计算机辅助质谱解析初级专家系统的设计

文中介绍了质谱解析的基本方法 ,讨论了利用开放式可扩充体系结构 MATL AB语言开发综合性计算机辅助质谱解析初级专家系统的构想和设计思想     

不同Gd:C比对金属富勒烯生成的影响及其质谱研究

研究了不同GdC比对金属富勒烯生成的影响,结果表明随着GdC比例大小不同,对金属富勒烯生成结果的影响也不同.通过激光解析飞行时间质谱(LD-TOFMS)和电喷雾质谱(ESI-MS)分析了提取液的富勒烯组成,得到当GdC为150时,金属富勒烯有最高产率.     

不同Gd∶C比对金属富勒烯生成的影响及其质谱研究

研究了不同 Gd∶ C比对金属富勒烯生成的影响 ,结果表明 :随着 Gd∶ C比例大小不同 ,对金属富勒烯生成结果的影响也不同。通过激光解析飞行时间质谱 (LD- TOFMS)和电喷雾质谱 (ESI- MS)分析了提取液的富勒烯组成 ,得到当 Gd∶ C为 1∶ 5 0时 ,金属富勒烯有最高产率。     

2D NMR对刺五加种子中的一个三萜皂苷进行结构解析

通过质谱、核磁共振谱并结合文献对一个三萜皂苷hederagenin 3-O-β-D-glucuronopyranpside进行结构解析. 通过2D NMR（HMQC、HMBC）对其进行了NMR全归属.
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金属氚化物中^3He的热解析行为初步研究

国内外关于金属中氦行为的热解析研究报道尚不多见，特别是关于高固氦合金材料设计、制备、性能快速评价的研究尤为缺乏。本工作从室温到1273K全程线性升温，采用四极质谱计实时测量的方法，研究金属氚化物中^3He的热解析行为。     

氟代四氢小檗碱的波谱特征与结构解析

对四氢小檗碱的氟取代衍生物（化合物1）的一维、二维核磁共振谱（¹H NMR、¹³C NMR、¹H-¹H COSY、HSQC、HMBC）以及质谱进行了解析和报道,对其所有的NMR谱信号进行了归属,确证了氟取代的位置为12位. 同时讨论了质谱的主要碎片离子的可能的裂解方式. 通过多种波谱技术确证了化合物1的结构.     

新药盐酸洛美利嗪的波谱特征与结构确证

对盐酸洛美利嗪的紫外光谱（UV）、红外光谱（IR）、一维及二维核磁共振谱（¹H NMR、 ¹³C NMR、¹H-¹H COSY、HMQC、HMBC）以及质谱(MS)进行了解析和报道, 对其所有的NMR谱信号进行了归属, 同时讨论了质谱的主要碎片离子的可能的裂解方式和红外特征吸收峰所对应的官能团的振动形式. 通过多种波谱技术确证了盐酸洛美利嗪的结构.     

3-OH克拉霉素及其副产物的谱图解析与结构鉴定

克拉霉素水解得到3-OH克拉霉素,中间反应过程伴随着副产物的生成.利用核磁共振氢谱(1H NMR)、质谱(MS)、红外吸收光谱(IR)等对3-OH克拉霉素及其水解反应中的主要副产物的谱图进行解析和结构鉴定.     

阿扑西林结构确证的谱学研究

对青霉素类抗生素阿扑西林的红外光谱（IR）、紫外光谱（UV）、核磁共振氢谱（¹H NMR）、氢氢相关谱（¹H-¹H COSY）、核磁共振碳谱（¹³C NMR）、DEPT谱、碳氢相关谱（HSQC）、质谱（MS）进行了解析,对其所有的NMR谱信号进行了归属,同时讨论了质谱的主要碎片离子的可能的裂解方式和红外特征吸收峰所对应的官能团的振动形式. 通过多种波谱技术确证了阿扑西林的结构.     

阿立哌唑的谱学研究

对抗精神分裂症新药阿立哌唑的紫外光谱(UV)、红外光谱(IR)、核磁共振谱(NMR)以及质谱(MS)进行了解析。根据该化合物的紫外光谱探讨了其在溶液中的存在形式,讨论了红外光谱的特征吸收峰所对应的官能团的振动形式以及质谱的特征同位素离子峰,利用1H—1H cosy,HSQC,HMBC等二维核磁共振技术推断并确证了该化合物的结构,对NMR谱信号进行了归属,并根据化学位移、偶合常数以及二维相关谱分析了该化合物结构中的10个不同的亚甲基。     

Texture analysis of multiple sclerosis: a comparative study

The difficulty of using magnetic resonance imaging (MRI) to support early diagnosis of multiple sclerosis (MS) stems from the subtle pathological changes in the central nervous system (CNS). In this study, texture analysis was performed on MR images of MS patients and normal controls and a combined set of texture features were explored in order to better discriminate tissues between MS lesions, normal appearing white matter (NAWM) and normal white matter (NWM). Features were extracted from gradient matrix, run-length (RL) matrix, gray level co-occurrence matrix (GLCM), autoregressive (AR) model and wavelet analysis, and were selected based on greatest difference between different tissue types. The results of the combined set of texture features were compared with our previous results of GLCM-based features alone. The results of this study demonstrated that (1) with the combined set of texture features, classification was perfect (100%) between MS lesions and NAWM (or NWM), less successful (88.89%) among the three tissue types and worst (58.33%) between NAWM and NWM; (2) compared with GLCM-based features, the combined set of texture features were better at discriminating MS lesions and NWM, equally good at discriminating MS lesions and NAWM and at all three tissue types, but less effective in classification between NAWM and NWM. This study suggested that texture analysis with the combined set of texture features may be equally good or more advantageous than the commonly used GLCM-based features alone in discriminating MS lesions and NWM/NAWM and in supporting early diagnosis of MS.     

Nonlocal Measure Synchronization in Coupled Bosonic Josephson Junctions

We investigate the measure synchronization （MS） in two coupled bosonic Josephson junctions. By tuning up the coupling between the two dynamical systems, in addition to the normal MS, a nonlocal MS （NLMS） state is observed. Furthermore, with the dynamic stability analysis, we present the exact analytical solution of the transition point to NLMS.     

Laser Ablation Inductively Coupled Plasma Mass Spectrometry: Principles and Applications

Abstract

The application of laser ablation inductively plasma mass spectrometry (LA‐ICP‐MS) to the determination of major, minor, and trace elements as well as isotope‐ratio measurements offers superior technology for direct solid sampling in analytical chemistry. The advantages of LA‐ICP‐MS include direct analysis of solids; no chemical dissolution is necessary, reduced risk of contamination, analysis of small sample mass, and determination of spatial distributions of elemental compositions. This review aims to summarize recent research to apply LA‐ICP‐MS, primarily in the field of environmental chemistry. Experimental systems, fractionation, calibration procedures, figures of merit, and new applications are discussed. Selected applications highlighting LA‐ICP‐MS are presented.     

Analysis of sonolytic degradation products of azo dye Orange G using liquid chromatography-diode array detection-mass spectrometry

In this paper, seven new sonolytic degradation products of Orange G were found and identified using powerful analytical techniques such as liquid chromatography-electrospray ionization mass spectrometry (LC-ESI-MS), tandem mass spectrometry (MS/MS), and liquid chromatography with diode-array detection (LC-DAD). Each technique provided complementary information for the degradation products identification. In order to resolve the MS and MS/MS spectra obtained, the separation conditions were optimized. Among them, Orange G was unambiguously identified based on its abundant [M-H](-) ion, [M+H](+) ion, ultra-violet and visible spectra, retention time, and tandem mass spectrometric analysis compared with an authentic standard. The seven new degradation products were tentatively identified based on ultra-violet and visible spectra, [M-H](-) ions, and tandem mass spectrometry. The neutral losses of SO(2), SO(3), N(2) and H(2)O for MS/MS spectra which appear to be characteristic of the negative ion mode were observed. Based on this by-product identification, a possible multi-step degradation scheme is proposed. The analysis results of degradation products reveal that the degradation mechanism proceeds via reductive cleavage of the azo linkage, as well as intermolecular dehydration and desulfonation due to the powerful oxidizing hydroxyl radicals as well as hydrogen radical.     

GenoMass software: a tool based on electrospray ionization tandem mass spectrometry for characterization and sequencing of oligonucleotide adducts

The analysis of DNA adducts is of importance in understanding DNA damage, and in the last few years mass spectrometry (MS) has emerged as the most comprehensive and versatile tool for routine characterization of modified oligonucleotides. The structural analysis of modified oligonucleotides, although routinely analyzed using mass spectrometry, is followed by a large amount of data, and a significant challenge is to locate the exact position of the adduct by computational spectral interpretation, which still is a bottleneck. In this report, we present an additional feature of the in-house developed GenoMass software, which determines the exact location of an adduct in modified oligonucleotides by connecting tandem mass spectrometry (MS/MS) to a combinatorial isomer library generated in silico for nucleic acids. The performance of this MS/MS approach using GenoMass software was evaluated by MS/MS data interpretation for an unadducted and its corresponding N-acetylaminofluorene (AAF) adducted 17-mer (5'OH-CCT ACC CCT TCC TTG TA-3'OH) oligonucleotide. Further computational screening of this AAF adducted 17-mer oligonucleotide (5'OH-CCT ACC CCT TCC TTG TA-3'OH) from a complex oligonucleotide mixture was performed using GenoMass. Finally, GenoMass was also used to identify the positional isomers of the AAF adducted 15-mer oligonucleotide (5'OH-ATGAACCGGAGGCCC-3'OH). GenoMass is a simple, fast, data interpretation software that uses an in silico constructed library to relate the MS/MS sequencing approach to identify the exact location of adduct on oligonucleotides.     

联用技术应用于生物分子中金属和类金属的形态分析

本文依据最近有关联用技术应用于生物样品中痕量金属和类金属形态分析的报道,扼要介绍高效液相色谱（HPLC）和毛细管电泳（CE）与电感耦合等离子质谱（ICP－MS）和电喷雾离子化质谱（ESI－MS）联用技术在砷、硒和镉等元素的形态分析中的应用。体积排阻色谱（SEC）与ICP－MS在线联用最常用的初步筛选未知试样中大分子化合物的方法。但由于SEC的分辨率差,需要应用另一种色谱法,如离子交换色谱法（IEC）或反相色谱法（RP－HPLC）分离以保证分离信号的纯度。在无标准可利用的情况下,电喷雾串联质谱（ES－MS／MS）是用以表征化合物的最佳手段。毛细管区带电泳（CZE）与ICP－MS联用是形态分析的有用工具。分析中需要注意的问题是避免沾污和防止在分离过程中蛋白质的分解。目前,由于缺少标准和参考物质,联用技术主要应用于寻找新的金属物 种,而并非测定已知化合物。需要解决的难题是检测的信号是否属于某一特定的化合物以及该化合物的表征。     

Full utilization of a mass spectrometer using on-demand sharing with multiple LC units

The applicability of liquid chromatography-mass spectrometry (LC/MS) is often limited by throughput. The sharing of a mass spectrometer with multiple LCs significantly improves throughput; however, the reported systems have not been designed to fully utilize the MS duty cycle, and as a result to achieve maximum throughput. To fully utilize the mass spectrometer, the number of LC units that a MS will need to recruit is application dependent and could be significantly larger than the current commercial or published implementations. For the example of a single analyte, the number may approach the peak capacity to a first degree approximation. Here, the construction of a MS system that flexibly recruits any number of LC units demanded by the application is discussed, followed by the method to port a previously developed LC/MS method to the system to fully utilize a mass spectrometer. To demonstrate the performance and operation, a prototypical MS system of eight LC units was constructed. When 1-min chromatographic separations were performed in parallel on the eight LCs of the system, the average LC/MS analysis time per sample was 10.5 s when applied to the analysis of samples in 384-well plate format. This system has been successfully used to conduct large-volume biochemical assays with the analysis of a variety of molecular entities in support of drug discovery efforts. Allowing the recruitment of the number of LC units appropriate for a given application, this system has the potential to be a plug-and-play system to fully utilize a mass spectrometer. Copyright ? 2012 John Wiley & Sons, Ltd.     

Nanoanalysis of the arthropod neuro-toxins

Many kinds of venomous principles modulate physiological responses of mammalian signal transduction systems, on which they act selectively as enhancers, inhibitors or some other kind of effectors. These toxins become useful tools for physiological research. We have employed and characterized paralyzing toxins from the venom of spiders, insects and scorpions with a limited supply. We have developed rapid and sensitive mass spectrometric technology and applied for the identification of these toxins. Venom profiles are screened by MALDI-TOF fingerprinting analysis prior to purification of venomous components, then marked target toxins of small molecular mass (1000–5000) are characterized directly by means of mass spectrometric techniques such as Frit-FAB MS/MS, CID/PSD-TOF MS, Capil.-HPLC/Q-TOF MS/MS etc.     

硒的化学与生物形态分析综述

硒是人体必需的微量元素，其特殊的生理，生化功能不仅取决于硒的总浓度水平，而且同不同化学生物形态下硒的存在密切相关，硒的分析研究在生命科学、环境科学、医药科学等领域日益活跃。本文就近年来在硒分析方面发表的有关文献，从样品的采集条件，储存条件，消解过程，总量测定，特别是应用各种联用技术进行硒化物形态分析等诸方面，作出较系统全面的综述。