理论模拟和实验对照研究幅值扫描ac对离子阱质谱性能的影响

随着离子阱质谱分析技术的广泛应用,离子阱共振激发过程的理论模拟和实验验证对于深入研究离子阱质谱性能具有重要的意义.常见的线性离子阱所使用的共振激发弹出电压ac(alternating current)的设置有两种方式:一种是设定1个很小的恒定值(如1 V0-p),另一种是设定为1个幅值扫描范围.然而,鲜有人对比研究这两...     

Imaging of lipids in human adipose tissue by cluster ion TOF-SIMS

Biopsies of human subcutaneous adipose tissue were taken from healthy donors. Samples were high-pressure frozen, freeze-fractured, and freeze dried. Imaging mass spectrometry of samples was performed in a TOF-SIMS mass spectrometer equipped with a bismuth cluster ion source. Blood vessels, the connective tissue, and adipocytes can be seen in TOF-SIMS images. Blood vessels were found labeled by a high content of sodium ions and potassium ions in their lumen and phosphocholine signal in smooth muscle cells of the vessel wall. The connective tissue showed high signal levels of CN(-) fragments, derived from proteins and nucleic acids. Adipocytes showed high signal levels of phosphocholine and cholesterol ubiquitously in their membranes and diacylglycerols in some membrane sites. The central part of adipocytes showed high levels of triacylglycerols and fatty acids. These results are in accordance to those of biochemical studies; however, a precise spatial localization of lipids in adipocytes is demonstrated with MS imaging.     

Imaging mass spectrometry

Imaging mass spectrometry combines the chemical specificity and parallel detection of mass spectrometry with microscopic imaging capabilities. The ability to simultaneously obtain images from all analytes detected, from atomic to macromolecular ions, allows the analyst to probe the chemical organization of a sample and to correlate this with physical features. The sensitivity of the ionization step, sample preparation, the spatial resolution, and the speed of the technique are all important parameters that affect the type of information obtained. Recently, significant progress has been made in each of these steps for both secondary ion mass spectrometry (SIMS) and matrix-assisted laser desorption/ionization (MALDI) imaging of biological samples. Examples demonstrating localization of proteins in tumors, a reduction of lamellar phospholipids in the region binding two single celled organisms, and sub-cellular distributions of several biomolecules have all contributed to an increasing upsurge in interest in imaging mass spectrometry. Here we review many of the instrumental developments and methodological approaches responsible for this increased interest, compare and contrast the information provided by SIMS and MALDI imaging, and discuss future possibilities.     

深亚微米IC超浅结的SIMS表征

Secondary ion mass spectrometry (SIMS) is a standard technique for characterization of dopant distribution in semiconductor industry. In the ultra-shallow junction (USJ) application, the interested depth scale was extended into the surface transient area of SIMS. There is several improved approach reviewed in this paper that can meet the requirements for the USJ characterization. Sputtering with a low energy primary ion beam incident at a large angle respect to the simple surface normal can effectively minimize the depth of the surface transient area, as well as the length of the profile tail. Oxygen leak can reduce the transient ion yield change, but induces lower depth resolution. Quadrupole SIMS can be used in B profile. As and P profiles, however, need magnetic analyzer with higher mass resolution.     

Multiplexed operation of a micromachined ultrasonic droplet ejector array

A dual-sample ultrasonic droplet ejector array is developed for use as a soft-ionization ion source for multiplexed mass spectrometry (MS). Such a multiplexed ion source aims to reduce MS analysis time for multiple analyte streams, as well as allow for the synchronized ejection of the sample(s) and an internal standard for quantitative results and mass calibration. Multiplexing is achieved at the device level by division of the fluid reservoir and separating the active electrodes of the piezoelectric transducer for isolated application of ultrasonic wave energy to each domain. The transducer is mechanically shaped to further reduce the acoustical crosstalk between the domains. Device design is performed using finite-element analysis simulations and supported by experimental characterization. Isolated ejection of approximately 5 microm diameter water droplets from individual domains in the micromachined droplet ejector array at around 1 MHz frequency is demonstrated by experiments. The proof-of-concept demonstration using a dual-sample device also shows potential for multiplexing with larger numbers of analytes.     

电感耦合等离子体质谱、热电离质谱和二次离子质谱技术在核工业中的新进展

结合实例,回顾并展望了电感耦合等离子体质谱(ICP-MS)、热电离质谱(TIMS)和二次离子质谱(SIMS)技术的应用进展,特别是在核工业领域中的进展。讨论了未来相关质谱技术的发展方向,并指出目前存在的主要问题,探讨了可能的解决方案。     

二次离子质谱在LED外延技术研究中的应用

Epitaxial growth technology of group III-V semiconductors is used in manufacturing light-emitting diodes. Second-ion mass spectrometry, as a high-sensitive technology in analysis of element density-depth profile, is applied to characterize LED structure and comparison of different epitaxial processes. Characterization of multiple-quantum well by SIMS is also introduced.     

离子迁移谱-质谱技术及其在纳米团簇表征中的应用

纳米团簇具有独特的原子构型、电子结构及新颖的光学、电学和催化性能,是材料领域的热点研究对象之一.原子尺度下纳米团簇结构调控的前提是实现纳米团簇的精准表征.近年来,离子迁移谱与质谱联用技术为纳米团簇表征提供了新手段,根据质荷比、截面数据及结构信息,为深入研究团簇制备过程中尺寸和结构的变化规律提供帮助.本文介绍了离子迁移谱...     

SIMS分析含铀微粒同位素比测量条件的初步研究

The isotope ratios of uranium in particles were closely related to the activities performed in nuclear facilities where the particles were collected, so that the determination of ratio is very important in environmental sample analysis for nuclear safeguards. The method based on the use of secondary ion mass spectrometry (SIMS) was presented for the determination of uranium isotopic composition. The parameters of SIMS were studied in the paper, such as contrast aperture(CA)、lence4(L4)、image field(IF)、the accelerated voltage of primary ions and the secondary ions and so on. These parameters are optimized by measuring the standard reference uranium materials (CRM005 CRM200) for improving the measurement accuracy and the precision of uranium isotopic ratio.     

二次离子质谱(SIMS)分析技术及应用进展

二次离子质谱 ( SIMS)比其他表面微区分析方法更灵敏。由于应用了中性原子、液态金属离子、多原子离子和激光一次束 ,后电离技术 ,离子反射型飞行时间质量分析器 ,离子延迟探测技术和计算机图像处理技术等 ,使得新型的 SIMS的一次束能量提高到 Me V,束斑至亚μm,质量分辨率达到 1 5 0 0 0 ,横向和纵向分辨率小于 0 .5μm和 5 nm,探测限为 ng/g,能给出二维和三维图像信息。 SIMS能用于矿物、核物质、陨石和宇宙物质的半定量元素含量和同位素丰度测定 ,能鉴定出高挥发性、热不稳定性的生物大分子 ,能进行横向和纵向剖析 ,能进行单颗粒物、团蔟、聚合物、微电子晶体、生物芯片、生物细胞同位素标记和单核苷酸多肽性分型 ( SNP)测定 ,能观测出含有 2 0 0 0碱基对的脱氧核糖核酸 ( DNA)的准分子离子峰。以SIMS在同位素、颗粒物、大分子、生物等研究领域的应用为重点 ,结合实例 ,对 SIMS仪器和技术进展进行了综述     

Structures,energetics, and dynamics of gas phase ions studied by FTICR and HPMS

Both Fourier transform ion cyclotron resonance mass spectrometry (FTICR‐MS) and high‐pressure mass spectrometry (HPMS) are very powerful tools in the field of gas phase ion chemistry. Many experimental method developments based on FTICR‐MS and HPMS are summarized, including the coupling of a high‐pressure external ion source to a FTICR mass spectrometer, blackbody infrared radiative dissociation (BIRD), coupling laser desorption ionization with HPMS, infrared multiple photon dissociation (IRMPD), radiative association and bimolecular routes to gas phase cluster ion formation. An abundance of thermochemical data, such as proton affinities, gas phase acidities, methyl cation affinities and metal cation affinities, have been obtained. Some of these data are the basis of the standard data listed in the NIST thermochemical databases. Ion–molecule interactions, energetics, reactivities, and structures of molecules have been extensively investigated using the methods developed based on HPMS and FTICR mass spectrometric techniques. © 2009 Wiley Periodicals, Inc., Mass Spec Rev 28:546–585, 2009     

香烟燃烧挥发颗粒物的二次离子质谱分析研究(英文)

在室内气氛中,吸烟释放出的颗粒物是倍受关心的污染源之一。本工作运用高性能静态二次离子质谱（TOF SIMS）实验研究了模拟吸烟释放的气溶胶颗粒物中的有机污染物。证实了其中含有氮杂环化合物和多环芳烃。从而初步表明,二次离子质谱在快速表征室内环境污染物方面具有潜在运用价值。     

Developments in molecular SIMS depth profiling and 3D imaging of biological systems using polyatomic primary ions

In principle mass spectral imaging has enormous potential for discovery applications in biology. The chemical specificity of mass spectrometry combined with spatial analysis capabilities of liquid metal cluster beams and the high yields of polyatomic ion beams should present unprecedented ability to spatially locate molecular chemistry in the 100 nm range. However, although metal cluster ion beams have greatly increased yields in the m/z range up to 1000, they still have to be operated under the static limit and even in most favorable cases maximum yields for molecular species from 1 µm pixels are frequently below 20 counts. However, some very impressive molecular imaging analysis has been accomplished under these conditions. Nevertheless although molecular ions of lipids have been detected and correlation with biology is obtained, signal levels are such that lateral resolution must be sacrificed to provide a sufficient signal to image. To obtain useful spatial resolution detection below 1 µm is almost impossible. Too few ions are generated! The review shows that the application of polyatomic primary ions with their low damage cross‐sections offers hope of a new approach to molecular SIMS imaging by accessing voxels rather than pixels to thereby increase the dynamic signal range in 2D imaging and to extend the analysis to depth profiling and 3D imaging. Recent data on cells and tissue analysis suggest that there is, in consequence, the prospect that a wider chemistry might be accessible within a sub‐micron area and as a function of depth. However, these advances are compromised by the pulsed nature of current ToF‐SIMS instruments. The duty cycle is very low and results in excessive analysis times, and maximum mass resolution is incompatible with maximum spatial resolution. New instrumental directions are described that enable a dc primary beam to be used that promises to be able to take full advantage of all the capabilities of the polyatomic ion beam. Some new data are presented that suggest that the aspirations for these new instruments will be realized. However, although prospects are good, the review highlights the continuing challenges presented by the low ionization efficiency and the complications that arise from matrix effects. © 2010 Wiley Periodicals, Inc., Mass Spec Rev 30:142–174, 2011     

二次离子质谱的一次离子光学系统

二次离子质谱仪作为一种强大的表面分析工具,在表面分析领域有着非常广泛的应用。本文报道了一种用于二次离子质谱仪的一次离子光学系统,它可以对电子轰击电离源产生的一次离子进行有效的加速与聚焦,形成稳定的、能量在0～5kV范围内连续可调的离子束流。同时,该光学系统可以在两种聚焦模式下工作,产生两种不同性能的离子束流。实验结果表明,采用电子轰击电离源作为一次离子源的条件,该离子光学系统能够将离子束聚焦至直径为20μm的束斑,其一次离子束流密度最高可达到503.2mA/cm2,可以实现对一般样品(如材料或生物样品)的表面成分分析。     

飞行时间二次离子质谱在生物材料和生命科学中的应用(下)

随着仪器性能的不断提高,飞行时间二次离子质谱(TOF-SIMS)在材料表面化学分析中起着越来越重要的作用。TOF-SIMS的主要测试功能包括表面质谱、化学成像及深度剖析,本工作对TOF-SIMS的化学成像及深度剖析2种功能在生物材料和生命科学中的应用做了简单综述,重点介绍了TOF-SIMS成像技术在生物芯片制备工艺中的应用和TOF-SIMS成像和深度剖析技术对生物分子在细胞和生物体组织上空间分布的表征方法;另外,对生物样品的低温制备方法,样品表面添加基质以增强信号强度的实验手段,使用团簇一次离子源提高分子二次离子产额和利用对样品损伤小的C60离子源为轰击源做深度剖析等实验做了简单的介绍;最后,对TOF-SIMS在生物生命材料领域的应用做了展望。     

A new experimental setup designed for the investigation of irradiation of nanosystems in the gas phase: a high intensity mass-and-energy selected cluster beam

DIAM (Dispositif d'Irradiation d'Agre?gats Mole?culaires) is a new experimental setup devoted to investigate processes induced by irradiation at the nanoscale. The DIAM apparatus is based on a combination of techniques including a particle beam from high-energy physics, a cluster source from molecular and cluster physics, and mass spectrometry form analytical sciences. In this paper, we will describe the first part of the DIAM apparatus that consists of an ExB double spectrometer connected to a cluster ion source based on a continuous supersonic expansion in the presence of ionizing electrons. This setup produces high intensities of energy-and-mass selected molecular cluster ion beams (1000 s of counts s(-1)). The performance of the instrument will be shown through measurements of 6-8 keV beams of protonated water clusters, (H(2)O)(n)H(+) (n = 0-21) and mixed protonated (or deprotonated) water-pyridine cluster ions: PyrH(+)(H(2)O)(n) (n = 0-15), Pyr(2)H(+) (H(2)O)(n) (n = 0-9), and (Pyr-H)(+) (H(2)O).     

Glycomics and glycoproteomics of viruses: Mass spectrometry applications and insights toward structure–function relationships

The advancement of viral glycomics has paralleled that of the mass spectrometry glycomics toolbox. In some regard the glycoproteins studied have provided the impetus for this advancement. Viral proteins are often highly glycosylated, especially those targeted by the host immune system. Glycosylation tends to be dynamic over time as viruses propagate in host populations leading to increased number of and/or “movement” of glycosylation sites in response to the immune system and other pressures. This relationship can lead to highly glycosylated, difficult to analyze glycoproteins that challenge the capabilities of modern mass spectrometry. In this review, we briefly discuss five general areas where glycosylation is important in the viral niche and how mass spectrometry has been used to reveal key information regarding structure–function relationships between viral glycoproteins and host cells. We describe the recent past and current glycomics toolbox used in these analyses and give examples of how the requirement to analyze these complex glycoproteins has provided the incentive for some advances seen in glycomics mass spectrometry. A general overview of viral glycomics, special cases, mass spectrometry methods and work-flows, informatics and complementary chemical techniques currently used are discussed. © 2020 The Authors. Mass Spectrometry Reviews published by John Wiley & Sons Ltd. Mass Spec Rev     

Cluster secondary ion mass spectrometry of polymers and related materials

Cluster secondary ion mass spectrometry (cluster SIMS) has played a critical role in the characterization of polymeric materials over the last decade, allowing for the ability to obtain spatially resolved surface and in‐depth molecular information from many polymer systems. With the advent of new molecular sources such as , , , and , there are considerable increases in secondary ion signal as compared to more conventional atomic beams (Ar⁺, Cs⁺, or Ga⁺). In addition, compositional depth profiling in organic and polymeric systems is now feasible, without the rapid signal decay that is typically observed under atomic bombardment. The premise behind the success of cluster SIMS is that compared to atomic beams, polyatomic beams tend to cause surface‐localized damage with rapid sputter removal rates, resulting in a system at equilibrium, where the damage created is rapidly removed before it can accumulate. Though this may be partly true, there are actually much more complex chemistries occurring under polyatomic bombardment of organic and polymeric materials, which need to be considered and discussed to better understand and define the important parameters for successful depth profiling. The following presents a review of the current literature on polymer analysis using cluster beams. This review will focus on the surface and in‐depth characterization of polymer samples with cluster sources, but will also discuss the characterization of other relevant organic materials, and basic polymer radiation chemistry. © 2009 Wiley Periodicals, Inc., Mass Spec Rev 29:247–293, 2010     

Atom-probe for FinFET dopant characterization

With the continuous shrinking of transistors and advent of new transistor architectures to keep in pace with Moore's law and ITRS goals, there is a rising interest in multigate 3D-devices like FinFETs where the channel is surrounded by gates on multiple surfaces. The performance of these devices depends on the dimensions and the spatial distribution of dopants in source/drain regions of the device. As a result there is a need for new metrology approach/technique to characterize quantitatively the dopant distribution in these devices with nanometer precision in 3D.In recent years, atom probe tomography (APT) has shown its ability to analyze semiconductor and thin insulator materials effectively with sub-nm resolution in 3D. In this paper we will discuss the methodology used to study FinFET-based structures using APT. Whereas challenges and solutions for sample preparation linked to the limited fin dimensions already have been reported before, we report here an approach to prepare fin structures for APT, which based on their processing history (trenches filled with Si) are in principle invisible in FIB and SEM. Hence alternative solutions in locating and positioning them on the APT-tip are presented. We also report on the use of the atom probe results on FinFETs to understand the role of different dopant implantation angles (10° and 45°) when attempting conformal doping of FinFETs and provide a quantitative comparison with alternative approaches such as 1D secondary ion mass spectrometry (SIMS) and theoretical model values.