Neutron Activation Analysis for Trace Element Determination in Geostandards

The advantages of neutron activation analysis as applied to geological material are discussed. Analytical work performed in the authors' laboratories is described, and preferred values from this work for 38 elements in some USGS standard rocks are presented and compared with literature data.     

Instrumental Neutron Activation Analysis Of French Geochemical Reference Samples

Instrumental neutron activation analytical data, for eighteen trace elements (Ba, Co, Cr, Cs, Hf, Rb), Sb, Sc, Ta, Th, La, Ce, Nd, Sm, Eu, Tb, Yb, Lu), Hd₂O and Fe₂0₃ in eleven French geoche-mical reference samples are presented and discussed briefly.     

Instrumental Neutron Activation Analysis Of 37 Geochemical Reference Samples

37 geochemical reference samples, issued mostly by the U.S. Geological Survey and the "Centre de Recherches Pétrographiques et Géochi-miques", have been analysed for more than twenty trace elements using instrumental neutron activation technique. The results are compared with published data; in most oases, the agreement is good.     

Instrumental Neutron Activation Analysis of Twenty-Nine International Geochemical Reference Samples

Results of measurements of twenty-seven elements, most of them in trace amounts, by Instrumental Neutron Activation Analysis (INAA) in twenty-nine international geochemical reference samples from Canada, U.S.A., Japan, France and South Africa, are reported and compared with available literature values. In general, our data agree well with literature values. The disagreement of our results (e.g., Zr in Canadian syenites and several trace elements in USGS ultrabasic rocks) with those reported by other workers is briefly discussed and ways of improving INAA are pointed out. The present report includes data on several trace elements for which existing data are rather scarce.     

Determination of Trace Elements in Selected Geological Reference Materials by Instrumental Neutron Activation Analysis

Data are presented for eight rare earth elements and ten other elements in 22 reference samples recently distributed by the University of Liege (Belgian sedimentary rock reference samples), the Geological and Mining Service (Suriname), the Geological Survey of Japan and the Venezuelan laterite. Determinations were made using a well characterised, high precision, neutron activation analysis technique.     

Analysis of NBS Coal Standard Reference Materials 1632a and 1635 by Instrumental Neutron Activation Analysis

NBS SRM 1635 and NBS SRM 1632a were analyzed for trace and minor element contents by instrumental neutron activation analysis. The results of these analyses show excellent agreement with NBS certified values and/or literature values.     

Provisional Elemental Values for IAEA‐Sewage Sludge by Instrumental Neutron Activation Analysis

The International Atomic Energy Agency (IAEA) organised a proficiency test (PT), IAEA‐CU‐2010‐02, for the determination of elements in sewage sludge. The PT sample was analysed by semi‐absolute standardless k₀‐instrumental neutron activation analysis (k₀‐INAA). Results for seven elements (As, Co, Cr, Fe, Hg, Se, Zn) were submitted to the IAEA by our laboratory. All of our results were scored ‘acceptable’ by the ‘result evaluation criteria’ adopted by the IAEA. The same analytical methodology produced quantitative results for twenty‐six additional elements. In total, thirty‐six elements were determined with uncertainty varying from 4 to 11%. This paper presents the provisional mass fractions of twenty‐six additional elements (Ag, Al, Br, Ca, Ce, Cl, Dy, Eu, Ga, Hf, I, K, La, Mg, Mn, Na, Rb, Sb, Sc, Sm, Ta, Tb, Th, V, U, W) not reported by the IAEA. The analytical methodology was discussed with important sources of spectral, nuclear and fission‐product interferences. It was shown that the important components of uncertainties were the k₀ factor, Q₀ factor, detector efficiency, mass and counting statistics. The methodology was validated by analysing the IAEA‐S7 reference material.     

Instrumental Neutron Activation Analysis of Nine New Reference Materials from the Geological Survey of Japan

Nine reference materials, recently distributed by the Geological Survey of Japan (JA-1, JB-la, JB-2, JB-3, JG-la, JGb-1, JP-1, JR-1 and JR-2) have been analysed by instrumental neutron activation analysis using well proven experimental techniques. Results for the twenty elements determined (selected rare earth elements, Fe, Ba, Co, Cr, Cs, Hf, Rb, Sc, Ta, Th and U) are assessed for accuracy and precision and show good agreement with previously published data.     

Instrumental Neutron and Photon Activation Analysis in the Geochemical Study of Phonolitic and Trachytic Rocks

More than 130 samples of Tertiary phonolitic, trachytic and trachyandesitic rocks, representing evolved members of strongly and weakly alkaline volcanic rock series of the Ohre (Eger) Rift in the Bohemian Massif, Czech Republic, were analysed by instrumental neutron and photon activation analysis (INAA and IPAA, respectively). Forty-two major and trace elements were determined to explain the origin of such evolved rocks. Specific features of INAA and IPAA of the silicic, highly alkaline rocks are discussed, and results for selected samples are given.     

Instrumental Neutron Activation Analysis of Estuarine Sediment as a Proposed Reference Material for Environmental Studies

The International Atomic Energy Agency (IAEA) Marine Environmental Studies Laboratory (MEL) organised an intercomparison exercise, through its Analytical Quality Control Services (AQCS), for the determination of trace elements in estuarine sediment IAEA-405, well suited for the characterisation of sediments. The instrumental neutron activation analysis technique (INAA) was developed using a 27 kW low power research reactor. Forty elements in the sediment were determined with a measurement precision varying from 1.8% to 12.3%. IAEA reference materials SL-1 and SD-M-2/TM were analysed throughout this work as quality assurance samples.     

Instrumental Neutron Activation Analysis of Two French Geochemical Reference Samples - Basalt BR and Biotite Mica-Fe

Instrumental neutron activation analysis results for 20 trace elements (Sc, Cr, Co, Ni, Rb, Cs, Ba, La, Ce, Nd, Sm, Eu, Gd, Tb, Tm, Yb, Lu, Hf, Ta, Th) and for two major elements (Na and Fe) in two geochemical reference samples issued by the "Centre de Recherches Pétrographiques et Géochimiques" are reported and compared with available literature values. In general our results agree well with recommended or proposed values.     

Instrumental Neutron Activation Analysis by Collecting Only One Spectrum: Results For International Geochemical Reference Samples

Instrumental neutron activation analysis of rocks and minerals is currently done on basis of collecting 2 or 3 energy spectra. We have found that, by collecting one spectrum one week after irradiation, satisfactory results for the USGS and CRPG geochemical reference samples can be obtained.     

Instrumental Neutron Activation Determination of 23 Elements in 8 New USGS Standard Rocks

The trace elements Ce, Co, Cr, Cs, Dy, Eu, Gd, Hf, La, Nd, Ni, Rb, Sb, Sc, Sm, Ta, Tb, Th, Tm, U, V, Yb and Zr have been determined by instrumental neutron activation analysis and U by delayed neutron counting in the USGS standard rock samples STM-1, RGM-1, QLO-1, SDC-1, BHVO-1, SCo-1, SGR-1 and MAG-1. The results are compared with those found in the literature.     

Instrumental Thermal Neutron Activation Determination of 20 Elements in Nineteen Silicate Reference Materials

Elemental concentrations of Al, Ba, Ca, Ce, Co, Cr, Cs, Dy, Eu, Fe, Hf, Mn, Na, Rb, Sb, Sc, Ta, Th, Ti and V have been measured in 11 USGS, 6 CCRMP and 2 NBS reference materials by instrumental thermal neutron activation analysis. The results are compared with recent consensus and agency values.     

Combination of ICP-AES and Instrumental Neutron Activation Analysis as Effective Methods for Studying Distribution of Elements in Soil and Plants

A detailed characterisation was carried out for soil sampled from sites with different levels of contamination before and after the cultivation of oats and barley. Mineralogical composition, concentration of exchangeable cations, dynamics of soil pH and acid neutralisation buffer capacity of the soil were studied. A total of 21 elements in the soil and 28 elements in the plants were determined by instrumental neutron activation analysis. Distribution of Al, Cr, Mn, Fe, Co, Ni, Cu, Zn and Pb in soil leachates was studied by sequential leaching procedure and ICP-AES. It was found that plants significantly affect most of the soil characteristics including the leaching of heavy metals.     

超热中子活化法测定碘和溴

介绍了采用微型反应堆超热中子活化分析膳食样品中Ｉ和Ｂｒ的方法。讨论了热中子屏蔽材料的选择,干扰扣除等问题,计算了不同样品的探测极限及标准偏差。对几种标样进行分析,其结果与推荐值相符。     

中子活化分析在铼—锇法年龄测定中的应用

同位素稀释中子活化分析铼与感耦等离子体质谱法测定锇相结合，应用于辉钼矿及铜＿镍硫化物矿物的铼＿锇年龄测定，取得了满意的结果，扩大了铼＿锇测年法的应用范围。     

Some Trace-Element Contents of Biotite, Btt-1, and Hornblende, Hbl-I, by Semiquantitative Spectrographic Analysis and by Instrumental Neutron Activation Analysis

Some trace-element contents of U.S. Geological Survey (USGS) samples, biotite Btt-1 and hornblende Hbl-1, were determined by both computerized semi-quantitative spectrographic analysis and instrumental neutron activation analysis. An equal number of portions of the Centre de Recherches Pétrographiques et Géochimiques (CRPG) samples, biotite Mica-Fe and phlogopite Mica-Mg, were randomized with portions of the USGS samples and analyzed simultaneously to allow direct comparisons of trace elements in the biotites. Mica-Fe has concentrations of Cs, Hf, Ta and Zn that are greater by factors of 3 or more than those in Btt- 1. Although the Co contents of the two biotites are nearly equal, the amounts of Cr, Sc, La and the rare earth elements are significantly greater in Btt-1. Mica-Mg contains larger amounts of Cs and Rb than does Hbl-1, whereas the Cr content of Hbl-1 is 15 times that of Mica-Mg. Btt-1 and Hbl-1 may be useful as comparison samples for the analysis of biotites and hornblendes after other data are available.     

Instrumental Neutron Activation Analysis of Silicate Rock Standards AN-G, BHVO-1, QLO-1, RGM-1, and STM-1

Silicate rock standards AN-G, BHVO-1, QLO-1, RGM-1, SDC-1 and STM-1 have been analyzed for 7 REE (La, Ce, Sm, Eu, Tb, Yb and Lu), Na₂O, FeO_t, Sc, Co, Cr, Ta, Hf and Th by instrumental neutron activation analysis. The mean values are compared to those from other studies reported in the literature.     

Multielemental Neutron Activation Analysis of Chinese Geochemical Reference Samples

The concentrations of 36 elements in geochemical reference samples issued by the Ministry of Geology and Mineral Resources of China were determined by neutron activation analysis. Three main variants of the technique, instrumental, epithermal, and nreirradiation separation neutron activation analysis (INAA, ENAA, PNAA), were employed in a systematic study of the samples by three laboratories: the Institute of Atomic Energy of the Academia Sinica (INAA, ENAA), the Institute of High Energy Physics of the Academia Sinica (INAA), and the Institute of Geophysical and Geochemical Prosnecting of the Ministry of Geology and Mineral resources (INAA,PNAA). Both long and short irradiations and both Ge(Li) and HPGe detectors were used. A supplementary software nackage for data processing was developed. About 81% of the data determined by neutron activation agreed with recomended values with in 15%.