仪器中子活化法测定金属钛中杂质元素

采用仪器中子活化法(INAA)测定了金属钛中锰、砷、锑、钽、钨等5种痕量杂质元素含量,分析中采用GEM 70P高纯锗γ谱仪及grammavision 32分析软件。经预处理的样品割成5mm×5mm×1mm大小的薄片,其质量约180mg,与标准一起置于反应堆中照射,中子通量为1.0×10~(13)cm~(-2)·s~(-1)。上述5种元素的探测下限依次为0.022,0.049,0.032,0.097,0.015μg。将方法用于分析水沉积物标准物质(GBW 07312),锰、钽、锑及钨4种元素的测定值与证书值相符。     

Instrumental Neutron Activation Analysis for Certification of Ion-Implanted Arsenic in Silicon

Standard reference material (SRM) 2134 Arsenic Implant in Silicon was produced at the National Institute of Standards and Technology (NIST) as a calibrant for secondary ion mass spectrometry. Instrumental neutron activation analysis was used as a primary method for certification of the arsenic implanted dose. A complete evaluation of all sources of uncertainty yielded an expanded relative uncertainty for the mean value of this SRM to be 0.38% at approximately the 95% level of confidence. No evidence indicating significant heterogeneity among samples was observed.     

Determination of Trace Elements in Liquid Fuels by Instrumental Neutron Activation Analysis

Abstract

An instrumental neutron activation analysis with Ge(Li) γ -spectrometry and computer-assisted data reduction, has been developed for the determination of more than 20 elements in different liquid fuels. Organo-metallic standard solutions were mixed to obtain suitable standards. Two neutron irradiations and 4 γ-spectrometric measurements are required for each sample. Corrections were taken into account for a few spectrometric and nuclear interferences. The overall standard deviation for nearly all elements is mainly determined by counting statistics. The following elements can be determined : Na, Al, S, Cl, K, Sc, V, Cr, Fe, Co, Ni, Cu, Zn, As, Se, Br and La whereas the concentration of the following elements are mostly near the limit of detection: Mg, Mo, Sb, Ba, Th and Hg.     

南极岩石样品中稀土元素的中子活化分析

用仪器中子活化分析技术,测定了南极岩石中8种稀土元素含量,讨论了不同岩石的稀土模式特点。     

Heavy metal determination in atmospheric particulate matter by Instrumental Neutron Activation Analysis

Instrumental Neutron Activation Analysis (INAA) is employed for its important analytical properties. Fundamentally, INAA is a multi-elemental technique allowing the determination of about 40 elements with a good Limit of Detection. In this paper we applied this nuclear technique to study the element composition in PM10 determining about 30 elements.25 filters were collected in downtown Rome from October 1999 to April 2000 and irradiated at the nuclear reactor Triga Mark II (ENEA-Casaccia Laboratories). The γ-ray measurements have allowed the quali- and quantitative analysis. The element levels in PM10 with the relative correlations have been determined: basically, the concentrations are very low.Furthermore, the enrichment factors of all elements will be reported in order to understand the natural or anthropogenic origins of the particulate matter: some elements may be attributed to long-range transport phenomena from other natural and/or anthropogenic sources.     

Determination of Heavy Metals as Environmental Pollutants: Use of Instrumental Neutron Activation Analysis

The simultaneous determination of heavy metals by instrumental neutron activation analysis (INAA) in some environmental samples have been considered. A new approach has been proposed to assess the potentialities and the most adequate use of INAA for each particular heavy metal.     

Determination of trace amounts of chlorine in hydraulic fluid by Instrumental Neutron Activation Analysis

A procedure has been developed for the determination by thermal neutron activation analysis of trace amounts of total chlorine in the Electro-Hydraulic-Control /EHC/ fluid used by the Hadera Power Station in various hydraulic systems. Irradiation for 1 min near the core of a nuclear reactor is followed by high resolution gamma-ray spectrometry using a Ge/Li/ detector. Chlorine amount is quantitatively determined by measuring the gamma-ray photopeaks of the radioactive nuclide³⁸Cl. The system response is linear in the concentration ranges investigated. Chlorine concentration in a fresh hydraulic fluid sample was found to be 17.6±0.5 ppm. The limit of detection, when assaying a 1 cm³ sample of fluid under the present experimental conditions, is 1 g of chlorine and the corresponding concentration is 1 ppm.     

人体子宫癌活组织中微量元素的中子活化分析

本文利用样品的低温干燥预处理技术和仪器中子活化分析方法,同时测定了人体子宫癌活组织中的29种微量元素,并分别与宫颈炎组织和正常组织比较,初步研究结果表明,子宫癌组织,宫颈炎组织和正常组织中Au,I,Se等微量元素有显著差异。     

Instrumental Neutron Activation Analysis of Trace Elements in Organs and Tissues of Zinc Deficient Mice

Eleven elements in ten organs and tissues of mice fed with Zn-deficient diet (Zn-def. mice) and those fed with control diet (control mice) were determined by INAA. Zinc concentrations in the organs of Zn-def. mice were not distinctly lower than those of control mice except for bone and pancreas, as similar to the predecessors' reported results. However, the Co content increased significantly in all the organs and tissues of Zn-def. mice compared with control mice. The organs and tissues observed were histologicaly normal and no typical symptoms of Zn deficiency disease were recognised. The results suggest that the change of Co-concentration may be regarded as a mark of the prestage for a Zn deficiency disease.     

Quantitative Evaluation of Trace Elements in Sediments of the Tamsui River via Instrumental Neutron Activation Analysis

The present study examined concentrations of trace elements in the sediments collected from 31 locations along the banks of Tamsui River by instrumental neutron activation analysis. The Tamsui River is famous for containing a unique area of naturally preserved mangrove in northern Taiwan. It is also the second longest river among the 3 major rivers in Taiwan. A total of 11 nuclides, including Mg, Al, Ti, Mn, Na, Sc, As, Br, La, Fe and Cs, were identified. The categories and measurements of nuclides detected were interpreted according to the sampling locations or chemical attributes characteristics. A dimensionless index (CI) was introduced to explore the quantitative correlation among the detected nuclides. A smaller CI corresponded to a stronger correlation between a pair of nuclides, such that the correlation between the nuclides can be interpreted through a series of quantified indices. The minimum detectable concentration (MDC) for As‐76 was fluctuated around 0.67 ± 0.09 μg/g due to the variations of background counts in various gamma spectra.     

Determination of Essential Elements in Ayurvedic Medicinal Leaves by k0 Standardized Instrumental Neutron Activation Analysis

Elemental concentrations of a few medicinal leaves are determined by instrumental neutron activation analysis using the single comparator (k ₀) method. Data obtained for neem leaves, collected from two different places, have been used to see the effect of soil condition. The applicability of the method particularly for the simultaneous determination of Ca, Mg, V and Al in biological matrices has been evaluated in terms of the detection limit, precision and accuracy. The method was validated by analysing the NIST Standard Reference Material (SRM-1571) and it was found that the elemental concentrations measured in SRM-1571 are within ±10% of the reported values.     

Instrumental Neutron Activation Analysis of Iodine Levels in Fourteen Seaweed Species from the Coastal Belt of Ghana

Fourteen seaweed species were sampled from October 1997 to May 1999 along the rocky shores of Ghana, which is being washed by the Gulf of Guinea (part of the Atlantic Ocean). Instrumental neutron activation analysis (INAA) was used to measure the iodine levels in the species, with the basic aim of selecting seaweed species that are rich in iodine and hence can be used as supplement in the diet of humans. This is to help solve the problems associated with iodine deficiency disorders (IDD). The levels of iodine found in the seaweed species ranged between 55 to 804 ppm. The precision, expressed in terms of relative standard deviation, and accuracy of measurements are within ±5–10%. The results show high variability in and between species and among sampling sites. The high values of iodine concentrations in the macroalgae suggest that these marine organisms can be used as supplement in the diet of humans.     

Ultra-trace nutritional and toxicological elements in Rome and Florence drinking waters determined by Instrumental Neutron Activation Analysis

In order to ascertain water quality for human consumption, the evaluation of trace and ultra-trace elements in drinking waters of two Italian cities, Rome and Florence, is investigated together with the potabilization processes involved and the relative human exposure to the contaminants. Through a multi-elemental detection with no chemical treatment using Instrumental Neutron Activation Analysis and Proton-Induced X-ray Emission the concentration of 40 elements is determined. Basically, the concentrations of the investigated parameters in drinking waters were within the permissible limits of the World Health Organization drinking water quality guidelines and the Water Pollution Control legislation of Italian authorities. The Rome drinking water shows a chemical water composition quite similar to uncontaminated natural water: potentially toxic elements (e.g., Cr, Hg, Ni, and Sb) are present at very low concentrations whereas the levels of nutritionally essential elements are adequate and low levels of I and Se cannot be considered a cause of deficiency diseases. A multivariate statistical approach was used to identify both the origins and correlations among elements and the six different apportionments contributing to the water supply in Rome. For the drinking waters distributed in Florence, the element levels show a sufficiently good situation, except for Al (range 103–267 μg/L) that is present at reasonable concentrations for almost the entire population due to the hard potabilization procedure involving aluminum salts. The values of Metal Index (MI), that helps to quickly evaluate the overall quality of drinking waters, show a good drinking water quality in Rome (Fe is the only element to be considered critical) whereas in Florence the situation is influenced by Al levels. No relevant differences are found among Rome and Florence water composition and other Italian and world potable waters.This study can be considered a useful reference for studies aimed to highlighting toxicological, nutritional and environmental disease patterns.     

Determination of Tellurium by Instrumental Photon Activation Analysis

Abstract

Tellurium has been determined at milligram and submilligram levels in the presence of uranium by a strictly instrumental photon activation ¹²¹ analysis procedure. The 575 keV gamma ray of Te was measured. At a decay time of three weeks, this gamma ray peak was interference-free. As little as 0.4 mg of tellurium was determined and the method evidences that sensitivity would increase with irradiation time.     

中子活化分析测定牛奶中的有机卤族化合物

1　引　　言由于有机卤族化合物污染的普遍性和突出的“三致”作用 (致癌、致突变、致畸形 ) ,有机卤族化合物的环境行为一直是环境化学的研究热点 ,也是世界各国重点控制的污染物。有机卤族化合物的分析测定一直由色谱完成 ,但由于该类化合物有成千上万种 ,色谱分析不可能对样品中的所有有机卤族化合物进行定性和定量分析。有研究表明 :色谱分析结果只占实际污染水平的 1%～ 2 6% ,并不能准确反映有机卤族化合物的总体污染水平。中子活化分析 (ＮＡＡ)是目前唯一一种能同时定量测定有机Ｃｌ、Ｂｒ和Ｉ的方法。本工作用中子活化分析测定了牛…     

Neutron Activation Analysis of Manganese Mercury Telluride

Procedure were proposed for the radiochemical neutron activation analysis of Mn _x Hg_1?xTe using an AV-17-HCl chromatography system for separating macro and micro components. Using a combination of procedures, one can determine 34 impurity elements in manganese mercury telluride at a concentration level of n × (10^?5?10^?10) wt %.     

Instrumental Activation Analysis of Meteorites Using Gamma-Gamma Coincidence Spectrometry

Abstract

A non-destructive procedure for the determination of iridium, sodium, nickel, cobalt, and scandium in a single meteorite sample is presented. The method utilizes neutron activation followed by gamma-gamma coincidence spectrometry. Iridium abundances are given for several meteorites and compared to values obtained by radiochemical separation methods. The non-destructive results differ significantly from previously published values for certain classes of meteorites, in particular the enstatite chondrites.     

Neutron Activation Analysis of Samples of Unknown Composition

The advantages of relative analytical methods over absolute methods for calculating element concentrations have been demonstrated. A procedure for the neutron activation analysis of samples of unknown composition was proposed based on the numerical simulation of the gamma spectra of test samples.