共查询到19条相似文献,搜索用时 46 毫秒
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同位素质谱和无机质谱 总被引:2,自引:0,他引:2
本文是《分析试验室》定期评述中“同位素质谱和无机质谱”的第四篇评述,评述的范围是1994年11月至1996年10月我国气体同位素质谱,热电离同位素质谱,加速器质谱,火花源质谱,电感耦合等离子体质谱,辉光放电质谱,同位素稀释质谱,二次离子质谱,激光共振电离子飞行时间质谱,电子探针,质子探针,激光探针和它们在地学,核科学,环境科学,材料学,计理学,医学和生命科学中的应用,引用文献149篇。 相似文献
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王志恒刘权卫马敬王志强秦永泉 《化学分析计量》2023,(4):102-108
对磁质谱在核科学领域的研究进展进行了综述。介绍了磁质谱的基本原理,详细论述了扇形磁场电感耦合等离子体质谱、加速器质谱、二次离子质谱、热电离质谱、激光共振电离质谱、辉光放电质谱的电离机理、特征及应用领域。扇形磁场电感耦合等离子体质谱分辨率高,检测限低,在元素和同位素分析中应用最为广泛。加速器质谱通常用于样品中超痕量、长寿命放射性核素的量化分析。TI-MS被认为是元素同位素比值分析最精确的仪器之一,而辉光放电质谱主要运用于高纯材料中杂质的分析。 相似文献
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质子转移反应质谱的建立与性能研究 总被引:2,自引:0,他引:2
报道了自行研制的质子转移反应质谱的基本结构和性能。利用水蒸气辉光放电产生了反应离子H3O ,以合成空气为反应气体,测量了H3O 与合成空气中的水反应产生的团簇离子H3O (H2O)n的质谱。实验发现,当漂移管电场与分子密度比值为144Td时,增加的离子能量可以阻止团簇离子H3O (H2O)n的形成,质谱观察到的离子主要是H3O ,其纯度可达99%以上,这时H3O 与有机物分子如甲苯的质子转移反应的产物离子也呈单一形式,团簇离子得到很好地抑制。根据离子强度和离子反应时间等参数,获得了PTR-MS目前的检出限为10-8(V/V)。利用PTR-MS对标准浓度甲苯及其稀释气体进行检测,表明PTR-MS在线定量检测准确性良好,线性动态范围跨越3个数量级,能够应用于大气中痕量挥发性有机物的实时在线测量。 相似文献
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电感耦合等离子体质谱法测定锆及锆合金中镉含量的质谱干扰分析 总被引:2,自引:0,他引:2
通过对Zr及Zr合金中各元素一定浓度单标溶液在电感耦合等离子体质谱(ICP-MS)设定的扫描区间(106~116aum)进行扫描得到质谱图,并结合各元素单标溶液在Cd元素不同同位素质谱峰处的离子计数值的分析,研究了ICP-MS测定Zr及Zr合金中Cd含量时所受的质谱干扰情况,并对干扰物进行了判断。结果表明:基体元素Zr、合金元素Nb和杂质元素Mo所形成的氧化物、氢氧化物多原子离子及合金元素Sn所形成的同质异位素均会对Cd的相关同位素原子构成质谱干扰;针对不同干扰,提出了避免和消除干扰可参考的方法。 相似文献
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充氘钯空心阴极灯中放电气体的质谱研究杨原,王小如(厦门大学化学系,厦门,361005)关键词充氘钯阴极,辉光放电,氦-4质谱钯吸附氢气及氘气的研究已有报道[1],在一定操作条件下,钯吸附氘后还可能产生异常效应[2]。金属空心阴极灯已被广泛地应用于物理... 相似文献
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研制了适合在线气体分析的电晕放电大气压电离源(corona discharge atmospheric pressure ionization source)及其与商品质谱仪(LTQ-MS)的接口,对其试剂离子的产生机理进行了研究,以H2O. (H2O)为试剂离子,对乙醇气体进行检测,并分析了该离子的产生机制。实验结果表明:在潮湿氮气中电晕放电产生的主要试剂离子是m/z36、37和55;而在含丙酮的潮湿氮气中则产生m/z59和76等离子。利用静态顶空-电晕放电大气压电离质谱对不同浓度的乙醇水溶液进行分析,结果表明:以m/z64为检测对象,乙醇气体浓度的最低检出限可达2.4×10-7g/L;而以m/z47为检测对象,检出限为5.9×10-6g/L。同时还利用动态顶空-电晕放电大气压电离质谱对栀子花香气成分进行了检测,为生物挥发性物质的在线检测提供了一种新方法。 相似文献
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Pei Su Hang Hu Daisy Unsihuay Di Zhang Dr. Tiziano Dainese Dr. Rosa E. Diaz Jongsu Lee Dr. Don K. Gunaratne Prof. Haiyan Wang Prof. Flavio Maran Prof. Jianguo Mei Prof. Julia Laskin 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(20):7785-7790
The design of functional interfaces is central to both fundamental and applied research in materials science and energy technology. We introduce a new, broadly applicable technique for the precisely controlled high-throughput preparation of well-defined interfaces containing polyatomic species ranging from small ions to nanocrystals and large protein complexes. The mass-dispersive deposition of ions onto surfaces is achieved using a rotating-wall mass analyzer, a compact device which enables the separation of ions using low voltages and has a theoretically unlimited mass range. We demonstrate an efficient deposition of singly charged Au144(SC4H9)60 ions (33.7 kDa), which opens up exciting opportunities for the structural characterization of nanocrystals and their assemblies using transmission electron microscopy. Our approach also enables the high-throughput deposition of mass-selected ions from multicomponent mixtures, which is of interest to the controlled preparation of surface gradients and rapid screening of molecules in mixtures for a specific property. 相似文献
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Philip Lössl Joost Snijder Albert J. R. Heck 《Journal of the American Society for Mass Spectrometry》2014,25(6):906-917
Over the last two decades, native mass spectrometry (MS) has emerged as a valuable tool to study intact proteins and noncovalent protein complexes. Studied experimental systems range from small-molecule (drug)–protein interactions, to nanomachineries such as the proteasome and ribosome, to even virus assembly. In native MS, ions attain high m/z values, requiring special mass analyzers for their detection. Depending on the particular mass analyzer used, instrumental mass resolution does often decrease at higher m/z but can still be above a couple of thousand at m/z 5000. However, the mass resolving power obtained on charge states of protein complexes in this m/z region is experimentally found to remain well below the inherent instrument resolution of the mass analyzers employed. Here, we inquire into reasons for this discrepancy and ask how native MS would benefit from higher instrumental mass resolution. To answer this question, we discuss advantages and shortcomings of mass analyzers used to study intact biomolecules and biomolecular complexes in their native state, and we review which other factors determine mass resolving power in native MS analyses. Recent examples from the literature are given to illustrate the current status and limitations. Figure
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J. Grotemeyer 《Analytical and bioanalytical chemistry》2003,377(7-8):1097-1097
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Soheil Pourshahian 《Journal of the American Society for Mass Spectrometry》2017,28(9):1836-1843
Mass defect is associated with the binding energy of the nucleus. It is a fundamental property of the nucleus and the principle behind nuclear energy. Mass defect has also entered into the mass spectrometry terminology with the availability of high resolution mass spectrometry and has found application in mass spectral analysis. In this application, isobaric masses are differentiated and identified by their mass defect. What is the relationship between nuclear mass defect and mass defect used in mass spectral analysis, and are they the same? 相似文献
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Dr. Tristan Doussineau Dr. Carole Mathevon Dr. Lucie Altamura Dr. Charlotte Vendrely Dr. Philippe Dugourd Dr. Vincent Forge Dr. Rodolphe Antoine 《Angewandte Chemie (International ed. in English)》2016,55(7):2340-2344
Amyloid fibrils are self‐assembled protein structures with important roles in biology (either pathogenic or physiological), and are attracting increasing interest in nanotechnology. However, because of their high aspect ratio and the presence of some polymorphism, that is, the possibility to adopt various structures, their characterization is challenging and basic information such as their mass is unknown. Here we show that charge‐detection mass spectrometry, recently developed for large self‐assembled systems such as viruses, provides such information in a straightforward manner. 相似文献
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Kaiser NK Quinn JP Blakney GT Hendrickson CL Marshall AG 《Journal of the American Society for Mass Spectrometry》2011,22(8):1343-1351
Fourier transform ion cyclotron resonance (FTICR) mass spectrometry provides unparalleled mass measurement accuracy and resolving
power. However, propagation of the technique into new analytical fields requires continued advances in instrument speed and
sensitivity. Here, we describe a substantial redesign of our custom-built 9.4 tesla FTICR mass spectrometer that improves
sensitivity, acquisition speed, and provides an optimized platform for future instrumentation development. The instrument
was designed around custom vacuum chambers for improved ion optical alignment, minimized distance from the external ion trap
to magnetic field center, and high conductance for effective differential pumping. The length of the transfer optics is 30%
shorter than the prior system, for reduced time-of-flight mass discrimination and increased ion transmission and trapping
efficiency at the ICR cell. The ICR cell, electrical vacuum feedthroughs, and cabling have been improved to reduce the detection
circuit capacitance (and improve detection sensitivity) 2-fold. The design simplifies access to the ICR cell, and the modular
vacuum flange accommodates new ICR cell technology, including linearized excitation, high surface area detection, and tunable
electrostatic trapping potential. 相似文献