Muonic atom X-ray spectroscopy for non-destructive analysis of archeological samples

Journal of Radioanalytical and Nuclear Chemistry - The implementation in the RIKEN-RAL negative muons facility of a new muon beamline monitoring and novel digital data acquisition system for gamma...     

月球样品的中子活化分析技术研究

月球的起源是月球研究的核心问题。月球探测任务返回的数据和样品极大地提高了人类对地月系统的认知,同时也发现了更多未解之谜,亟待未来的探测任务和科学研究来解答。嫦娥五号月壤是我国首次地外天体采集返回的样品,也是继美国和苏联探月采样任务45年后人类再次获得的月球样品。鉴于月球样品的珍贵性和特殊性,利用先进技术开展其全元素含量的非破坏精准分析对于认识月球演化和月球资源就地开发利用具有重要的意义。依托大型核反应研究堆和加速器中子注量率优势,利用中子活化分析技术可实现月球样品中的全元素非破坏分析：1)仪器中子活化分析技术(INAA)可测量Na—U元素之间的60余种元素;2)瞬发γ中子活化分析技术(PGNAA)可补充测量INAA不适合测量的元素如H、B、C、N等;3)中子深度剖面分析技术(NDP)可测量样品近表面(微米级)聚变能源³He的浓度深度分布;4)缓发中子测量技术(DNC)可定量样品中痕量裂变核素如²³⁵U和²³⁹Pu,并结合INAA可测量²³⁸U/²³⁵U同位素比值;5)14 Me...     

Radioanalytical methods based on the radioactive indicator principle

Some new radioanalytical methods based on the radioactive indicator principle are discussed. A new classification for radioanalytical methods is proposed.     

Radioanalytical methods in the hot atom chemistry of sulfur in inorganic systems

The paper presents a comprehensive review of radioanalytical methods for chemical identification of radioactive sulfur atoms recoiling in neutron irradiated (or implanted) inorganic systems.     

Development of non-destructive isotopic analysis methods using muon beams and their application to the analysis of lead

Journal of Radioanalytical and Nuclear Chemistry - Elemental isotopic ratios are measured in various research fields and provide useful information regarding age, origin, geological and biological...     

Monte Carlo and experimental efficiency calibration of gamma-spectrometers for non-destructive analysis of large volume samples of irregular shapes

A comparison of efficiency calibration of a HPGe gamma-ray spectrometer applied for non-destructive analysis of gamma-ray emitters in large volume samples of irregular shape is presented. The detector efficiency calibration was carried out during the analysis of cosmogenic radionuclides (⁶⁰Co, ⁵⁴Mn, ²²Na and ²⁶Al) in fragments of the Ko?ice meteorite. Fourteen meteorite fragments were available for the analysis with masses from 27 to 2,163 g. A reasonable agreement in the estimation of the HPGe detector efficiency was obtained using the Monte Carlo simulation GEANT 3 code, and the experimental calibration using radioactive standards mixed with iron–silica–copper powder housed in mock-ups of similar shapes as the original samples. The differences in the efficiency estimation obtained by both methods were within 10 %. It is recommended that the Monte Carlo simulation of the detector efficiency can be applied in routine analysis of gamma-ray emitters in large volume samples of regular or irregular shapes.     

Activation analysis of alkaline rocks. A comparison between destructive and non-destructive methods

The United States Geological Survey reference sample AGV-1 andesite, and three alkaline rocks from the apatite mine of Jacupiranga, Brasil, were analyzed by thermal neutron activation analysis using destructive and non-destructive methods, and high resolution Ge(Li) gamma-ray detectors. One of the rocks, a carbonatite, was also analyzed by instrumental activation analysis with epithermal neutrons. A greater number of elements can be determined using the radiochemical separation, but the precision and accuracy attained by INAA and RNAA were of the same order for most of the elements analyzed. Epithermal activation was more advantageous for tantalum, terbium and holmium. Comparison of the analytical results for USGS reference sample (AGV-1) with the data published by others gave good agreement. Statistical tests used for comparison of the results of destructive and non-destructive methods, as well as other results are presented.     

Visible and near-infrared chemical imaging methods for the analysis of selected forensic samples

This study investigated various chemical imaging methods for the forensic analysis of paints, tapes and adhesives, inks and firearm propellants (absorption and photoluminescence in the UV-vis-NIR regions). Results obtained using chemical imaging technology were compared with those obtained using traditional techniques. The results show that chemical imaging offers significant advantages in the forensic context, for example the ability to display visual and spectral results side by side and to reduce sample preparation, hence minimizing the risk of contamination. Chemical imaging produced a greater discriminating power than traditional techniques for most evidence types. Chemical imaging also eliminated different brands of ammunition based on the fluorescence characteristics of the propellant grains preserving the evidence for further analysis. It is expected that this technology will find broader forensic applications in the future.     

Instrumental neutron activation analysis of lunar samples and the identification of primary matter in the Lunar Highlands

We describe the scheme of sequential neutron activation which was developed in our laboratory especially for the analysis of lunar samples and in which more than 50 elements are determined. Irradiations with 14 MeV, epithermal and thermal neutrons and both instrumental techniques and radiochemical separations were applied. It is shown that the achieved accuracy can compete with the best available analytical methods for most major and many trace elements. Besides the observation of “correlated elements”, the discovery of primary matter of the last accretion stage of the moon in samples from the lunar highlands is discussed in some detail.     

Radioanalytical methods for the accurate determination of227Ac and228Th in irradiated226Ra targets

Alpha spectrometry is proposed for the quantitative analysis of²²⁷Ac and²²⁸Th in irradiated²²⁶Ra targets. The chemical separation and the radiochemical determination is described.     

Destructive and non-destructive methods for the determination of micro-trace amounts of antimony in high purity silicon by neutron activation analysis

Destructive and non-destructive methods have been used for the determination of microtraces of antimony in high-purity silicon powder. The destructive method was based on substoichiometric radioactivation analysis with solvent extraction using BPHA and cupferron as organic reagents. The antimony contents in high-purity silicon can be determined by the proposed method.     

Radioanalytical application of sub- and super-equivalence method of isotope dilution analysis

The values of Sb(III), Tl(I), Te(IV), and biological substance, DNA determined by sub- and super-equivalence method of isotope dilution analysis (SSE-IDA) and substoichiometric isotope dilution analysis (Subst-IDA) under the same condition were compared. From the results, it was proved that SEE-IDA did not need the strict condition necessary for Subst-IDA and the determination by SEE-IDA was possible within the error of a few percent, and the range of determination was wider than that of Subst-IDA. The various variants of SSE-IDA reported so far were classified into SEE-Reverse-IDA and SEE-Direct-IDA. Finally, the characteristics of SEE-IDA allowing accurate determination were discussed and summarized.     

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.     

Radioanalytical procedures for the characterization of fly-ASH leaching by water

The use of neutron activated fly ash to measure its leaching by water is discussed. Results can be expressed by a simple mathematical equation which permits the characterization of the process in terms of four parameters.     

Recent developments in methods and technology for analysis of biological samples by MALDI-TOF-MS

Matrix-assisted laser desorption/ionization–time-of-flight mass spectrometry (MALDI-TOF-MS) is widely used in a variety of fields because it has the characteristics of speed, ease of use, high sensitivity, and wide detectable mass range for obtaining molecular weights and for structural characterization of macromolecules. In this article we summarize recent developments in matrix additives, new matrices, and sample-pretreatment methods using off-probe or on-probe techniques or nanomaterials for MALDI-TOF-MS analysis of biological samples.     

Validationof chromatographic methods of analysis of drugs in biological samples

Chromatographic techniques such as high-performance liquid chromatography and gas chromatography have been extensively exploited as powerful analytical tools for the determination of therapeutic levels of drugs and their metabolites in biological samples. Good laboratory practice necessitates statistical validation of chromatographic assays with respect to specificity, limit of detection, accuracy, precision, linearity and recovery.     

CAMAC-based instrumentation for a non-destructive neutron activation analysis system

The measuring system described in this paper, developed for non-destructive neutron activation analysis, consists of a semiconductor detector gamma-ray spectrometer and a sample changer coupled to a PDP-9 computer via a CAMAC interface system. CAMAC modules implemented in this system are an ADC interface, a sample changer control, display unit, a timer and a time-of-the-year clock. The spectra are accumulated in a section of the computer memory. The computer is further used for experiment control and for the analysis and interpretation of the measured gamma-ray spectra.