Recent trends and developments in laser ablation-ICP-mass spectrometry

The increased interest in laser technology (e.g. for micro-machining, for medical applications, light shows, CD-players) is a tremendous driving force for the development of new laser types and optical set-ups. This directly influences their use in analytical chemistry. For direct analysis of the elemental composition of solids, mostly solid state lasers, such as Nd:YAG laser systems operating at 1064 nm (fundamental wavelength), 266 nm (frequency quadrupled) and even 213 nm (frequency quintupled) have been investigated in combination with all available inductively coupled plasma mass spectrometers. The trend towards shorter wavelengths (1064 nm– 157 nm) was initiated by access to high quality optical materials which led to the incorporation of UV gas lasers, such as excimer lasers (XeCl 308 nm, KrF 248 nm, ArF 193 nm, and F₂ 157 nm) into laser ablation set-ups. The flexibility in laser wavelengths, output energy, repetition rate, and spatial resolution allows qualitative and quantitative local and bulk elemental analysis as well as the determination of isotope ratios. However, the ablation process and the ablation behavior of various solid samples are different and no laser wavelength was found suitable for all types of solid samples. This article highlights some of the successfully applied systems in LA-ICP-MS. The current fields of applications are explained on selected examples using 266 nm and 193 nm laser ablation systems.     

Recent trends and developments in pyrolysis-gas chromatography

Pyrolysis-gas chromatography (Py-GC) has become well established as a simple, quick and reliable analytical technique for a range of applications including the analysis of polymeric materials. Recent developments in Py-GC technology and instrumentation include laser pyrolysis and non-discriminating pyrolysis. Progress has also been made in the detection of low-level polymer additives with the use of novel Py-GC devices. Furthermore, it has been predicted that future advances in separation technology such as the use of comprehensive two-dimensional gas chromatography will further enhance the analytical scope of Py-GC.     

Recent developments in quantitative mass spectrometry

New procedures in quantitative mass spectrometry (MS) continue to follow very closely the development of qualitative methods. The burgeoning of MS techniques appropriate to the analysis of polar and non-volatile compounds has produced a corresponding increase in the scope of quantitative MS. In general, quantitative procedures based on the newer methods (such as fast-atom bombardment, liquid chromatography-MS, MS-MS) have not yet reached the point of quantitative refinement that may be expected of gas chromatography. Nevertheless, with increased understanding of the newer methods, significant improvements in quantification may be confidently anticipated.     

毛细管电泳-质谱联用技术的新进展

毛细管电泳-质谱(CE-MS)联用技术综合了CE的高效分离能力、广泛的样品适应性和MS的高灵敏度、可提供结构信息等优势,已发展成为一种重要的分离分析手段。本文对近几年来CE-MS联用接口技术的发展作一简单介绍,并对CE-MS在生命分析、食品药品分析等领域的一些应用进展予以综述。     

Development of an on-line low gas pressure cell for laser ablation-ICP-mass spectrometry.

An on-line low gas pressure cell device has been developed for elemental analysis using laser ablation-ICP-mass spectrometry (LA-ICPMS). Ambient gas in the sample cell was evacuated by a constant-flow diaphragm pump, and the pressure of the sample cell was controlled by changing the flow rate of He-inlet gas. The degree of sample re-deposition around the ablation pit could be reduced when the pressure of the ambient gas was lower than 50 kPa. Produced sample aerosol was drawn and taken from the outlet of the diaphragm pump, and directly introduced into the ICP ion source. The flow rate of He gas controls not only the gas pressure in the sample cell, but also the transport efficiency of the sample particles from the cell to the ICP, and the gas flow rate must be optimized to maximize the signal intensity of the analytes. The flow rates of the He carrier and Ar makeup gas were tuned to maximize the signal intensity of the analytes, and in the case of (238)U from the NIST SRM610 glass material, the signal intensity could be maximized with gas flow rates of 0.4 L/min for He and 1.2 L/min for Ar. The resulting gas pressure in the cell was 30 - 35 kPa. Using the low gas pressure cell device, the stability in the signal intensities and the resulting precision in isotopic ratio measurements were evaluated. The signal intensity profile of (63)Cu obtained by laser ablation from a metallic sample (NIST SRM976) demonstrated that typical spikes in the transient signal, which can become a large source of analytical error, were no longer found. The resulting precision in the (65)Cu/(63)Cu ratio measurements was 2 - 3% (n = 10, 2SD), which was half of the level obtained by laser ablation under atmospheric pressure (6 - 10%). The newly developed low-pressure cell device provides easier optimization of the operational conditions, together with smaller degrees of sample re-deposition and better stability in the signal intensity, even from a metallic sample.     

Recent developments and future trends in injection molding technology

The amount of plastic components of passenger cars in Japan has increased extremely past 25 years. Many of them are produced by injection molding. There are a number of significant developments in injection molding technology. These developments involve CAE (Computer Aided Engineering) including the prediction of the properties of molded parts, innovative experiments to analyze processing, new machineries (processing) and recycling plastics.     

Low-pressure gas chromatography: Recent trends and developments

In the past few years, low-pressure gas chromatography (LP-GC) has been applied for the fast analysis of various pollutants in different environmental and food matrices. A typical LP-GC set-up involves the use of a short microbore column (typically 0.5–1 m × 0.10 mm internal diameter) at the injector side connected with a zero dead-volume connector to a short megabore column (typically 10 m × 0.53 mm) to be used with higher gas velocities. This set-up maintains atmospheric injection conditions, while the analytical column is operated under low-pressure conditions that are compatible with mass-spectrometer analyzers. Although the use of LP-GC results in a loss of separation efficiency, it offers a 3–5-fold reduction in analysis time for organic compounds and thus increased sample throughput and enhancement of the signal-to-noise ratio leading to improved detection limits. Considering the significance of, and the potential interest in, this topic, this review briefly describes the concept of LP-GC. Furthermore, we explore recent developments and applications of LP-GC, with a focus on the use of various column systems and analyzers. Finally, we critically evaluate the prospects for, and the limitations of, LP-GC.     

Recent trends and developments in dissolving pulp production and application

This work provides a critical overview of the recent trends toward the development of modern, dissolving pulp production technologies that respond to the current challenges and opportunities for the emerging low-carbon bioresource economy. Special attention is paid to recent advancements in prehydrolysis kraft pulping and conversion of paper grade pulp to dissolving pulp, with emphasis on the valorization of hemicellulose to value-added products. A comprehensive analysis of the current and future developmental opportunities for novel bioprocessing technologies and new products from dissolving pulp that aim to improve the process economics and enhance the industry competitiveness is presented and discussed.     

Recent developments in analytical ion trap mass spectrometry

The current status of quadrupole ion trap mass spectrometry is reviewed, with particular emphasis on liquid chromatographic coupling, membrane inlet introduction, laser desorption/ionisation and selective chemical ionisation. The flexibility, high sensitivity and multi-stage tandem mass spectrometric capability of the quadrupole ion trap are all illustrated.     

Recent developments in and applications of resonance ionization mass spectrometry

Resonance Ionization Mass Spectrometry (RIMS) has nowadays reached the status of a routine method for sensitive and selective ultratrace determination of long-lived radioactive isotopes in environmental, biomedical and technical samples. It provides high isobaric suppression, high to ultra-high isotopic selectivity and good overall efficiency. Experimental detection limits are as low as 10⁶ atoms per sample and permit the fast and sensitive determination of ultratrace amounts of radiotoxic contaminations. Experimental arrangements for the detection of different radiotoxic isotopes, e.g. ^236–244Pu, ^89,90Sr and ⁹⁹Tc in environmental samples are described, and the application of RIMS to the ultrarare long-lived radioisotope ⁴¹Ca for cosmochemical, radiodating and medical purposes are presented. Received: 17 December 1998 / Revised: 11 February 1999/Accepted: 18 February 1999     

Recent developments in and applications of resonance ionization mass spectrometry

Resonance Ionization Mass Spectrometry (RIMS) has nowadays reached the status of a routine method for sensitive and selective ultratrace determination of long-lived radioactive isotopes in environmental, biomedical and technical samples. It provides high isobaric suppression, high to ultra-high isotopic selectivity and good overall efficiency. Experimental detection limits are as low as 10⁶ atoms per sample and permit the fast and sensitive determination of ultratrace amounts of radiotoxic contaminations. Experimental arrangements for the detection of different radiotoxic isotopes, e.g. ^236–244Pu, ^89,90Sr and ⁹⁹Tc in environmental samples are described, and the application of RIMS to the ultrarare long-lived radioisotope ⁴¹Ca for cosmochemical, radiodating and medical purposes are presented. Received: 17 December 1998 / Revised: 11 February 1999/Accepted: 18 February 1999     

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.     

Recent developments in atomizers for electrothermal atomic absorption spectrometry

This review first describes general requirements to be met for suitable base materials used to produce electrothermal atomizers (ETAs). In this connection the physical and chemical properties of adequate types of graphite and metals are discussed. Further, various atomizer designs, their temperature dynamics during atomization and general performance characteristics are critically reviewed. For end-heated Massmann-type atomizers, discussions are focused on recent developments of, e.g., contoured tubes to achieve improved temperature homogeneity over the tube length, second surface atomizers to realize temporally isothermal atomization and tubes with graphite filters to reduce interference effects. The state-of-the-art of platform equipped, side-heated atomizers with integrated contacting bridges are characterized mainly with respect to heating dynamics, as well as susceptibility to interference- and memory effects. In contrast to end-heated ETAs, the tube ends of side-heated ETAs are freely located in the furnace compartment and, as a consequence of this configuration, convective gas flows can easily appear. The magnitude and effect of these flows on analytical performance are discussed and measures are suggested, permitting operation under diffusion controlled conditions. A critical comparison of classical constant temperature atomizers with state-of-the-art platform equipped ETAs is made and from this it is concluded that future ETA developments are likely to involve only minor modifications aiming at, e.g., the reduction of cycling times or the improvement of tube surface properties.     

Recent developments in the analytical application of prompt spectrometry

A survey of the possibilities of analysis by alpha-induced prompt gamma-ray spectrometry is reported for 57 elements at a bombarding energy of 5 MeV. Additional data obtained at 11 and 16 MeV are given. Interference-free sensitivities are presented. The use of the position sensitive detector is introduced to overcome problems such as occur in prompt alpha spectrometry from (p, α) reactions. The technique is illustrated by studies on the reaction¹⁹F(p, α)¹⁶O and severely tested for boron analysis using the reaction¹¹B(p, α)⁸Be and measuring the α₀ and α₁ groups.     

Recent developments in atomizers for electrothermal atomic absorption spectrometry

This review first describes general requirements to be met for suitable base materials used to produce electrothermal atomizers (ETAs). In this connection the physical and chemical properties of adequate types of graphite and metals are discussed. Further, various atomizer designs, their temperature dynamics during atomization and general performance characteristics are critically reviewed. For end-heated Massmann-type atomizers, discussions are focused on recent developments of, e.g., contoured tubes to achieve improved temperature homogeneity over the tube length, second surface atomizers to realize temporally isothermal atomization and tubes with graphite filters to reduce interference effects. The state-of-the-art of platform equipped, side-heated atomizers with integrated contacting bridges are characterized mainly with respect to heating dynamics, as well as susceptibility to interference- and memory effects. In contrast to end-heated ETAs, the tube ends of side-heated ETAs are freely located in the furnace compartment and, as a consequence of this configuration, convective gas flows can easily appear. The magnitude and effect of these flows on analytical performance are discussed and measures are suggested, permitting operation under diffusion controlled conditions. A critical comparison of classical constant temperature atomizers with state-of-the-art platform equipped ETAs is made and from this it is concluded that future ETA developments are likely to involve only minor modifications aiming at, e.g., the reduction of cycling times or the improvement of tube surface properties.     

Recent developments in capillary electrophoresis-mass spectrometry of proteins and peptides.

Many researchers have invested considerable efforts toward improving capillary electrophoresis (CE)-mass spectrometry (MS) systems so they can be applied better to standard analyses. This review highlights the developments in CE-MS of proteins and peptides over the last five years. It includes the developments in interfaces, sample-enrichment techniques, microfabricated devices, and some applications, largely in capillary zone electrophoresis (CZE), capillary isoelectric focusing (CIEF) and capillary isotachophoresis formats.     

Flow injection-electrothermal atomic absorption spectrometry configurations: recent developments and trends

This review aims to provide an account of the state-of-the-art, of recently introduced techniques and of future possibilities offered by flow analysis in order to automate sample pretreatment for electrothermal atomic absorption spectrometry (ETAAS). Topics such as on-line solid-liquid extraction, precipitation, coprecipitation, on-wall retention, solvent extraction and chemical vapor generation processes are used to illustrate the versatility of coupling flow injection (FI) for analyte separation and preconcentration in the flow system or in the atomizer. The use of FI to make the introduction of slurries and highly viscous samples easier is considered as well as on-line microwave sample digestion.     

On-line electrothermal atomic absorption spectrometry configurations: recent developments and trends

In the present mini-review, an account of the actual state-of-the-art and future possibilities offered by on-line ET-AAS is presented. Topics such as: (1) on-line analyte preconcentration (by means of precipitation, sorption, solvent extraction, and solid phase extraction); (2) analyte separation by means of chromatography, and electrochemical, microdialysis and chemical vapor generation processes; and (3) sample treatment (by microwave sample digestion, sample emulsification and dilution processes) are used to illustrate the versatility of flow injection, sequential injection analysis, stop flow and continuous flow, when coupled to a graphite furnace. The use of some of the on-line systems for speciation and the simultaneous determination of different analytes is underlined.     

Recent developments in atomic spectrometry methods for elemental trace determinations

Summary Methods for atomic spectrometry are discussed in view of progress for elemental trace analysis and with special reference to progress in power of detection and in analytical reliability as well as with respect to economic aspects. Optical methods basing on atomic emission, absorption and fluorescence principles as well as related techniques (optogalvanic spectroscopy and coherent forward scattering), X-ray spectrometry and mass spectrometry are treated. The state-of-the-art, trends of development and new techniques such as special sample introduction for plasma spectrometry, glow discharges, laser enhanced ionization spectrometry with a thermionic diode, X-ray spectrometry with total reflection, plasma and glow discharge mass spectrometry are drawn up. Their potential interest from the point of power of detection, multielement capacity, interferences, capabilities for micro- and local analysis and speciation is compared with that of other methods for elemental analysis.

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Neue Entwicklungen atomspektrometrischer Methoden für die Elementspurenanalyse

Zusammenfassung Für die atomspektrometrischen Methoden wird der Fortschritt im Hinblick auf Nachweisvermögen, analytische Zuverlässigkeit und Kosten diskutiert. Optische Methoden wie die Emissions-, Atomabsorptionsund Fluorescenzspektrometrie, aber auch verwandte Techniken (Optogalvanik und kohärente Vorwärtsstreuung), neue röntgenspektrometrische Methoden und massenspektrometrische Verfahren werden behandelt. Es werden der Stand der Technik, die Entwicklungstendenzen und neue Techniken wie spezielle Probenzuführungsmethoden für die Plasmaspektrometrie, Glimmentladungen, die laserinduzierte Ionisationsspektrometrie, die Röntgenfluorescenzspektrometrie mit Totalreflektion und der Einsatz des induktiv gekoppelten Plasmas und von Glimmentladungen als Ionenquellen für die Massenspektrometrie dargestellt. Das Nachweisvermögen, die Multielementkapazität, die Interferenzen, die Möglichkeiten für Mikro- und Verteilungsanalysen sowie für die Bestimmung der Bindungsform bei den Methoden der Atomspektrometrie werden mit denen anderer Methoden für die Bestimmung der chemischen Elemente verglichen.

     

Recent developments in ambient ionization techniques for analytical mass spectrometry

Ambient ionization techniques enable the interrogation of a variety of samples in their native state by mass spectrometry, and are rapidly advancing all fields where screening for the presence of various analytes in a broadband and/or high-throughput fashion is desirable. This Highlight article provides an introduction to the field, and showcases the different ionization approaches reported since 2004, with an emphasis on the most recent developments.