适用小分子化合物MALDI分析的基质研究

基质辅助激光解吸电离技术（matrix assisted laser desorption/ionization,MALDI）是20世纪80年代发展起来的一种应用于质谱分析的电离化技术。MALDI技术在生物大分子的分析和检测方面获得了良好的应用。由于受有机基质分子的干扰,MALDI在小分子化合物分析方面的应用受到很大的限制。近年来为解决这一问题,一些用于MALDI分析的新型材料被设计和开发出来。这些新型材料主要包括：碳、硅、纳米金属等无机材料和新型有机分子等。除此之外,在传统基质中添加表面活性剂和对分析物衍生化等方法也被成功应用于小分子化合物的MALDI质谱分析中。本文对这些可应用于小分子化合物分析的新型MALDI基质进行了综述和展望。     

用MALDI-TOF-MS法表征系列环状预聚体

应用基质辅助激光解吸电离飞行时间质谱（MALDI－TOF－MS）技术对系列环状预聚体进行了表征,分别确定了系列环状预聚体各自不同的聚合度,同时对它们的结构进行了确认,获得了满意的结果。实验结果表明MALDI－TOF－MS是分析环状预聚体准确、快速工具之一。     

蛋白质组学中基质辅助激光解吸电离的基质研究进展

基质辅助激光解吸电离(MALDI)技术是近年来发展起来的新的质谱离子化技术。本文较为系统地综述了应用于蛋白质组学中的MALDI基质的最新进展以及不同的基质的优缺点及应用范围,并且归纳了其发展趋势。     

双步激光解析/激光电离质谱法及其应用的新进展

激光光电离技术已广泛应用于质谱领域.基于单束激光的基质辅助激光解析(MALDI)质谱分析方法,已成为质谱分析生物大分子的标准方法之一.本文介绍的是另一种新的激光质谱分析方法:双步激光解析/激光电离质谱法(L2MS),与MALDI相比,该方法不需要加入与样品形成共结晶的基质,同时可通过独立地改变两束激光的光强和波长达到优...     

聚甲基丙烯酸甲酯固定化碳纳米管作为MALDI基质的研究

将聚甲基丙烯酸甲酯材料在多壁碳纳米管表面原位聚合, 利用这种修饰的碳纳米管作为基质辅助激光解析离子化(MALDI)的基质, 利用修饰后的碳纳米管可以“溶解”的特性实现了稳定的MALDI离子化, 并且消除了在低质量端的基质噪音. 此类聚合物衍生的碳纳米管具有相对较好的亲水性表面, 可“溶解”在溶剂中. 此方法适用于有机小分子、多肽、聚合物和蛋白质酶解肽段的质谱分析. 实验表明聚甲基丙烯酸甲酯固定化碳纳米管能有效地吸收和传递激光能量, 可与样品充分地分散混合, 质谱检测背景低, 重现性好, 具有较宽的可测质量范围. 此方法在小分子快速检测和蛋白质组学方面有很大的应用前景.     

过渡金属银配体簇化合物的质谱分析

用基质辅助激光解吸电离飞行时间质谱（MALDI－TOF－MS）测定含有过渡金属银配位的簇类化合物苯乙炔基银的结构及其聚合度,比较了线性（linear)和反射（reflectron)飞行时间普各自的特点,探讨了银^107Ag、^109Ag两种同位素在质谱中的贡献及其表现。     

基质辅助激光解吸电离质谱分析糖类物质

基质辅助激光解吸电离质谱（MALDI-MS）是一种样品无需衍生、图谱解析简单、灵敏度高、快速便捷的分析生物样品结构的方法,已被广泛用于糖类物质的结构分析。此技术与HPLC、糖苷酶外切技术以及各种串联质谱等技术结合使用,可给出糖类物质详细的结构信息。本文介绍了基质辅助激光解吸（MALDI）离子化技术的原理、特点、与飞行时间质量分析器（TOF）联用时的相关技术和裂解方式,以及MALDI-MS在分析糖类物质时选用的基质、样品的制备、糖链碎片分析的方法和在不同糖型分析中的应用,展示了它的发展前景。随着MALDI对糖类物质分析时基质的改进、质谱分辨率的提高、质量检测范围的扩大,MALDI-MS技术必将成为糖类物质分析中强有力的工具。     

MALDI质谱技术在酶活性分析中的应用

酶作为生物催化剂参与很多重要的生理过程,同时也是一类重要的生物分子。酶的活性分析对于疾病诊断和治疗具有重要意义。基质辅助激光解吸电离飞行时间质谱(MALDI-TOF MS)具有操作简单、分析速度快、灵敏度高和易于实现高通量分析的特点,已被广泛用于各种组学研究和生物分子的检测,在酶的检测和活性分析中亦发挥了重要作用。该文综述了国内外利用MALDI-TOF MS分析酶活性和进行药物筛选的策略,总结了各种方法的优缺点,提出了MALDI质谱技术在酶活性分析领域存在的问题和挑战,并对其发展前景进行了展望。     

激光解吸电离质谱新型液相基质研究

选用包括纳米粒子在内的多种基质化合物,构成了多种不同组成的液相基质.以多肽、蛋白、大环寡糖和有机小分子等数种类型化合物为样品,系统地考察了不同液相基质在基质辅助激光解吸电离飞行时间质谱(MALDI-TOF)分析中的应用情况,探讨了与固体制样方法的异同点.实验结果表明,有些液相基质对多类化合物具有较好的通用性,而有些液相基质对某些特定类型化合物的分析特别有效.     

用MALDI-TOFMS观察适配子与炭疽芽孢的结合反应

用基质辅助激光解吸电离－飞行时间质谱（MALDI－TOF MS）观察炭疽芽孢适配子与炭疽芽孢结合反应，将SELEX（system evolution of ligands by exponential enrichment）技术筛选获得的一个炭疽芽孢适配子F77和第18轮的混合适配子以及兔抗炭疽芽孢抗体分别与炭疽芽孢结合反应后，用MALDI－TOF MS指纹图变化来研究这些分子与芽孢的结合情况，结果显示抗体、单体和混合适配子与芽孢结合反应后约在m/z1800处产生的质谱峰强度与芽孢对照相比明显降低；用MALDI－TOF MS质谱图变化可以推测适配子与芽孢的结合反应，该试验中观察到的结合情况与作者以前的研究结果一致。     

Technological Advancements in Mass Spectrometry and Its Impact on Proteomics

Amalgamation of mass spectrometry (MS) and proteomics has led to the most awaited technological inventions such as discovery of clinically potential biomarkers and generation of effective drugs. This review focuses on the synergistic growth in MS instrumentation, proteomics and its impact on biomedical sciences. Novel ionization methods: surface enhanced laser desorption ionization, electrospray assisted laser desorption ionization, desorption electrospray ionization, laser diode thermal desorption are discussed. Different mass analyzers: ion trap, time-of-flight, Fourier transform ion cyclotron resonance and their applications are outlined. New ion fragmentation techniques: electron capture dissociation, electron transfer dissociation, infrared multiphoton dissociation and their attributes are described.     

MALDI‐FT‐ICR‐MS for archaeological lipid residue analysis

Soft‐ionization methods are currently at the forefront of developing novel methods for analysing degraded archaeological organic residues. Here, we present little‐used soft ionization method of matrix assisted laser desorption/ionization‐Fourier transform‐ion cyclotron resonance‐mass spectrometry (MALDI‐FT‐ICR‐MS) for the identification of archaeological lipid residues. It is a high‐resolution and sensitive method with low limits of detection capable of identifying lipid compounds in small concentrations, thus providing a highly potential new technique for the analysis of degraded lipid components. A thorough methodology development for analysing cooked and degraded food remains from ceramic vessels was carried out, and the most efficient sample preparation protocol is described. The identified components, also controlled by independent parallel analysis by gas chromatography‐mass spectrometry (GC‐MS) and gas chromatography‐combustion‐isotope ratio mass spectrometry (GC‐C‐IRMS), demonstrate its capability of identifying very different food residues including dairy, adipose fats as well as lipids of aquatic origin. The results obtained from experimentally cooked and original archaeological samples prove the suitability of MALDI‐FT‐ICR‐MS for analysing archaeological organic residues. Sample preparation protocol and identification of compounds provide future reference for analysing various aged and degraded lipid residues in different organic and mineral matrices.     

Elucidating molecular level impact of peat fire on soil organic matter by laser desorption ionization Fourier transform ion cyclotron resonance mass spectrometry

Analytical and Bioanalytical Chemistry - In this work, laser desorption ionization coupled with Fourier transform ion cyclotron resonance mass spectrometry (LDI–FTICRMS) was used to...     

Understanding of the structure, bonding, formation and decomposition of metalloid aluminum clusters--a Fourier transform ion cyclotron resonance study of solid AlCp*

The investigation of the tetrahedral Al4Cp*4 cluster with Fourier transform ion cyclotron resonance mass spectrometry using laser desorption /ionization as the ionization method results in a couple of aluminum cluster compounds AlxCp*+y (x > y) with up to eight aluminum atoms. MS(n) experiments are performed in order to understand the formation and reactivity of the different species. Quantum chemical calculations of the structure and energy for all compounds identified complete this study.     

Binding of alpha 1-acid glycoprotein with aconitum alkaloids: an investigation using an intensity fading matrix-assisted laser desorption/ionization Fourier transform mass spectrometry method

Intensity fading matrix-assisted laser desorption/ionization (IF-MALDI) mass spectrometry has become an alternative screening approach for the affinity-binding analysis of proteins and peptides with ligands. In this study, an attempt has been made to study the interaction of alpha 1-acid glycoprotein (AGP) with aconitum alkaloids by IF-MALDI Fourier transform ion cyclotron resonance mass spectrometry (IF-MALDI-FT-MS). Compared with the nonbinding internal standard, clear reduction in the ion abundances of the target alkaloids was observed with the addition of AGP. Relative binding affinities of different alkaloids towards the protein could also be estimated using IF-MALDI-FT-MS. The binding affinity was also investigated by using ultrafiltration liquid chromatography with photodiode array detection coupled to electrospray ionization mass spectrometry (ultrafiltration LC-DAD/ESI-MS), and results were consistent with that of IF-MALDI-FT-MS.     

High-throughput one-bead-one-compound approach to peptide-encoded combinatorial libraries: MALDI-MS analysis of single TentaGel beads

The identification of pharmacologically promising compounds (lead compounds) from combinatorial libraries is frequently limited by the throughput of the analytical technique employed. Fourier transform mass spectrometry (FTMS) offers high sensitivity, mass accuracy (m/Deltam > 500 000), and sequencing capabilities. A rapid and efficient method for high-throughput analysis of single beads from peptide-encoded combinatorial libraries with matrix-assisted laser desorption/ionization (MALDI) mass spectrometry is presented. Encoding peptides on single beads are identified and structurally characterized by MALDI time-of-flight (TOF) and ultrahigh-resolution MALDI Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometry. A strategy of on-probe sample preparation is developed to minimize handling of the beads.     

Characterization of non-polar aromatic hydrocarbons in crude oil using atmospheric pressure laser ionization and Fourier transform ion cyclotron resonance mass spectrometry (APLI FT-ICR MS)

We report on the successful application of the recently introduced atmospheric pressure laser ionization (APLI) method as a novel tool for the analysis of crude oil and its components. Using Fourier transform ion cyclotron resonance mass spectrometry, unambiguous determination of key compounds in this complex matrix with unprecedented sensitivity is presented.     

2,5‐Dihydroxybenzoic acid solution in MALDI‐MS: ageing and use for mass calibration

2,5‐Dihydroxybenzoic acid (DHB) is one of the most widely used and studied matrix compounds in matrix‐assisted laser desorption/ionization (MALDI) mass spectrometry. However, the influence of ageing of the DHB solution on the MALDI mass spectra has not been yet systematically studied. In this work, the possible changes occurring in the acidified acetonitrile/water solution of the MALDI matrix compound DHB during 1‐year usage period have been monitored with MALDI‐Fourier transform ion cyclotron resonance mass spectrometer (MALDI‐FT‐ICR‐MS) and attenuated total reflectance Fourier transform infrared (ATR‐FT‐IR) spectroscopy. No significant ageing products have been detected. The ability of the aged DHB solution to act as a MALDI matrix was tested with two materials widely used in art and conservation – bone glue (a proteinaceous material) and shellac resin (a resinous material) – and good results were obtained. A number of peaks in the mass spectra measured from the DHB solution were identified, which can be used for internal calibration of the mass axis. Copyright © 2014 John Wiley & Sons, Ltd.     

Analysis of cigarette smoke by laser desorption mass spectrometry

Laser desorption ionization Fourier transform ion cyclotron mass spectrometry (LDI–FTICRMS) has been successfully applied for the characterization of tobacco smokes. The versatily of analysis allows inorganic and organic tobacco smoke constituents to be identified. As a function of ion detection mode and laser irradiance experimental conditions, inorganic nitrate and sulfate as well as nicotine and associated nicotine, tobacco-specific nitrosamine, polycyclic aromatic hydrocarbon, polyoxygenated compounds are highlighted. The high mass resolution and the high mass accuracy attained by LDI–FTICRMS measurements allow the unambiguous assignment of detected species for m/z < 250 to be achieved.