Multidirmensional gas chromatography – isotope ratio mass spectrometry (MDGC-IRMS). Part A: System description and technical requirements

A system is presented which combines multidimensional GC with isotope ratio mass spectrometry. The performance of the system is demonstrated with an application from the field of flavor analysis. Potentials and limitations of the technique are also discussed.     

浊点萃取在痕量金属元素分析中的应用

浊点萃取(CPE)法是一种新兴的环保型液_液萃取技术，可以作为痕量金属元素的预富集方法。此文总结了CPE法在痕量金属元素分析中应用原理、方法及试验条件优化，概括了CPE作为预富集法在不同分析检测仪器中的应用，探讨了该技术方法的应用前景。     

The Determination of Arsenic in Soil and Sediment Digests by Graphite Furnace Atomic Absorption Spectrometry

Abstract

A method for the determination of As in siliceous materials from a fluoboric acid matrix by GFAAS is described. The basic analytical procedure also permits the measurement of major, minor and other trace elements by flame or graphite furnace AAS as appropriate. For As analysis, the incorporation of matrix modification with Ni and of corrective measures to overcome interference by Al, Na and Si are discussed. The validity of the method is demonstrated by the accurate analysis of four international standard reference materials and agreement with instrumental neutron activation analysis results for As in environmental samples. One application to the study of As geochemistry in lacustrine sediments is presented.     

傅里叶变换离子回旋共振质谱仪:过去、现在与未来

对傅里叶变换离子回旋共振高分辨率质谱仪的发展历程、串联质谱解离技术及最新的应用进行了详细描述,并对其发展趋势进行了展望。     

Chip‐Based Free‐Flow Electrophoresis with Integrated Nanospray Mass‐Spectrometry

Free‐flow electrophoresis is an ideal tool for preparative separations in continuous microflow. With the approach presented herein for coupling free‐flow electrophoresis and mass spectrometry it is now also possible to trace non‐fluorescent compounds and identify them by means of mass spectrometry. The functionality of the method and its potential as an integrated separation unit for microflow synthesis is demonstrated by application to a multicomponent [3+2]‐cycloannulation.     

New approaches to molecular spectroscopic detection in flow-injection analysis

A state-of-the-art overview of molecular spectroscopy as applied in flow injection analysis (FIA) is presented. It deals chiefly with the most interesting FIA approaches aimed at improving detector performance, innovations in the detection system itself and the coupling of FIA with unusual detectors for this technique. The most salient trends in relation to this association are also commented upon.     

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.     

Polarization fourier transform infrared spectroscopy

Some Fourier transform infrared spectroscopic studies with linearly and circularly polarized radiation are reported. They were all carried out by means of the differential technique, consisting in the comparison of two single-channel spectra of opposite polarization. Thus, linear dichroic or circular dichroic spectra with positive and negative bands were recorded. Typical application examples of both techniques are presented.     

激光原子荧光光谱分析法的进展

概述了激光原子荧光光谱分析法的研究现状和发展趋势。对各种原子化学方法与激光原子荧光光谱分析法相结合的分析特性进行了描述，着重介绍了电热原子化作为原子化器的激光原子荧光光谱法近年来的发展和应用。     

Recent trends in atomic spectrometry with microwave-induced plasmas

The state-of-the-art and trends of development in atomic spectrometry with microwave-induced plasmas (MIPs) since the 1998s are presented and discussed. This includes developments in devices for producing microwave plasma discharges, with reference also to miniaturized systems as well as to progress in sample introduction for microwave-induced plasmas, such as pneumatic and ultrasonic nebulization using membrane desolvation, to the further development of gaseous analyte species generation systems and to both spark and laser ablation (LA). The features of microwave-induced plasma mass spectrometry (MIP-MS) as an alternative to inductively coupled plasma (ICP)-MS are discussed. Recent work on the use of microwave-induced plasma atomic spectrometry for trace element determinations and monitoring, their use as tandem sources and for particle sizing are discussed. Recent applications of the coupling of gas chromatography and MIP atomic spectrometry for the determination of organometallic compounds of heavy metals such as Pb, Hg, Se and Sn are reviewed and the possibilities of trapping for sensitivity enhancement, as required for many applications especially in environmental work, are showed at the hand of citations from the recent literature.     

Chemical species produced in the reaction between ethanedial (glyoxal) and 5-amino-1,10-phenanthroline and their iron(II) complexes: preparation and some spectrometric studies

Chemical species obtained by reaction of 5-amino-1, 10-phenanthroline with ethanedial (glyoxal) are reported with regard to their preparation, chemical composition and spectrometric characterization (UV-visible, infrared and liquid secondary ion mass spectrometry). Products of the reaction are postulated to be a mixture of species with molecular weights of 339, 371,480 and 524 u. Chemical reactions leading to these products and possible structural formulas for each of these species are presented. The iron complexes of these ligands, because of their extremely low solubility in most solvents, find application as redox mediators when incorporated in carbon paste electrodes, particularly for sensing in continuous-flow systems.     

A REVIEW OF HYPHENATED CHROMATOGRAPHIC INSTRUMENTATION

Samples presented for chemical analysis are invariably mixtures, often very complex mixtures. This has led to the widespread acceptance and application of what have become called hyphenated chromatographic techniques. These techniques are combinations of chromatographic instrumentation with some (usually) spectroscopic technique. In this review, we treat the most important and useful of these combinations. The basic instrumental features of each method are described, and possible applications are discussed. The relative capabilities of each technique are weighed, and tradeoffs are discussed. In closing, a list of suggested further reading is provided.     

Fluorinated surfactants: synthesis, properties, effluent treatment

Fluorinated surfactants and synthetic fire fighting foams are presented. The fluorinated part of those surfactants can be obtained industrially either by electrofluorination or by telomerization. The fact that fluorine atoms are present in a surfactant molecule modifies its behaviour compared to classical surfactants. It gives to the molecule outstanding chemical and thermal stabilities. Fluorine also produces in these surfactants very low surface tension in aqueous solution even when used at reduced concentrations.For those reasons, it is shown that fluorinated surfactants are particularly adapted to the formulation of film forming fire fighting foams in which they are associated to classical hydrocarbon surfactants. Finally, a way of removing the mean components of a fire fighting foam from the waste water resulting from fire fighting training or a real application is presented.     

Analytical developments and applications of ionic liquids for environmental studies

Ionic liquids (ILs) are considered advanced solvents with interesting properties that have led to remarkable improvements in the performance of analytical methods and their practical application. Analytical chemistry has profited from the evolution of ILs in diverse contexts, ranging from their applications in microextractions to uses as matrices for mass spectrometric determinations. Their use in sample preparation has meant significant improvements in terms of miniaturization and analytical performance, and given place to new techniques based on liquid-liquid and solid-phase extractions; the latter greatly driven forward by the combination of ILs with nanomaterials. Furthermore, electrodes have been prepared by combining ILs with different modern materials, significantly improving the sensitivity and selectivity of electroanalytical methods. Moreover, the implementation of ILs as additives to mobile and stationary phases in separation techniques has been proved to improve liquid and gas chromatography, as well as capillary electrophoresis, in terms of the number of analytes that can be efficiently separated and of the useful life of columns, representing also a promising alternative to environmentally dangerous organic solvents. Additionally, their application as matrix modifiers and as ion-pairing additives has introduced their use in mass spectrometry. In this review, the design and implementation of innovative and highly efficient analytical methods based on ILs for the sensitive and selective determination of diverse analytes in environmental matrices is described. Critical issues that have arisen from their application and future challenges in electrochemical, separation and preconcentration techniques based on these solvents are also presented.     

Monitoring enzymatic conversions by mass spectrometry: a critical review

This review highlights recent advances in the application of electrospray ionisation and matrix-assisted laser desorption/ionisation mass spectrometry (MS) to study enzymatic reactions. Several assay schemes for different fields of application are presented. The employment of MS as a means of detection in pre-steady-state kinetic studies by rapid-mixing direct analysis and rapid-mixing quench flow techniques is discussed. Several steady-state kinetic studies of a broad range of different enzymatic systems are presented as well as enzyme inhibition studies for various target enzymes. As a promising new development multiplex assays, which monitor the conversion of several substrates simultaneously in one experiment, are described. This assay type has been used for competition studies, enzymatic activity screenings and for diagnostic purposes in clinical chemistry. Generally, it can be concluded that mass spectrometry offers an intriguing alternative as detection methodology in enzymatic bioassays. Its applicability for the monitoring the conversion of naturally occurring substrates and its overall versatility make MS an especially promising tool for the study of enzyme-catalysed processes.     

电热原子吸收分析中的固体进样技术

本文综述了电热原子吸收分析中固体进样技术的进展,详细讨论了固体直接进样和悬浮体进样和样品制备方法、进样工具、校正曲线、基体改进技术、分析性能及其最新应用。     

Organic solvent and temperature-enhanced ion chromatography-high resolution mass spectrometry for the determination of low molecular weight organic and inorganic anions

There has recently been increased interest in coupling ion chromatography (IC) to high resolution mass spectrometry (HRMS) to enable highly sensitive and selective analysis. Herein, the first comprehensive study focusing on the direct coupling of suppressed IC to HRMS without the need for post-suppressor organic solvent modification is presented. Chromatographic selectivity and added HRMS sensitivity offered by organic solvent-modified IC eluents on a modern hyper-crosslinked polymeric anion-exchange resin (IonPac AS18) are shown using isocratic eluents containing 5–50 mM hydroxide with 0–80% methanol or acetonitrile for a range of low molecular weight anions (<165 Da). Comprehensive experiments on IC thermodynamics over a temperature range between 20–45 °C with the eluent containing up to 60% of acetonitrile or methanol revealed markedly different retention behaviour and selectivity for the selected analytes on the same polymer based ion-exchange resin. Optimised sensitivity with HRMS was achieved with as low as 30–40% organic eluent content. Analytical performance characteristics are presented and compared with other IC-MS based works. This study also presents the first application of IC-HRMS to forensic detection of trace low-order anionic explosive residues in latent human fingermarks.     

蛋白质组的分离与分析及其应用进展

蛋白质组学正在成为分析化学研究的热点。本文综述了蛋白质组的高通量分离和分析技术，包括双向凝胶电泳、生物质谱、二维谱新技术和蛋白芯片的发展现状以及蛋白质组学的最新应用进展，并展望了分析化学在蛋白质组学领域今后的发展。