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1.
Summary All-rounders and experts are two basic types of scientists. A harmonic cooperation between these two groups is essential for today's large study groups engaged in materials development. Materials development programmes in many high-tech countries are major fields of research supported by special financial arrangements (e.g. COST, EURAM or BRITE-programmes in Europe). Modern materials development is not possible without analytical guidance. This is not always realized by all engaged partners and it is a main obligation of analytical chemists to make aware of the role of a potent materials characterization in relevant development programmes. This should be demonstrated in two essential relevant areas: a) Bulk trace and ultra trace analysis of metals. Many important metal properties are directly or indirectly influenced by trace elements. In complex systems like fusion reactors or microelectronic components, trace contents of even minor metal parts might decisively influence system properties. As refractory metals and their silicides gain rising importance in VLSI microelectronic applications, their ultratrace characterization becomes a major challenge. Essential progress was possible by the complementary application of mass-spectrometric methods. Latest results and a critical survey will be given, including GDMS, SIMS, SSMS, IDMS and ICP-MS.Surprisingly, however, highest sensitivities and best detection limits were recently achieved by a combination of trace-matrix separation procedures and final end determination with ICP-MS. This combination also proved to be the most economic and safest approach from the view point of accuracy and precision. b) The analytical characterization of discontinuities and heterogeneities in solid matter. Practical examples are again taken from the study of refractory and hard metals and ceramics. A survey is given as to the manifold effects, heterogeneities and discontinuities exert on modern high-tech materials: as a function of their average diameter, they can either strengthen the material (dispersion strengthening), or they can cause deterioration of material properties e.g. as points of crack initiation, by grain boundary embrittlement etc. Together with most important methods for detection and characterization of heterogeneities and discontinuities, their evaluation and possible prevention during materials fabrication are discussed and pertinent examples are given. The phenomena of heterogeneous particles and pores are elucidated in more detail.

Acronyms used

1 Abbreviations for European research programmes AGATA Advanced Gas Turbines for Automobiles - BRITE Basic Research for Industrial Technologies for Europe - COST Cooperation in Science and Technology - EURAM European Research Activities Programme on Materials 2 Abbreviations in the field of refractory metals technology ADM Ammonium-Di-Molybdate - APT Ammonium-Para-Tungstate - HP High Purity - MHC Molybdenum-based alloy containing 1.2% Hf and 0.1% C - NS Non-sag (tungsten, used for lamp filaments and evaporative metallization techniques) - ODS Oxide Dispersion Strengthened - RM Refractory Metal - TZM Molybdenum-base alloy containing 0.5% Ti, 0.08% Zr and 0.025% C - UHP Ultra High Purity - VLSI Very large scale integration - ZHM Molybdenum-base alloy containing 0.40% Zr, 1.2% Hf and 0.15% C 3 Analytical technique names AA Activation Analysis - AAS Atomic Absorption Spectrophotometry - AES Auger Electron Spectrometry or Atomic Emission Spectrometry (only used in this work where it is clear that Auger Electron Spectrometry is not meant) - EDX(RS) Energy Dispersive X-Ray Spectrometry - EELS Electron Energy Loss Spectrometry - EP(X)MA Electron Probe X-Ray Microanalysis - GDMS Glow Discharge Mass Spectrometry - GFAAS Graphite Furnace Atomic Absorption Spectrometry - ICP-OES, MS Inductively Coupled Plasma — Optical Emission Spectrometry, Mass Spectrometry - ID-MS Isotope Dilution — Mass Spectrometry - LAS Classical photometry (Liquid Absorption — Spectrophotometry) - LEED Low Energy Electron Diffraction - MS Mass Spectrometry - NAA Neutron Activation Analysis - OES Optical Emission Spectrometry - SEM Scanning Electron Microscopy - SIMS Secondary Ion Mass Spectrometry - SSMS Spark Source Mass Spectrometry - TEM Transmission Electron Microscopy - TMS Trace-Matrix Separation (procedure) - WLD(-XRS) Wave Length Dispersive — XRS - XR(F)S X-Ray (Fluorescence) Spectrometry  相似文献   

2.
Summary We will present computer programs to analyze PDMS-spectra and to simulate the fragmentation of molecules in PDMS (Plasma-Desorption Mass Spectrometry), even of those with high masses.  相似文献   

3.
Using Fast Atom Bombardment Mass Spectrometry and Mass Spectrometry/Mass Spectrometry, the structure of HC-toxin a metabolite of Helminthosporiumcarbonum, is postulated to be structure 3.  相似文献   

4.
The applicability of GDMS, SIMS, SSMS, NAA and TMS with AAS, ICP-OES and ICP-MS end determination for routine bulk ultratrace analysis of high purity refractory metals was investigated. Due to the heterogeneous distribution of trace elements in the sub-ppm range, sample consumption and analysis time have a tremendous influence on quantification with procedures of low sample consumption. As an example, GDMS, which is commonly used for ultrapure material certification by most of the manufacturers in Europe and the USA, exhibits discrepancies by more than one order of magnitude for repetitive analyses of a series of trace components in the same sample. Furthermore, results of different laboratories using the same instrument are frequently not comparable. Due to easy standardization and large sample consumption TMS procedures combined with FAAS, GFAAS, ICP-AES and ICP-MS as methods of end determination exhibit better precision and accuracy than GDMS and SIMS. Detection limits are comparably low or even better in case of ICP-MS end determination. TMS procedures are less expensive and less time consuming than highly sophisticated analytical techniques like GDMS, SIMS or NAA. Additionally, they can be easily applied by experienced personnel in a well equipped industrial analytical laboratory.List of Acronyms Used AAS Atomic Absorption Spectrometry - FAAS Flame Atomic Absorption Spectrometry - GDMB Gesellschaft Deutscher Metallhütten- und Bergleute - GDMS Glow Discharge Mass Spectrometry - GFAAS Graphite Furnace Atomic Absorption Spectrometry - ICP-AES Inductively Coupled Plasma Atomic Emission Spectrometry - ICP-MS Inductively Coupled Plasma Mass Spectrometry - IDMS Isotope Dilution Mass Spectrometry - NAA Neutron Activation Analysis - SIMS Secondary Ion Mass Spectrometry - SSMS Spark Source Mass Spectrometry - TMS Trace-Matrix Separation - VLSI Very Large Scale Integration - XRFS X-Ray fluorescence Spectroscopy Dedicated to Professor Günther Tölg on the occasion of his 60th birthday  相似文献   

5.
I. Lavilla 《Talanta》2009,80(1):109-116
In this work, ultrasound-assisted emulsification with a probe system is proposed as a rapid and simple sample treatment for atomic spectrometric determinations (Electrothermal Atomic Absorption Spectrometry, Inductively Coupled Plasma Optical Emission Spectrometry, Flame Atomic Absorption Spectrometry and Cold Vapour Atomic Absorption Spectrometry) of trace elements (As, Cd, Cr, Cu, Hg, Mg, Mn, Ni, Sr and Zn) in cosmetic samples such as shampoos, gel (hair gel), crèmes (body milk, hair conditioner) and oil (body oil). The type of dispersion medium, the sample mass-to-dispersion medium volume ratio, as well as the parameters related to the ultrasound-assisted emulsification (sonication amplitude and treatment time) were exhaustively studied. Only 1 min of ultrasonic shaking and a dispersion medium containing 0.5% (w/v) of SDS + 3% (v/v) of HNO3 or HCl allows obtaining a stable emulsion at least for 3 months. Thermal programs, nebulization of emulsions, speed of pumps and concentration of reagents used in cold vapour generation were optimized. Calibration using aqueous standards was feasible in all cases. Calibration by the standard addition method and recovery studies was also applied for validation. Microwave-assisted digestion and Inductively Coupled Plasma Mass Spectrometry were used for comparison purposes. Relative standard deviations from analysis of five independent emulsions were less than 9% in all cases.  相似文献   

6.
Quantitative analyses of in situ boron‐doped SiGe composition on production wafers for 14 and 20‐nm logic devices were successfully characterized using advanced, small area Time‐of‐Flight Secondary Ion Mass Spectrometry analysis methods. The quantification of dopant levels in SiGe offered an improved method for tool‐to‐tool matching, process monitoring, and improvement, and performing this function accurately was necessary to enable advanced SiGe technology development that ensured world class manufacturing requirements were met. The boron concentration was measured with Time‐of‐Flight Secondary Ion Mass Spectrometry, based on a single Si1‐xGex/Si on silicon substrate standard, which exhibited excellent matching with corresponding inline XRF intensity data. Time‐of‐Flight Secondary Ion Mass Spectrometry accurately characterized SiGe composition with adequate sensitivity to detect small boron concentration variations to fine‐tune process parameters. This provided insight to the relationship between overlap capacitance and Rodlin measurements with SiGe dopant levels and ultimately led to device performance improvement.  相似文献   

7.
聚苯胺及聚邻甲基苯胺的直接裂解质谱研究   总被引:1,自引:0,他引:1  
本文用直接裂解质谱和裂解色谱/质谱研究了不同氧化程度聚苯胺(PAn)和聚邻甲基苯胺(POT)的裂解过程及链结构,并用碰撞诱导解离(CID)和联合扫描(B/E)等技术探讨了链的断裂机理。结果表明,聚苯胺及其衍生物在650℃下裂解时产生5个单元的线状齐聚物,PAn及POT中苯二胺和醌亚胺两种结构单元共存。并提出了PAn和POT的自由基过渡态热解机理。  相似文献   

8.
 Methods are described for the accurate and precise determination of lead concentrations and the isotopic composition of lead in wine samples using Inductively Coupled Plasma Mass Spectrometry (ICP-MS). This method needs little sample preparation. A comparison with lead isotope ratios measured by Thermal Ionization Mass Spectrometry (TIMS) in three wine samples reveals a good agreement between the two techniques. The lead concentration in three certified wine samples were measured by isotope dilution (ID) and the results are compared with those obtained by external calibration ICP-MS. Received: 10 June 1996/Revised: 23 September 1996/Accepted: 30 September 1996  相似文献   

9.
Identifying research users, applications, and impact is important for research performers, managers, evaluators, and sponsors. Identification of the user audience and the research impact is complex and time consuming due to the many indirect pathways through which fundamental research can impact applications. This paper identified the literature pathways through which two highly-cited papers of 2002 Chemistry Nobel Laureates Fenn and Tanaka impacted research, technology development, and applications. Citation Mining, an integration of citation bibliometrics and text mining, was applied to the >1600 first generation Science Citation Index (SCI) citing papers to Fenn's 1989 Science paper on Electrospray Ionization for Mass Spectrometry, and to the >400 first generation SCI citing papers to Tanaka's 1988 Rapid Communications in Mass Spectrometry paper on Laser Ionization Time-of-Flight Mass Spectrometry. Bibliometrics was performed on the citing papers to profile the user characteristics. Text mining was performed on the citing papers to identify the technical areas impacted by the research, and the relationships among these technical areas.  相似文献   

10.
The Electrospray Mass Spectrometry (ES-MS) of eight different supramolecular complexes shows that the molecular peaks of the desolvated multiply charged cations can be recorded more easily than by Fast-Atom-Bom-bardment Mass Spectrometry (FAB-MS) measurements of similar compound. The preliminary application of the ES-MS technique to self-assembled helical complexes obtained from ligands L3 to L8 with various metal ions (Cu, Co, Eu, Tb) indicates that ES mass spectra qualitatively reflect the species present MeCN solution.  相似文献   

11.
Natural products black cumin—Nigella sativa (N. sativa) and wild garlic—Allium ursinum (AU) are known for their potential role in reducing cardiovascular risk factors, including antracycline chemotherapy. Therefore, this study investigates the effect of N. sativa and AU water and methanolic extracts in a cellular model of doxorubicin (doxo)-induced cardiotoxicity. The extracts were characterized using Ultraviolet-visible (UV-VIS) spectroscopy, Fourier-transform infrared (FT-IR) spectroscopy, Liquid Chromatography coupled with Mass Spectrometry (LC-MS) and Gas Chromatography coupled with Mass Spectrometry (GC-MS) techniques. Antioxidant activity was evaluated on H9c2 cells. Cytosolic and mitochondrial reactive oxygen species (ROS) release was evaluated using 2′,7′-dichlorofluorescin-diacetate (DHCF-DA) and mitochondria-targeted superoxide indicator (MitoSOX red), respectively. Mitochondrial membrane depolarization was evaluated by flow cytometry. LC-MS analysis identified 12 and 10 phenolic compounds in NSS and AU extracts, respectively, with flavonols as predominant compounds. FT-IR analysis identified the presence of carbohydrates, amino acids and lipids in both plants. GC-MS identified the sulfur compounds in the AU water extract. N. sativa seeds (NSS) methanolic extract had the highest antioxidant activity reducing both intracellular and mitochondrial ROS release. All extracts (excepting AU methanolic extract) preserved H9c2 cells viability. None of the investigated plants affected the mitochondrial membrane depolarization. N. sativa and AU are important sources of bioactive compounds with increased antioxidant activities, requiring different extraction solvents to obtain the pharmacological effects.  相似文献   

12.
Summary The rapid progress in high technology constantly poses new challenges for Analytical Chemistry and prompts the development of new techniques and procedures. The influence is particularly strong in surface and interface analysis, which is developing at a rapid pace. This paper discusses some of the frontier areas like high-resolution depth-distribution analysis of trace elements, quantitative depth distribution analysis of ultra thin-layer systems, quantitative trace element analysis in monolayers, 3-dimensional stereometric analysis, molecular analysis, in-situ atomic resolution analysis of surfaces (chemical nanoscopy). Methodological approaches are discussed as well as results obtained mainly with solid state mass spectrometry and atomic force microscopy.Abbreviations and acronyms AES Auger Electron Spectrometry - AEM Analytical Electron Microscopy - AFM Atomic Force Microscopy - BSE Back Scattered Electrons - EPMA Electron Probe Micro Analysis - LRI-SNMS Laser Resonance Ionization Sputtered Neutrals Mass Spectrometry - SE Secondary Electrons - SEM Scanning Electron Microscopy - SIMS Secondary Ion Mass Spectrometry - STM Scanning Tunneling Microscopy - TEM Transmission Electron Microscopy - TOF-MS Time-of-Flight Mass Spectrometer - TXRF Total Reflection X-Ray Spectrometry - XPS X-Ray Photoelectron Spectroscopy Dedicated to Professor Dr. Wilhelm Fresenius on the occasion of his 80th birthday  相似文献   

13.
Summary The characterization of oxide scales by their composition and structure is necessary in order to predict their protective behaviour for the high temperature alloys in various corrosive media. For this purpose information obtained by classical methods, such as metallography, X-ray diffraction and microprobe analysis can be supplemented by depth profiles determined by various spectroscopical methods.In this paper, HASTELLOY X und INCONEL 617 were oxidized for relatively short times in two different atmospheres. Depth profiles were determined by GDOS (Glow Discharge Optical Spectroscopy), SNMS (Secondary Neutral Mass Spectrometry) and SIMS (Secondary Ion Mass Spectrometry).The measured profiles were compared with the results of non-destructive X-ray diffraction analysis to characterize the scales and the oxide-metal interface.  相似文献   

14.
Experimental evaluation on the use of239Pu spike in Isotope Dilution-Thermal Ionization Mass Spectrometry (ID-TIMS),238Pu spike in Isotope Dilution Alpha Spectrometry (IDAS) and233U as a Non-Isotopic Diluent in Alpha Spectrometry (N-IDAS), for determing plutonium concentration in samples with burn-up values in the range of 1,000–10,000 MWD/TU is done. Precision is determined by analyzing replicate aliquots from different samples using each of the three spikes. Accuracy is established by comparing the results with those obtained by using well recognized spike242Pu in ID-TIMS. It is shown that the use of239Pu spike with the latest generation thermal ionization mass spectrometers gives the best precision (0.2%), whereas the precision values of 0.5 and 1% can be obtained by using238Pu and233U spikes, respectively, on a routine basis. Reasons for the difference in the precision values are discussed, along with the merits and drawbacks on the use of different spike isotopes.  相似文献   

15.
Negative Ion Fast Atom Bombardment Mass Spectrometry is conducted on potassium pertechnetate evaporated onto a copper probe. The mass spectra of pertechnetate /TcO 4 / reveal the presence of mononuclear and polynuclear technetium oxo species which form general series TcnO n+1 ,...TcnOn+4 with n=1 to 5. The polynuclear species are believed to be formed via gas phase reactions.  相似文献   

16.
《Tetrahedron》1987,43(15):3413-3420
Stereospecific ion-molecule reactions of chiral reagents such as amino-alcohol with Mr,s,r and Ms,r,s enantiomeric alcohols (both menthols with R- and S-hydroxylic groups, respectively) yield both diastereomeric (Mr,r,s + AsH - H2O)+ and (Ms,r,s + AsH - H2O)+ ions. This specific gas phase synthesis combined with Mass Spectrometry/Mass Spectrometry analysis was applied to differentiate enantiomeric alcohols. Indeed,respective MIKE/CID spectra present differences in the daughter ion abundances which are useful for distinguishing between the initial alcohol configurations.  相似文献   

17.
The ring-opening oligomerization reaction of propylene carbonate in the presence of the tert-butylphenol/KHCO3 initiating system was studied by means of Matrix-Assisted Laser Desorption/Ionization Time of Flight Mass Spectrometry (MALDI-TOF MS) and Electrospray Ionization Time of Flight Mass Spectrometry (ESI-TOF MS). According to the MS spectra obtained, different series of peaks were identified. The MS spectra clearly showed that besides the chain-extension reaction yielding oligomers with all propylene oxide units, the formation of oligomers containing carbonate linkages in the chain, and condensation reaction between the latter two also took place. The structure of the oligomers carrying carbonate linkages was determined by the post-source decay (PSD) MALDI-TOF MS/MS method. Based on the MS results, a mechanism for the oligomerization reaction is proposed.  相似文献   

18.
19.
Saffaj et al. recently criticized our method of monitoring carbon dioxide in human postmortem cardiac gas samples using Headspace-Gas Chromatography–Mass Spectrometry.  相似文献   

20.
合成FullereneC60的新方法   总被引:1,自引:0,他引:1  
C60(Backminsterfullerene)是一种巨型分子组成的纯碳物质.1985年,H.W.Kroto等采用激光辐射蒸发石墨制备出稳定的C60原子簇,提出它是切角多面体的结构.1990年,R.Huffman等合成并分离出稳定的C60和C70簇合物,开辟了球化学的崭新领域。目前,本领域尝试研制一系列的衍生物,并用于轻型高效电池、电子计算机蕊片、燃料、太空火箭推进剂、超级润滑剂和癌症治疗等方面,开辟了C60的广泛的应用前景.  相似文献   

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