determination of uranium fission interference factors for INAA

Instrumental neutron activation analysis (INAA) is a very suitable technique for the determination of several elements in different kinds of matrices. However, when the sample contains high uranium concentration this method presents interference problems of uranium fission products. The same radioisotopes used in INAA are formed in uranium fission. Among these radioisotopes are ¹⁴¹Ce, ¹⁴³Ce, ¹⁴⁰La, ⁹⁹Mo, ¹⁴⁷Nd, ¹⁵³Sm and ⁹⁵Zr. The purpose of this study was to evaluate uranium fission interference factors to be used in the INAA of environmental and geological samples containing high levels of U. The obtained interference factors agreed with literature reported values. The results point to the viability of using these experimentally determined interference factors for the correction of uranium fission products.