Advances 0n Analysis of Triacylglycerols in Edible Oil Based on Mass Spectrometric Method

该文对质谱鉴定技术及其与色谱联用的分析方法(包括直接进样质谱分析、气相色谱质谱联用技术、超临界流体与质谱联用技术和液相色谱质谱联用技术)在甘油三酯分析方面的应用进行了综述,评述了各类分析方法的优缺点,对常用的脂质分析数据库进行了介绍,并对甘油三酯分析方法的发展及应用作了展望.     

质谱技术在反应监测中的发展和应用

质谱因具有分辨率高、 灵敏度好、 响应快速以及结构鉴定能力强等特点, 近年来在反应监测研究领域应用广泛. 本文介绍了基于质谱的经典在线直接采样实时监测方案; 综合评述了常压质谱离子化技术在反应监测领域的发展和应用, 主要包括基于常压质谱的快反应监测、 微滴加速在长时间反应研究中的应用, 以及其它常压质谱在反应监测中的应用; 并对质谱在反应监测研究领域面临的挑战和发展趋势进行了总结和展望.     

新型污染物的环境质谱技术研究进展

随着科学技术的飞速发展,质谱检测及其联用技术方法正以前所未有的速度、广度和深度全面渗透到环境分析化学中,其在环境监测中的使用已经或正在日常化.近年来,一些高分辨质谱及其与色谱等的联用技术在目标污染物和非目标污染物的同时甄别鉴定和分析中发挥了重要作用,其对于阐明污染物在环境的归趋具有重要意义.本文对质谱技术及其与气相色谱和液相色谱的联用技术在污染物尤其是新型污染物分析中的进展进行了总结,并对高分辨质谱技术的环境应用研究给于关注,对环境质谱技术的发展方向进行了展望.     

食用油甘油三酯质谱分析方法的研究进展

该文对质谱鉴定技术及其与色谱联用的分析方法(包括直接进样质谱分析、气相色谱质谱联用技术、超临界流体与质谱联用技术和液相色谱质谱联用技术)在甘油三酯分析方面的应用进行了综述,评述了各类分析方法的优缺点,对常用的脂质分析数据库进行了介绍,并对甘油三酯分析方法的发展及应用作了展望。     

质谱在高通量快速检测技术中的应用研究进展

质谱是现代分析测试技术中同时具备了灵敏度高、特异性好、分析速度快等特性的普适性方法,现已被广泛应用于食品检验、环境监测、药物筛选、临床医学等众多领域的高通量快速检测技术中。该文针对近年来低分辨质谱、高分辨质谱以及原位电离质谱技术在高通量快速检测,特别是小分子化合物的高通量快速检测中的应用研究进展进行了综述,并对质谱技术用于高通量快速检测的发展趋势及应用前景进行了展望,以期为相关领域的科技人员提供理论支持和技术参考。     

离子阱颗粒质谱研究进展

随着质谱技术的不断发展,对超高质量颗粒物质的分析已经成为质谱领域研究的一个重要方向.离子阱颗粒质谱(particle ion trap mass spectrometry)作为用于完整颗粒质量分析的有利工具,拓展了质谱技术在巨大颗粒物质量分析中的应用范围.本文对离子阱颗粒质谱仪器的研究进展及其在各个领域的应用进行了综述,并展望了离子阱颗粒质谱未来的发展趋势.     

有机化学反应中间体的质谱分析

有机化学反应中活性中间体的性质各异,对反应中间体的表征和研究对于阐明和确证反应机理、优化反应条件、筛选催化剂和发现新类型反应至关重要.近年来,质谱技术和在线微量采样技术的发展,极大程度地拓展了质谱学在该领域的应用.本文总结了近年来本领域发展的新策略、技术和方法,以及有机质谱技术在反应中间体研究中的应用.     

复杂样品质谱分析技术的原理与应用

原位、实时、在线、非破坏、高通量、低耗损的质谱学方法是质谱分析技术发展的重要趋势.在无需样品预处理的条件下对复杂基体样品中痕量待测物直接离子化技术的出现,极大地提高了质谱分析的效率,使实际样品的快速质谱分析成为可能.本文着重综述了能够在无需样品预处理情况下对复杂基体样品离子化的新兴质谱技术及其应用研究,系统阐述了直接离子化技术的基本原理和方法,介绍了几种典型的常压直接离子化技术和装置,对直接离子化质谱分析技术在食品、药品、环境、活体分析、代谢组学、蛋白质组学以及生物组织质谱成像等领域的典型应用进行了述评,讨论了提高复杂样品快速质谱分析选择性的可能方法,并展望了常压直接离子化技术未来发展的可能趋势.     

质谱技术在核酸研究领域的应用

质谱技术具有快速、准确、灵敏度高等优点,近年来在生物分析方面得到了广泛的应用.核酸作为生命的基本物质,一直是生命领域的研究热点,进展日新月异.而质谱方法也成为了科学家研究核酸的强有力工具,具有广阔的发展前景.本文介绍了核酸检测的质谱技术,并简要综述了质谱在核酸的高级结构研究、与小分子相互作用、DNA损伤与修饰等领域的应用,重点介绍了中国学者的研究成果.     

质谱成像分析技术、方法与应用进展

质谱成像技术作为分子成像及质谱领域的研究前沿和热点,近几年受到高度关注并得到迅速发展.本文针对质谱成像技术、方法及其应用的新进展进行了综述与展望,介绍了中国学者近几年在质谱成像分析新技术及其应用方面取得的重要进展.     

Phoenix mars mission—The thermal evolved gas analyzer

The Phoenix spacecraft that was launched to Mars in August 2007 landed safely on the Martian northern arctic region on May 25, 2008. It carried six experiments to study the history of water on the planet and search for organic molecules in the icy subsurface Martian soil. The spacecraft is a lander with an arm and scoop designed to dig a trench though the top soil to reach an expected ice layer near the surface. One of the instruments on board is the thermal evolved gas analyzer (TEGA), which consists of two components, a set of eight very small ovens that will heat samples of the ice soil mixtures from the trench to release imbedded gases and mineral decomposition products, and a mass spectrometer that serves as the analysis tool for the evolved gases, and also for measurements of the composition and isotopic ratios of the gases that comprise the atmosphere of Mars. The mass spectrometer is a miniature magnetic sector instrument controlled by microprocessor-driven power supplies. One feature is the gas enrichment cell that will increase the partial pressures of the noble gases in an atmosphere sample by removing all the active gases, carbon dioxide, and nitrogen, to improve the accuracy of their isotopic ratio measurements.     

Microchip capillary electrophoresis instrumentation for in situ analysis in the search for extraterrestrial life

The search for signs of life on extraterrestrial planetary bodies is among NASA's top priorities in Solar System exploration. The associated pursuit of organics and biomolecules as evidence of past or present life demands in situ investigations of planetary bodies for which sample return missions are neither practical nor affordable. These in situ studies require instrumentation capable of sensitive chemical analyses of complex mixtures including a broad range of organic molecules. Instrumentation must also be capable of autonomous operation aboard a robotically controlled vehicle that collects data and transmits it back to Earth. Microchip capillary electrophoresis (μCE) coupled to laser-induced fluorescence (LIF) detection provides this required sensitivity and targets a wide range of relevant organics while offering low mass, volume, and power requirements. Thus, this technology would be ideally suited for in situ studies of astrobiology targets, such as Mars, Europa, Enceladus, and Titan. In this review, we introduce the characteristics of these planetary bodies that make them compelling destinations for extraterrestrial astrobiological studies, and the principal groups of organics of interest associated with each. And although the technology we describe here was first developed specifically for proposed studies of Mars, by summarizing its evolution over the past decade, we demonstrate how μCE-LIF instrumentation has become an ideal candidate for missions of exploration to all of these nearby worlds in our Solar System.     

Doubly-charged ions in the planetary ionospheres: a review

This paper presents a review of the current knowledge on the doubly-charged atomic and molecular positive ions in the planetary atmospheres of the Solar System. It is focused on the terrestrial planets which have a dense atmosphere of N(2) or CO(2), i.e. Venus, the Earth and Mars, but also includes Titan, the largest satellite of Saturn, which has a dense atmosphere composed mainly of N(2) and a few percent of methane. Given the composition of these neutral atmospheres, the following species are considered: C(++), N(++), O(++), CH(4)(++), CO(++), N(2)(++), NO(++), O(2)(++), Ar(++) and CO(2)(++). We first discuss the status of their detection in the atmospheres of planets. Then, we provide a comprehensive review of their complex and original photochemistry, production and loss processes. Synthesis tables are provided for those ions, while a discussion on individual species is also provided. Methods for detecting doubly-charged ions in planetary atmospheres are presented, namely with mass-spectrometry, remote sensing and fine plasma density measurements. A section covers some original applications, like the possible effect of the presence of doubly-charged ions on the escape of an atmosphere, which is a key topic of ongoing planetary exploration, related to the evolution of a planet. The results of models, displayed in a comparative way for Venus, Earth, Mars and Titan, are discussed, as they can predict the presence of doubly-charged ions and will certainly trigger new investigations. Finally we give our view concerning next steps, challenges and needs for future studies, hoping that new scientific results will be achieved in the coming years and feed the necessary interdisciplinary exchanges amongst different scientific communities.     

Raman spectroscopic analysis of arctic nodules: relevance to the astrobiological exploration of Mars

The discovery of small, spherical nodules termed ‘blueberries’ in Gusev Crater on Mars, by the NASA rover Opportunity has given rise to much debate on account of their interesting and novel morphology. A terrestrial analogue in the form of spherical nodules of similar size and morphology has been analysed using Raman spectroscopy; the mineralogical composition has been determined and evidence found for the biological colonisation of these nodules from the spectral signatures of cyanobacterial protective biochemical residues such as scytonemin, carotenoids, phycocyanins and xanthophylls. This is an important result for the recognition of future sites for the planned astrobiological exploration of planetary surfaces using remote robotic instrumentation in the search for extinct and extant life biosignatures and for the expansion of putative terrestrial Mars analogue geological niches and morphologies.     

Use of the vacuum ultraviolet spectral region for laser-induced breakdown spectroscopy-based Martian geology and exploration

Several elements important to planetary geology (e.g. Br, C, Cl, P, S) and the human exploration of Mars (e.g. toxic elements such as As) have strong emission lines in the purge and vacuum ultraviolet (VUV) spectral region (100–200 nm). This spectral region has not been extensively studied for space applications using geological samples. We studied emissions from the laser-induced breakdown spectroscopy (LIBS) plasma in this region using a sample chamber filled with 7 torr (930 Pa) of CO₂ to simulate the Martian atmosphere. Pressures down to 0.02 torr were also used to evaluate the effect of the residual CO₂ on the spectra and to begin investigating the use of VUV-LIBS for airless bodies such as asteroids and the Moon. Spectra were recorded using a 0.3-m vacuum spectrometer with an intensified CCD (ICCD) camera. The effects of time delay and laser energy on LIBS detection at reduced pressure were examined. The effect of ambient CO₂ on the detection of C in soil was also evaluated. Lines useful for the spectrochemical analysis of As, Br, C, Cl, P, and S were determined and calibration curves were prepared for these elements. Although LIBS is being developed for stand-off analysis at many meters distance, the experiments reported here were aimed at in-situ (close-up) analysis.     

Raman spectroscopy in astrobiology

Raman spectroscopy is proposed as a valuable analytical technique for planetary exploration because it is sensitive to organic and inorganic compounds and able to unambiguously identify key spectral markers in a mixture of biological and geological components; furthermore, sample manipulation is not required and any size of sample can be studied without chemical or mechanical pretreatment. NASA and ESA are considering the adoption of miniaturised Raman spectrometers for inclusion in suites of analytical instrumentation to be placed on robotic landers on Mars in the near future to search for extinct or extant life signals. In this paper we review the advantages and limitations of Raman spectroscopy for the analysis of complex specimens with relevance to the detection of bio- and geomarkers in extremophilic organisms which are considered to be terrestrial analogues of possible extraterrestial life that could have developed on planetary surfaces.     

Evaluation of portable Raman instrumentation for identification of β-carotene and mellitic acid in two-component mixtures with halite

Recently, portable Raman instrumentation has been in demand for geosciences and for future planetary exploration for the identification of both organic and inorganic compounds in situ on Earth and on other planetary bodies, especially on Mars. Here we present the results of the analysis of halite/β-carotene and halite/mellitic acid mixtures, performed by miniaturized Raman instrumentation equipped with 785 and 1064 nm excitation. Various proportions of organics in the halite matrix were examined. The lowest concentration of β-carotene detected using the 785 nm laser was 1 mg kg(-1), with slightly better signals observed with shorter exposure times compared with the bench instrument using the same excitation wavelength. Mellitic acid was identified at the concentration level 10 g kg(-1). The 1064 nm excitation provided a lower sensitivity towards low concentration when compared with the 785 nm excitation.     

Laser-Induced Breakdown Spectroscopy for Mars surface analysis: capabilities at stand-off distances and detection of chlorine and sulfur elements

An international consortium is studying the feasibility of performing in situ geochemical analysis of Mars soils and rocks at stand-off distances up to several meters using the Laser-Induced Breakdown Spectroscopy (LIBS) technique. Stand-off analysis for Martian exploration imposes particular requirements on instrumentation, and it is necessary to first test the performance of such a system in the laboratory. In this paper, we test the capabilities of two different experimental setups. The first one is dedicated to the qualitative analysis of metals and rocks at distances between 3 and 12 m. With the second one, we have obtained quantitative results for aluminum alloys and developed a spectral database under Martian conditions for sulfur and chlorine, two elements that are geologically interesting but generally difficult to detect by LIBS under standard conditions (atmospheric pressure, close distance). These studies were carried out to determine an optimal instrumental design for in situ Mars analysis. The quality of analytical results affected by the optical elements and spectrometer has been particularly highlighted.     

Strategies for Mars remote Laser-Induced Breakdown Spectroscopy analysis of sulfur in geological samples

The key to understanding the sulfur history on Mars is to identify and determine sulfate and sulfide compositions and then to draw from them geologic clues about their environments of formation. To lay a foundation for use of remote LIBS to sulfur analysis in planetary exploration, we have undertaken a focused study of sulfur LIBS in geological samples in a simulated Mars atmosphere, with experimental parameters replicating the ChemCam LIBS instrument. A suite of twelve samples was selected, including rocks rich in minerals representative of sulfates and sulfides that might be encountered on Mars. Univariate analysis of sulfur emission lines did not provide quantitative information. Partial least squares (PLS) analysis was successful at modeling sulfur concentrations for a subset of samples with similar matrices. Sulfide minerals were identified on the basis of other siderophile or chalcophile peaks, such as those arising from Zn and Cu. Because the S lines are very weak compared to those of other elements, optimal PLS results were obtained by restricting the wavelength range to channels close to the most intense sulfur lines ~ 540-570 nm. Principal components analysis was attempted on the dataset, but did not differentiate the samples into meaningful groups because the sulfur lines are not strong enough. However, areas of the relatively weak S, H, and O peaks may be used to correctly classify all samples. Based on these outcomes, a flowchart that outlines a possible decision tree for identification and quantification of sulfur in remote LIBS analysis was constructed. Results suggest that LIBS data acquired under Mars conditions can meet the science requirements for the ChemCam instrument.     

New angle rotor coil planet centrifuge for counter-current chromatography. I. Analysis of acceleration

Simple mathematical analysis has been performed on a new type of synchronous planetary motion to elucidate the acceleration field. Using generalized formulae derived from the above analysis, distribution of the centrifugal force vectors produced by all types of the synchronous planetary motion is computed and expressed in the same format to facilitate comparative studies. The results of the above analysis predict high performance of the new angle rotor coil planet centrifuge in counter-current chromatography.