敞开式离子化质谱技术研究进展

军事、公共安全和应急救援等对现场、实时、准确、快速检测技术提出了迫切需求。敞开式离子化质谱技术可以现场直接分析样品,具有简单、快速、无需样品前处理、可分析多种相态物质的特点。本文总结了基于激光、等离子体和电喷雾原理的敞开式离子化技术的研究进展,介绍了敞开式离子化质谱技术在化学战剂、生物和爆炸物检测领域的应用,并对敞开式离子化质谱技术面临的问题和未来研究方向进行了总结与展望。     

基于电喷雾质谱的反应监测研究进展

电喷雾质谱(ESI-MS)因具有灵敏度高、响应速度快、分辨率高、原位在线监测等特点,广泛应用于反应监测领域。本文主要从不同离子化技术角度,综述了电喷雾质谱在反应监测和机理研究方面的进展。重点介绍了在线电喷雾质谱技术,其中包括解吸附电喷雾离子化质谱（DESI-MS）、萃取电喷雾离子化质谱（EESI-MS）、纳升电喷雾离子化质谱（nESI-MS）、超声喷雾离子化质谱（SSI-MS）以及其他在线电喷雾离子化质谱在反应监测中的应用。最后,对电喷雾质谱在反应监测的发展趋势进行总结和展望。     

生物样品中醇类代谢物的化学衍生化质谱分析方法研究进展

生物样品的代谢组学是近年来质谱领域的研究热点。醇类代谢物是生物样品非常重要的一类代谢物,主要包括脂肪醇、糖类、酚类、甘油酯类以及甾醇等。这些代谢物在体内承担着各种重要的生理学功能。然而,由于大多数醇类代谢物极性较低,缺乏易于离子化的基团,其在质谱领域的研究比胺类、酸类等代谢物少。化学衍生化技术通过设计靶向某官能团的有机化学试剂与样品中目标代谢物发生衍生化反应,从而将衍生化试剂基团加载于待测物的分子骨架中。通过衍生化试剂基团的加入,可以改变待测物的理化性质,大幅改善其在质谱中的离子化效率,从而建立快速灵敏的代谢物检测方法。将化学衍生化技术应用于醇类代谢物的质谱检测分析中,能够改善其质谱行为,为醇类代谢物的生理学和病理学研究提供帮助。本综述对近年来报道的醇类代谢物的化学衍生化反应进行整理和归纳,并介绍基于这些衍生化反应开发的针对醇类代谢物的定性定量及快速筛查方法。     

酚醛树脂的质谱分析研究

质谱能快速而准确地给出被测样品分子量的绝对值。普通质谱不能用于高分子聚合物分析的主要原因是高分子的不挥发性利不稳定性，采用软离子化技术可在一定技术程度上克服上述困难。     

DART-Orbitrap质谱法快速筛查饲料中磺胺类药物

利用新型离子化技术--实时直接分析(DART)离子源与高分辨质谱Orbitrap联用,建立饲料中非法添加磺胺类药物的快速筛查方法。通过对DART离子化温度、样品检测模式等参数进行探索优化,最终确定饲料经过乙腈-水溶液简单提取,液体筛网模块进样,450 ℃下离子化,Orbitrap高分辨质谱在全扫描模式下定性检测,并进行相关的方法学验证,方法检出限为1.0~4.0 μg/g。该方法前处理简单、检测速度快、定性准确、样品通量大、环保无污染,能满足饲料中非法添加磺胺类药物快速筛查的要求。     

LC/MS技术在寡核苷酸类药物生物样品定量分析和代谢物鉴定中的应用

寡核苷酸是药物发展的新领域,这类药物是人工合成的DNA或RNA片段,一般由15~50个核苷酸组成,其药动学研究的经典方法是酶联免疫法,但由于该方法的建立耗时、耗资,因此成为新药研发的瓶颈。液相色谱-质谱（LC/MS）联用技术在寡核苷酸类药物生物分析中面临的主要问题有：待测物离子化效率低、基质效应严重、色谱分离条件与质谱不易兼容,样品处理回收率低,但该方法建立快速且选择性强,并能够同时进行代谢产物研究,因此,这项技术尽管存在一些缺点但依然备受关注。本文综述了过去15年中LC/MS技术在寡核苷酸类药物生物样品定量分析和代谢物鉴定中的发展和应用。     

纳结构的连续激光复合微纳探针刻划加工

为了加工形貌稳定且尺寸尽可能小的纳结构,建立了一套连续激光复合微纳探针的加工系统,并研究了光纤探针导光的连续激光辐照微纳探针的近场增强效应以及该系统的加工性能。首先,根据表面等离子体激元理论仿真分析了激光辐照原子力显微镜(AFM)探针的近场增强因子,并研究了微纳探针的针尖温度场和针尖热膨胀。接着,搭建了基于光纤探针导光的连续激光复合微纳探针的纳结构加工系统。最后,对聚乙烯片状材料样品进行了纳结构加工。结果显示:加工得到的纳米点尺度为200nm左右;纳米线的尺度为30~40nm。结果表明:光纤探针导光连续激光复合微纳探针系统避免了复杂的空间光路结构,是一种成本低廉,结构简单的系统,能够实现纳结构的加工。     

质谱直接定量分析技术的应用进展

质谱直接定量分析指待测样品在引入质谱离子源之前,不经色谱分离,直接利用质谱信号对分析物进行含量测定的分析技术。该技术在很大程度上缩短了样品的检测周期,能够满足快速在线、原位分析的需求,目前已在质谱成像、单细胞分析以及在线反应监测等领域展现出广阔的应用前景。本工作综述了与质谱直接定量分析有关的质谱技术、样品处理方法以及相关应用,并展望质谱定量分析的发展趋势。     

高选择性固体基底电喷雾质谱离子源的研究进展

固体基底电喷雾离子源使用固体基底承载样品,并对样品进行电喷雾离子化,是敞开式质谱分析的核心,适用于小分子化合物和生物大分子的快速质谱分析,但是对复杂基质中微量甚至痕量水平目标物的检测灵敏度较低。因此,为提高离子化效率和目标物质的信号响应,优化固体基底电喷雾离子源的选择性是非常必要的。本文首先介绍典型固体基底材料的类型;然后重点介绍提高离子源选择性的策略,包括利用碳基材料、高分子聚合物和免疫材料等对固体基底进行修饰的方法及应用;最后探讨这些方法的优势和问题,以及未来面对的挑战及发展趋势。     

针头喷雾常压离子化质谱技术对化生物质的现场检测研究

近年来常压离子化技术在对特定物质的快速现场质谱检测提供了一条很好的技术途径。本文针对该技术领域,提出了一种新型的针头喷雾常压离子化方法,在离子阱质谱仪上采用化学毒剂模拟剂(DMMP)样品及其与污水的混合液体、Met-Arg-Phe-Ala(MRFA)肽段生物样品进行了喷雾实验,验证了这种新的喷雾方法对复杂样品的直接质谱检测分析性能。实验结果表明,针头喷雾离子化质谱技术能够对MRFA肽段生物样品进行检测,最低检测限为5ng/mL;对DMMP液体样品进行在线直接检测,最低检测限为1ng/mL,检测时间为1.5min。通过与Nano-ESI喷雾离子化方法对比实验,实验结果表明,采用本文方法检测得到的离子流强度是Nano-ESI方法的2倍,同时离子流信号也较稳定,是一种适合战场化生在线快速检测的新型离子化质谱检测技术。     

原位电离小型便携式质谱法现场快速筛查婴幼儿洗护用品中的危害物质

采用原位电离和小型便携式质谱技术建立了婴幼儿洗护用品中危害物质的现场快速筛查方法。将婴幼儿湿巾样品所含液体滴加在三角形色谱纸基上,再滴加萃取喷雾溶剂,采用纸喷雾电离方式进行萃取和电离;牙膏、奶瓶洗涤剂和护臀膏等黏性样品通过金属微电极蘸取样品,插入预先注入萃取喷雾溶剂的毛细管中,采用萃取纳升喷雾电离方式进行萃取和电离。无需繁琐耗时的样品前处理过程,同时结合小型便携式质谱仪,可在1 min内完成样品的现场快速筛查分析,8种目标物质的检出限在10~50 μg/kg之间。该方法简单快速、灵敏高效,适用于婴幼儿洗护用品中危害物质的现场快速筛查。     

激光解吸／电离飞行时间质谱法分析富勒烯

本文介绍激光飞行时间访港测定C60的极高的灵敏度（优于2×10－15mol）、研究了富勒烯在激光辐照下的裂解规律及对富勒烯混合物的分析，展示激光飞行时间质论在分析富勒烯材料方面的优异性能。     

Mass spectrometry imaging under ambient conditions

Mass spectrometry imaging (MSI) has emerged as an important tool in the last decade and it is beginning to show potential to provide new information in many fields owing to its unique ability to acquire molecularly specific images and to provide multiplexed information, without the need for labeling or staining. In MSI, the chemical identity of molecules present on a surface is investigated as a function of spatial distribution. In addition to now standard methods involving MSI in vacuum, recently developed ambient ionization techniques allow MSI to be performed under atmospheric pressure on untreated samples outside the mass spectrometer. Here we review recent developments and applications of MSI emphasizing the ambient ionization techniques of desorption electrospray ionization (DESI), laser ablation electrospray ionization (LAESI), probe electrospray ionization (PESI), desorption atmospheric pressure photoionization (DAPPI), femtosecond laser desorption ionization (fs‐LDI), laser electrospray mass spectrometry (LEMS), infrared laser ablation metastable‐induced chemical ionization (IR‐LAMICI), liquid microjunction surface sampling probe mass spectrometry (LMJ‐SSP MS), nanospray desorption electrospray ionization (nano‐DESI), and plasma sources such as the low temperature plasma (LTP) probe and laser ablation coupled to flowing atmospheric‐pressure afterglow (LA‐FAPA). Included are discussions of some of the features of ambient MSI for example the ability to implement chemical reactions with the goal of providing high abundance ions characteristic of specific compounds of interest and the use of tandem mass spectrometry to either map the distribution of targeted molecules with high specificity or to provide additional MS information on the structural identification of compounds. We also describe the role of bioinformatics in acquiring and interpreting the chemical and spatial information obtained through MSI, especially in biological applications for tissue diagnostic purposes. Finally, we discuss the challenges in ambient MSI and include perspectives on the future of the field. © 2012 Wiley Periodicals, Inc., Mass Spec Rev 32:218–243, 2013     

富勒烯及富勒烯衍生物的质谱研究进展

综述了近 2 0年来富勒烯及其衍生物的质谱研究进展。概述了激光解吸飞行时间质谱 ( LD-TOFMS)、化学电离质谱 ( CIMS)、解吸化学电离质谱 ( DCIMS)、解吸电子轰击质谱 ( DEIMS)、电喷雾电离质谱 ( ESIMS)、傅立叶变换离子回旋共振质谱 ( FT-ICRMS)等质谱技术在富勒烯及其衍生物的表征、生成机理及结构研究、富勒烯气相离子化学及反应活性研究等中发挥的重要作用。由于 C60 等富勒烯及其衍生物的难挥发性及强紫外光吸收能力 ,L D-TOFMS特别适用于富勒烯及其衍生物的分析。结合其它技术 ,LD-TOFMS对富勒烯的生成机理及构型构象异构提供了大量的信息。各种质谱技术与离子化技术结合 ,揭示了不同富勒烯及富勒烯衍生物单分子的解离模式 ,证明了富勒烯的“超芳香性”和“超烯性”等各种反应活性     

喷雾辅助激光解吸离子化质谱法用于奶制品快速鉴定

Spray-assisted laser desorption ionization mass spectrometry(SALDI-MS) was applied to rapid fingerprinting of dairy products for authentication. Unique SALDI-MS fingerprints of three famous Chinese dairy brands were obtained. Counterfeit samples could be rapidly distinguished from the authentic ones. We believe that this sample-preparation-free technique can be a very useful product screening tool in dairy industry because of its sensitivity, simplicity, and high throughput.     

Microorganism characterization by single particle mass spectrometry

In recent years a major effort by several groups has been undertaken to identify bacteria by mass spectrometry at the single cell level. The intent of this review is to highlight the recent progress made in the application of single particle mass spectrometry to the analysis of microorganisms. A large portion of the review highlights improvements in the ionization and mass analysis of bio-aerosols, or particles that contain biologically relevant molecules such as peptides or proteins. While these are not direct applications to bacteria, the results have been central to a progression toward single cell mass spectrometry. Developments in single particle matrix-assisted laser desorption/ionization (MALDI) are summarized. Recent applications of aerosol laser desorption/ionization (LDI) to the analysis of single microorganisms are highlighted. Successful applications of off-line and on-the-fly aerosol MALDI to microorganism detection are discussed. Limitations to current approaches and necessary future achievements are also addressed.     

A Dual Ionization Source with Laser Desorption Sample Introduction in a Time-of-Flight Mass Spectrometer

Abstract

A new mass spectrometric detection system has been developed for the analysis of non-volatile chemical species such as biochemicals. This system involves the use of a novel dual ionization source, consisting of laser-induced electron ionization (EI) and multiphoton ionization (MPI), to provide versatile ionization for a wide range of chemicals in a time-of-flight mass spectrometer. Laser desorption is incorporated into the system for sample vaporization.

The experimental design of this system is described. It is demonstrated that two ionization modes can be interchanged very readily by simply adjusting the position and focus of the laser beam. EI and MPI mass spectra of a number of amino acids and small peptides are shown to illustrate the detection capability of the system. For chemicals amenable to both ionization methods, EI and MPI can provide sensitive detection with different fragmentation patterns. Thus, the operation in a dual ionization mode provides enhanced structural information. In addition, laser-induced EI is shown to be a more general ionization method while MPI provides selective ionization with controlled fragmentation. The combination of these unique properties is demonstrated in the study of laser desorption process of an organic salt.     

Orthogonal acceleration time-of-flight mass spectrometry

The principles and applications of time-of-flight mass spectrometry involving instruments with independent (orthogonal) axes for ion generation and mass analysis are reviewed. This approach, generally referred to as orthogonal acceleration time-of-flight mass spectrometry, has proved particularly advantageous for the combination of continuous ionization sources with time-of-flight mass spectrometry. The history of the technique is briefly discussed along with the instrumental principles pertaining to all the stages of the instrumentation from ion source to detector. The applications of commercial and customized instruments are discussed for several ionization methods including electrospray, matrix assisted laser desorption/ionization, electron ionization, and plasma ionization.     

超分子溶剂萃取-超高效液相色谱-四极杆/静电场轨道阱质谱法测定纺织品中15种有机磷酸酯类阻燃剂

建立了超高效液相色谱-四极杆/静电场轨道阱高分辨质谱法检测纺织品中15种有机磷酸酯类阻燃剂。以正辛醇、四氢呋喃和水形成的超分子溶剂为萃取剂，通过单因素优化结合响应面设计对超分子溶剂组成、用量及超声时间等关键因素进行优化。采用ACQUITY UPLC BEH C18（50 mm×2.1 mm×1.7 μm）色谱柱分离，高分辨质谱一级全扫描结合数据依赖二级质谱模式下的碰撞诱导解离图谱对目标化合物进行筛选鉴别。实验结果表明，15种有机磷酸酯类阻燃剂在各自浓度范围内线性关系良好，相关系数r>0.99，检出限为0.8~16 μg/kg，定量限为2~40 μg/kg。在低、中、高3个添加水平下，15种有机磷酸酯类阻燃剂的平均回收率为81.0%~118.5%，相对标准偏差为2.06%~9.98%（n=6）。该方法稳定快速、准确可靠，可用于纺织品中15种磷酸酯类阻燃剂的测定。