Old stones, new science

Museum collections include many French medieval limestone sculptures of unknown origin. To localize the source of their stone, the composition of samples from such sculptures has been determined by neutron activation analysis (INAA). Using multivariate statistics, we compared their compositional profiles with groups of samples from French monuments and from quarries known to medieval craftsmen. This process has suggested a provenance for some sculptures and allowed us to assign others to a region or a quarry that provided stone for their production.     

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.     

The use of neutron activation in dietary reference material analysis

Summary Results for a number of trace elements in a total human diet material (USDIET-1), obtained by the application of both INAA and RNAA are presented. Several dietary reference materials such as NBS SRM 1577A, and BCR CRM Single Cell Protein were also analyzed, and these results are also given. Combining measurements on short and long lived radionuclides, the INAA approach is useful for the determination of about 20 elements. In order to expand the elemental coverage or improve detection limits, RNAA was also explored in two modes: separation of radionuclides using organic ion exchange resins and the use of hydrated manganese dioxide. This combination is applicable to 15 trace elements. For example, using RNAA, the following results were obtained for USDIET-1: Cd=31.8, Mo=280, Cr=71, Ag=4, As=117 and Sb=9.4 g/kg. In the INAA mode, special attention was given to Al, F and Se. The F content of USDIET-1 was found to be 840 mg/kg, a rather high value, resulting from handling USDIET-1 by Teflon tools. By applying INAA and RNAA under two different laboratory conditions, it has been demonstrated that, even for the so-called difficult to determine elements like Cr, As or Mo, consistent results can be obtained. Thus, NAA promises to be a strong tool for human nutritional studies.

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Einsatz der Neutronenaktivierung für Nahrungsmittel-Referenzmaterialien

     

On the reliability of trace metal analyses: Results of intercomparison analyses of a river sediment and an estuarine sediment

Summary The paper reports on two intercomparison analyses of 18 trace metals in a river sediment and an estuarine sediment. The results obtained by more than twenty working groups reveal clear methodological differences between the two most-used methods, namely, atomic absorption spectrometry (AAS) and instrumental neutron activation analysis (INAA): while the accuracy of the AAS measurements decreased on the average in the 2nd intercomparison analysis (estuarine sediment) in relation to the 1st intercomparison analysis (river sediment), the accuracy of the INAA values improved clearly. Accuracies of the trace metal determination in both sediments — expressed as the double standard deviation of laboratory means — were found between about ±20% and ±90% for the AAS method, and between ±10% and ±50% for the INAA measurements.

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Über die Zuverlässigkeit der Bestimmung von Spurenmetallen. Ergebnisse von Ringanalysen eines Fluß- und Ästuarsediments

Zusammenfassung Es wird über die Ergebnisse zweier Ringanalysen bezüglich 18 umweltrelevanter Spurenmetalle in einem Fluß- bzw. Ästuarsediment berichtet. Die Ergebnisse von mehr als 20 Arbeitsgruppen zeigen für die beiden am häufigsten eingesetzten Analysenmethoden Atomabsorptions-Spektrometrie (AAS) und instrumentelle Neutronenaktivierungsanalyse (INAA) deutliche methodenspezifische Unterschiede: Während sich die Richtigkeit der AAS-Messungen in der 2. Ringanalyse (Ästuarsediment) gegenüber der 1. Ringanalyse (Flußsediment) im Mittel verschlechterte, verbesserte sich die Richtigkeit der INAA-Werte deutlich. Die durchschnittlich erreichten Richtigkeiten bei der Spurenmetallbestimmung in den beiden Sedimenten — ausgedrückt durch die doppelten Standardabweichungen der Labormittelwerte — beträgt für die AAS-Messungen ca. ±20% bis ±90% und für die INAA-Messungen ca. ±10% bis ±50%.

     

Indirect determination of soluble trace elements in certified reference materials by neutron activation analysis

Since 1983 we have analyzedaqua regia extracts from environmental reference materials of 5 different soils and 4 different sludges by neutron activation analysis. Aqua regia as such is not accepted for irradiation in a nuclear reactor, and therefore the solution has to be evaporated to dryness, mixed and dried to constant weight before an aliquot can be taken and subjected to instrumental neutron activation analysis (INAA). Results for leachable Cr and Zn were found to display greater variability than results for total contents of these elements, and the reasons for this will be discussed.For the 1994 certification campaign for one soil and two sludges we have chosen to determine the total content of trace elements in these reference materials by INAA before and afteraqua regia leaching. The leachable contents are then found indirectly as a difference between the two results; in this way we eliminate the sources of uncertainty associated with the drying and handling of theaqua regia extracts, and we reduce the contributions from counting statistics.     

INAA and AAS of different products from sugar cane industry in Pakistan: Toxic trace elements for nutritional safety

Instrumental neutron activation analysis (INAA) have been used to determine As, Br, Hg, Sb and Se in combination with atomic absorption spectrometry (AAS) as a complementary technique for the quantification of Cd and Pb in jaggery, brown sugar, white sugar and molasses. All sugar cane products were collected from the local sugar cane industry of Pakistan. The highest concentration of these potentially toxic elements was quantified in molasses; however, molasses together with jaggery, brown sugar and white sugar contains trace amounts of all of these elements. Due to very low concentration of Cd it could only be detected in molasses. To evaluate the percentage contribution of these elements in the sugar cane products to the weekly recommended values, intakes on weekly consumption of 100 g of each item have also been calculated which follow the pattern Br>Se>Pb>Hg>As>Sb. The elevated Br contents may be attributed to the use of Br-containing chemicals for fumigation; however, these contents are well within the tolerance levels. The estimated weekly intake of all toxic elements is very low indicating that sugar cane products can be safely ingested as part of the diets.     

Diffusion of obsidian in the Mediterranean basin in the neolithic period: A trace element characterization of obsidian from Sardinia by instrumental neutron activation analysis

Obsidian samples from Monte Arci in Sardinia (Italy) have been characterized by their minor and trace element concentration in order to find discriminating parameters useful to provenance the prime matter of obsidian artifacts. Obsidian samples were collected both at the SA, SB and SC outcrops and far away from them. All samples were submitted to INAA. The trace element concentration appears to be very useful to discriminate the three flows. Multivariate statistical analysis confirms the satisfactory distinction between the three sources. The assignment of the samples collected far away from outcrops to a specific flow (SC) validates the hypothesis that obsidian blocks might have been washed out by alluvial events.     

Trace element characterization of medieval and post-medieval glass objects by means of INAA and EPMA

Instrumental neutron activation analysis (INAA) was applied to create a database for minor and trace elements in medieval and post-medieval glassware in order to establish a methodology for estimating the origin of the glass objects. First, general characterization of glass types was done on the basis of the results obtained by the use of electron probe microanalysis (EPMA). Information received by the use of INAA provided the additional valuable data reflecting to some extent the method of preparation or the differentiation of various sources of certain raw materials. Several glass samples and a set of various reference glass materials were used for our experiments.     

The feasibility of utilizing the64Cu annihilation 511 keV line in INAA

This work demonstrates that the⁶⁴Cu 511 keV line can be used in INAA to determine trace amounts of Cu in biological and environmental materials. The method to reduce the serious interference in γ-ray spectroscopy from nuclides having high energy γ-rays is discussed. A simple INAA procedure is proposed and examined for 7 different SRM materials. An accuracy and precision better than 3% are achieved for tested samples with Na-to-Cu content ratio less than 1000. The minimum detectable Cu concentrations of less than several ppm are calculated for all the analysed samples. To retain the multi-element capability, the k₀-and the modified monostandard methods are applied by using the⁶⁴Cu 511 keV line as the comparator. With the aid of the program MULTINAA, maximum 32 elements are simultaneously determined with an accuracy better than 5% for most elements.     

Gold-Silver Mineralization in Submarine Hydrothermal Sulphides: INAA Results After Ten Years of Intense Prospecting

During the last twenty years, IFREMER has organized many diving cruises to collect geological, mineralogical and geochemical data on submarine hydrothermal mineralization. Gold and chalcophile trace elements have been determined by instrumental neutron activation analysis (INAA) in Pierre Süe Laboratory. Particularly for gold and silver determination, but also for In, As, Sb, Se, INAA is the most sensitive instrumental procedure. Typically, the East-Pacific Rise (EPR) deposits are gold-poor compared with the Mid-Atlantic Ridge (MAR) and the Lau Basin deposits. Our INAA data plotted in a Au-Ag diagram support the difference between back-are basin mineralization and spreading oceanic ridges. The most interesting samples for gold prospecting have been discovered in the Logatchev hydrothermal field at 14°45 N on the Mid-Atlantic Ridge: they show an exceptionally high mean content of gold, about 9 ppm, with a maximum of 56 ppm for one sample which contains significant amounts of native gold and electrum. It is the first conclusive evidence of a primary gold-copper association in seafloor sulphides. This may be compared with fossil hydrothermal deposits from the Oman ophiolitic complex.     

Trace element characterization of ochre from geological sources

As evident from archaeological excavation, ochre was widely used for ceremonial, mortuary, and other purposes around the world. However, the ancient meaning and procurement practices of ochre are not well understood. This study examines the variation in the major, minor and trace element patterns of ochre from iron oxide sources in southeastern Missouri to better understand the differences that may occur within and between sources. Samples were analyzed by instrumental neutron activation analysis (INAA), X-ray fluorescence spectroscopy (XRF), and the data were interpreted by Pearson’s linear correlation and multivariate analysis. The data indicate geochemical trends in ochre that satisfy the provenance postulate.     

Primary standards in activation analysis

The availability of natural matrix reference materials evaluated for trace element content has resulted in their widespread use as standards (i.e., calibration materials; comparators) for instrumental neutron activation analysis (INAA). Due to the uncertainties associated with their certified values, the limited number available, and the relative matrix independence of INAA, these reference materials are more properly utilized as quality assessment materials, after calibration of the INAA analytical system with true primary standards. Terminology is defined, the use of matrix reference materials to evaluate the analytical system is discussed, techniques for the accurate preparation of primary standards for trace element analyses are reviewed, and necessary precautions in the accurate comparison of samples to standards are presented.     

A european intercomparison of vegetal standard reference materials,based on INAA and some non nuclear spectrochemical techniques

INAA results obtained on 11 vegetal samples proposed as European reference standards, in nutritional, agricultural and analytical studies are reported. A comparison is also reported with the data obtained by 38 European laboratories, by using spectrochemical methods (ICP atomic absorption, X-ray fluorescence, etc.). The usefulness of Instrumental Neutron Activation Analysis (INAA) is stressed, particularly when more usual methods are not sensitive enough for microelements that are important markers of toxic and pollutant substances. To this class belong lanthanides and other rare elements (Sc, Cs, Rb), which can be used both as fingerprint of soil provenance and for evaluating the homogeneity of the sample.     

Provenance and indirect dating study on Hongzhou Kiln porcelains by INAA

Over 100 sherds were collected from Hongzhou Kiln of Jiangxi Province, China and their body samples were analyzed by INAA. The compositional differences between samples with the same period but different provenance were observed. The contents of Na, Rb, Ba, Fe, Th, U, etc., were found to be different among samples from different periods, which implies they may be used to identify the manufacturing age indirectly. The analytical data were further processed by principal components analysis (PCA). The statistical results show that all the sherds can be classified into 5 groups: (1) Eastern Han and Eastern Wu; (2) Western Jin, Eastern Jin and Southern Dynasties; (3) Sui; (4) Early Tang and Middle Tang; (5) Late Tang and Five Dynasties.     

Trace element analysis of turkey vulture (Cathartes aura) feathers

Ten feather samples, including primary and secondary flight and tail feathers, were analysed for the trace element composition of vane and rachis structures using instrumental neutron activation analysis (INAA), inductively coupled plasma-mass spectrometry (ICP-MS), and cold vapour atomic absorption spectroscopy (CVAAS). Five environmentally significant elements, Cr, As, Se, Sb and Hg, were analysed by INAA and ICP-MS/CVAAS. A further seventeen elements were analysed by ICP-MS. The majority data obtained by INAA and ICP-MS/CVAAS were not statistically significantly different (p = 0.05), although the removal of isobaric interferences using dynamic reaction cell technology was essential to produce ICP-MS data that were consistent with INAA for Cr, As and Se. Significantly higher trace element concentrations were observed for vane relative to rachis for all elements, except Cu and Hg. These elements displayed vane/rachis ratios of 0.7 ± 0.2 and 1.0 ± 0.2, respectively. In general, vane and rachis subgroups afforded data that were consistent with a normal distribution, with RSDs in the range (12–83) % for INAA analyses. A total of 18 outliers were noted amongst the various feather, structure, element combinations, with 14 outliers being observed in the vane and/or rachis structures of the same tail feather. Given the significant differences in vane and rachis concentrations observed for many elements, the large RSDs reported for elements and the potential for outliers, the determination of environmental trace element burden using feathers is significantly enhanced by the analysis of multiple feathers using INAA.     

The application of INAA to the geochemical analysis of single diamonds

Instrumental neutron activation analysis (INAA) has been applied to the analysis of 62 small (0.01–0.5 carat), single, inclusion-bearing and inclusion-free diamonds from South Africa, Brazil and Colorado. Up to 40 elements were detected at the ppb and ppt levels in individual diamonds of the eclogitic (basaltic affinity) and the peridotitic (ultramafic) paragenesis. The data obtained in this study can be used to distinguish between diamonds from the eclogitic and peridotitic parageneses and provides geochemical information on the environment in which diamonds crystallize. Further, the technique may prove to be useful in fingerprinting diamonds of different provenance areas.     

Dithiophosphors?ure-O,O-diethylester zur Spurenanreicherung an Aktivkohle

Zusammenfassung Der für die Extraktion im stark sauren Medium geeignete Chelatbildner Dithiophosphorsäure-O,O-diethylester kann auch für die Spurensorption an Aktivkohle eingesetzt werden. Durch das unterschiedliche Sorptionsverhalten der Elemente ist es möglich, eine Gruppe von Elementspuren (Bi, Cd, Cu, In, Pb, Tl) selektiv aus verschiedenen Matrices abzutrennen. Am Beispiel der Analyse von Reinstgallium konnte gezeigt werden, daß die Kombination von Spurenabtrennung und mikrophysikalischem Bestimmungsschritt zu Nachweisgrenzen im ng/g-Bereich führt. Als Bestimmungsverfahren für die angereicherten Spuren wurden die Injektionsmethode der Flammen-AAS und die Schlaufen-AAS eingesetzt, da mit beiden Methoden bei sequentieller Messung noch Multielementbestimmungen aus Spurenkonzentraten von weniger als 1 ml möglich sind.

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Dithiophosphoric-acid-O,O-diethylester for trace enrichment on activated carbonI. Analysis of high-purity gallium and aluminium-determination of the element traces by flame-AAS (injection method and loop-AAS)

Summary The chelate complexing agent dithiophosphoric acid-O,O-diethylester, suitable for extraction from high acidity media, can also be put to use in trace sorption on activated carbon. Due to different sorption behaviour of elements, it is possible to separate selectively from different matrices, groups of elements (such as Bi, Cd, Cu, In, Pb, Tl). By way of example concerning the analysis of high-purity gallium, it could be demonstrated that by combination of a trace separation with a micro-physical determination step, detection limits in the ng/g-region could be reached. As a determination procedure regarding pre-concentrated traces, the injection method of flame-AAS and loop-AAS were applied, because both these methods allow sequential multielement determinations from trace concentrates of less than 1 ml.

     

Characterization of protein-bound metal species by bioanalytical and neutron activation techniques

Several bioanalytical techniques have been employed in conjunction with instrumental neutron activation analysis (INAA) to study metalloproteins and protein-bound trace elements in bovine kidneys. The accuracy of the INAA method developed has been evaluated by analyzing certified reference materials. Up to 29 elements can be reliably determined in biological tissue samples by INAA. Dialysis of the bovine kidney homogenate shows that more than 90% of Ca, Cd, Cu, Fe, Mg, Mn, Mo, Se, V and Zn, and about 20% of Br are bound to macromolecules, mainly proteins. A combination of gel filtration and ion exchange chromatography, chromatofocusing, electrofocusing, ammonium sulphate precipitation and INAA of the bovine kidney microsomecytosol subcellular fraction further indicates that much of the copper is associated with a single protein of an isoelectric point around 5 and a molecular weight of about 30 000 daltons. Some results on manganese proteins are also reported.     

Analytical procedure for the determination of thorium, zinc and potassium in diet samples

Instrumental neutron activation analysis (INAA), and atomic absorption spectrometry (AAS) have been used for the determination of trace amounts of thorium, zinc, and potassium in diet samples. Interlaboratory comparison has been made. The z-scores show that INAA can be used to determine thorium and zinc whereas AAS can be employed to determine potassium in diet samples.     

Dietary intake of zinc and selenium in Turkey

It is known that in the Turkish soil Se and Zn concentrations are somewhatlower than in other countries. Lower zinc intake causes significant healthproblems mostly at rural areas. Six different population groups, total of55 subjects, consisting of children, people from rural areas, university studentsand staff members were selected and diet samples were collected by duplicateportion technique. Bread and flour samples were collected from six differentbakeries in Ankara. Zinc, selenium and other trace elements in these sampleswere analyzed mostly by INAA. Daily dietary zinc intake differs among differentgroups, ranging 5–13 mg Zn/day, and for all cases, it is lower thanRDA value of 15 mg Zn/day. Similarly, selenium daily intake is around 20–53µg Se/day, which is also lower than RDA value of 55–70 µgSe/day.