Slurry Nebulization in Plasmas for Analysis of Inorganic Materials

Abstract

This review summarizes and discusses the preparation of slurries for analysis of inorganic materials by inductively coupled plasma optical emission spectrometry (ICP‐OES) and inductively coupled plasma mass spectrometry (ICP‐MS). Details about the grinding step for slurry preparation, the stabilization of slurries, and the calibration strategies are critically discussed. Typical applications described in the literature and the state‐of‐the‐art including advantages and limitations of slurry analysis are presented.     

Application of Multivariate Techniques in Optimization of Spectroanalytical Methods

Abstract

The present article describes fundamentals and applications of multivariate techniques used for the optimization of analytical procedures and systems involving spectroanalytical methods such as flame atomic absorption spectrometry (FAAS), electrothermal atomic absorption spectrometry (ETAAS), inductively coupled plasma optical emission spectrometry (ICP OES), and inductively coupled plasma mass spectrometry (ICP‐MS), considering the main steps of a chemical analysis. This way, applications of experimental designs in optimization of sampling systems, digestion procedures, preconcentration procedures, instrumental parameters of quantification steps of analytical methods, and robustness tests have been summarized in this work.     

用于实时溅射深度测量的新型Grimm辉光放电光源的设计

采用辉光放电光谱仪进行物质表面深度分析时,样品溅射深度是重要的分析信息.本文设计了一种新型Grimm辉光放电光源,此光源与激光位移测距传感器构成的测昔系统可对样品溅射深度进行实时测量,并保证了良好的辉光溅射效果和分辨多层结构及界面的能力.采用激光三角测量技术,在辉光光谱分析的同时对溅射深度进行实时测量,能够有效地解决传统深度分析方法中步骤繁琐以及对深度估算不准确等问题.本光源采用光纤将辉光光谱信号从光源传至多道分光光电检测系统,在结构上首次实现了元素光谱信号和溅射深度信号的实时采集及基于时间的同步分析,对标准样品得到了理想的实时溅射深度测量曲线.本文详细介绍了此新型辉光放电光源的设计思路和工作原理.本辉光放电光源具有良好的深度分辨率,在30 mA,900 V,20 min的溅射条件下,对铁基和铜基样品的溅射速率分别约为10和55 nm·s-1,文中给出了样品的溅射坑表面形貌图和溅射坑显微照片.对中低合金钢标准样品进行了分析精密度实验,分析精度良好,其中C,Cu,Al,Ni,Mo,Mn,V元素相对标准偏差(RSD)均小于1.7%.Cr和Si元素RSD小于2.6%,给出了实测数据.     

强短脉冲供电辉光放电发射光谱法测定铜基合金组分的研究

文中所述的研究用实验室组装的强短脉冲供电辉光放电发射光谱（ＨＣＭＳＰＧＤ－ＯＥＳ）实验系统，对铜基合金中的次要组分Ｎｉ，Ａｌ，Ｍｎ，Ｓｉ的含量进行了测定，辉光放电（ＧＤ）源在强短脉冲供电（ＨＣＭＳＰ）时，原子线和离子线的发射得到增强，文中选用了Ｎｉ，Ａｌ，Ｍｎ，Ｓｉ的次灵敏线作分析线，对影响分析强度的因素进行了研究，在选定的实验条件下几种组分的含量进行了测定，测定结果与样品的推荐值吻合较好，六次侧     

Microplasma Technology and Its Applications in Analytical Chemistry

Abstract

This review article describes some existing microplasma sources and their applications in analytical chemistry. These microplasmas mainly include direct current glow discharge (DC), microhollow-cathode discharge (MHCD) or microstructure electrode (MSE), dielectric barrier discharge (DBD), capacitively coupled microplasmas (CCμPs), miniature inductively coupled plasmas (mICPs), and microwave-induced plasmas (MIPs). The historical development and recent advances in these microplasma techniques are presented. Fundamental properties of the microplasmas, the unique features of the reduced size and volume, as well as the advantageous device structures for chemical analysis are discussed in detail, with the emphasis toward detection of gaseous samples. The analytical figures of merit obtained using these microplasmas as molecular/elemental-selective detectors for emission spectrometry and as ionization sources for mass spectrometry are also given in this review article.     

Laser Ablation Inductively Coupled Plasma Mass Spectrometry: Principles and Applications

Abstract

The application of laser ablation inductively plasma mass spectrometry (LA‐ICP‐MS) to the determination of major, minor, and trace elements as well as isotope‐ratio measurements offers superior technology for direct solid sampling in analytical chemistry. The advantages of LA‐ICP‐MS include direct analysis of solids; no chemical dissolution is necessary, reduced risk of contamination, analysis of small sample mass, and determination of spatial distributions of elemental compositions. This review aims to summarize recent research to apply LA‐ICP‐MS, primarily in the field of environmental chemistry. Experimental systems, fractionation, calibration procedures, figures of merit, and new applications are discussed. Selected applications highlighting LA‐ICP‐MS are presented.     

Annealed Ni/Ti/SiC structure analysed by SIMS and GDMS

Depth profile analysis was performed using two mass spectrometry analytical techniques applying argon ion sputtering—secondary ion mass spectrometry (SIMS) and glow discharge mass spectrometry (GDMS). 150 nm Ni/20 nm Ti/4H-SiC structure was prepared by evaporation coating with titanium and nickel. The structure was analysed as prepared and annealed in 600°C in dry N₂. Obtained results allow monitoring several processes present during annealing of Ni/Ti/SiC structures. These are nickel diffusion and its reaction with SiC leading to formation of Ni₂Si, precipitation of carbon and segregation of titanium. Results are also used for comparison of the two analytical techniques used. The techniques base on different ionisation mechanisms. In SIMS, secondary ions are formed at the bombarded surface during ion sputtering process in ultra-high vacuum environment, while in GDMS, ionisation occurs in glow discharge above the eroded surface in low vacuum.     

Molybdenum,Platinum, and Tantalum Metal Atomizers or Vaporizers in Analytical Atomic Spectrometry

Abstract

The application of metal (tantalum, molybdenum, and platinum) devices in analytical atomic spectrometry is reviewed in this article. These metal devices have been employed in various analytical atomic spectrometric techniques for more than three decades, mainly as electrothermal atomizers or electrothermal vaporizers, in various physical shapes, such as tubes, platforms, loops, and wires (or coils/filaments). Their application spans from atomic absorption spectrometry (AAS), atomic emission spectrometry (AES) atomic fluorescence spectrometry (AFS), inductively coupled plasma atomic emission spectrometry (ICP‐AES) to inductively coupled plasma mass spectrometry (ICP‐MS). The analytical figures of merit and the practical applications reported for these metal devices are reviewed, and the atomization mechanism on these metal atomizers is briefly summarized, too. In addition, other applications of the metal devices are discussed, including analyte preconcentration by electrodeposition and sequential metal vapor elution analysis (SMVEA). Furthermore, the application of these metals in graphite furnaces encompasses the schemes with the metals in the form of furnace linings, platforms, or impregnated salts.     

Electrolyte Cathode Atmospheric Glow Discharges for Direct Solution Analysis

Abstract

The electrolyte cathode atmospheric glow discharge (ELCAD) invented in 1992 is a new optical emission source with upcoming application in the field of environmental protection as an outstanding instrument for monitoring the toxic heavy metal content of waters and wastewaters. The main operating parameters, mechanisms (secondary electron emission from the electrolyte cathode, self‐sustaining processes in the cathode dark space, dependence of the emitted line intensities on the discharge parameters, temperatures), and the analytical performance of this special discharge are presented through a critical review using the papers related to the ELCAD published from 1993 to 2006.     

Mass Spectrometric Determination of Transuranium Elements

Abstract

Mass spectrometric techniques are playing a predominant role for the determination of transuranium elements in bulk samples as well as in microparticles. Their applications to liquid and solid samples for the determination of the isotopic composition as well as for the concentration measurements are discussed. The new developments for the characterization of microparticles stemming from different release scenarios of radioactivity are considered. Inductively coupled plasma mass spectrometry and its hyphenation with other techniques for resolving isobaric interferences are presented. The application of glow discharge and laser ablation directly to solid samples is highlighted. Finally, the exploitation of secondary ion mass spectrometry, accelerator mass spectrometry, resonance ionization mass spectrometry, and thermal ionization mass spectrometry for the determination of the isotopic composition of uranium and plutonium in microparticles is illustrated.     

激光诱导击穿光谱在材料表面分析领域中的应用进展

激光诱导击穿光谱作为表面分析工具是近十年发展起来的,对表面分析基础理论、仪器装置及其在材料科学领域中的应用进行详细的综述。重点阐述了激光诱导击穿光谱在国内外冶金、半导体、电子等材料科学领域中的元素分布分析及镀层分析应用进展,指出激光束单个脉冲能量、环境气体及气压、激光束能量分布等参数对分辨率的影响,同时指出在兼顾灵敏度的前提下提高分辨率的途径。与传统经典表面分析工具相比较具有扫描面积大、分析速度快及样品导电与否均可分析等优点,成为传统表面分析工具的有力补充。     

Lasers as Light Sources for Analytical Atomic Spectrometry

Abstract

Lasers have advantages compared to conventional light sources, which include high power, a monochromatic emission profile, stability, and rapid tuning across an atomic line. These advantages have resulted in superior analytical figures of merit and methods of background correction compared to conventional light sources. The most widely used lasers for atomic spectrometry include dye laser systems, optical parametric oscillator systems, and diode lasers. Three principal techniques employ lasers as light sources. Laser‐excited atomic fluorescence spectrometry (LEAFS) involves the use of laser light to excite atoms that emit fluorescence and serves as the analytical signal. Laser‐enhanced ionization (LEI) involves laser excitation of atoms to an excited state energy level at which collisional ionization occurs at a higher rate than from the ground state. Diode laser atomic absorption spectrometry (DLAAS) employs a DL as a source to excite atoms in an atom cell from the ground state to an excited state. The analytical signal is involves the ratio of the incident and transmitted beams. Recent applications of these techniques are discussed, including practical applications, hyphenated techniques employing laser‐induced plasmas, and work to characterize fundamental spectroscopic parameters.     

格里姆辉光放电光源的发展和应用范围

本文评述了辉光放电光源的一些进展情况。对高强度辉光放电灯，磁场辉光放电灯，射频、微波辉光放电灯，同轴双重空心阳极辉光放电灯等技术在增加辉光放电光源的发光强度、降低检出限、提高逐层分析中的层间分辨率等方面的作用作了介绍。也同时介绍了这种光源在金属与合金固体样品直接分析及这些材料的表层、逐层分析中的应用范围。     

Gas Chromatography Analysis of Discharge Products in N2‐CH4 Gas Mixture at Atmospheric Pressure: Study of Mimic Titan's Atmosphere

In this paper, we report presence of various organic products formed in a flowing atmospheric glow discharge fed by gas mixture containing 1‐5 % of methane in nitrogen, which mimics the Titan's atmosphere. Gaseous products from the discharge exhaust were analysed by Gas Chromatography with Mass Spectrometry (GC‐MS). The experimental results revealed C₂H₂, HCN, and CH₃CN as the major products. Various hydrocarbons and nitriles were the other determined gaseous products. Whilst many of these compounds have been predicted and/or observed in the Titan atmosphere, the present plasma experiments provide evidence of both the chemical complexity of Titan atmospheric processes and the mechanisms by which larger species grow prior to form the dust that should cover much of the Titan's surface. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Currents on Ultrasound‐Assisted Extraction for Sample Preparation and Spectroscopic Analytes Determination

Abstract

This review reports recent applications of the ultrasonic energy for extracting inorganic and organic analytes from diverse solid samples devoted to spectroscopic analyses. The main advantages resulting from ultrasound comprise the reduction of the procedural time and reagent consumption. In this sense, ultrasound‐assisted extractions can be considered as an efficient tool for improving the analytical performance of procedures employed in analytical chemistry and natural products chemistry. However, a rigorous experimental control is strongly recommended in order to avoid losses in precision and accuracy. Uncontrolled ultrasound‐assisted extraction procedure is also discussed, since ultrasonic irradiation can provoke decompositions of molecules, hindering organic compounds extraction.     

ELECTROLYTE-AS-CATHODE GLOW DISCHARGE (ELCAD)/GLOW DISCHARGE ELECTROLYSIS AT THE GAS-SOLUTION INTERFACE

ABSTRACT

Electrolysis glow discharge (ELCAD), wherein an electrolyte serves as the cathode, is a potential new analytical source for on-line determination of trace heavy metals in waste and drinking waters, in addition to other liquid samples. The use of atomic emission spectrometry (AES) with ELCAD enhances the efficiency of the technique. Although possible applications of ELCAD-AES are widespread, the technique is currently unsuitable for the detection of toxic elements, such as mercury, at concentrations as low as the World Health Organization guideline level in drinking water (1 ng/mL). The aim of this contribution is to provide an overview of the brief history, development of instrumentation, fundamental mechanistic studies and applications of ELCAD. This review suggests that, whereas the scope of ELCAD-AES is diverse, it would benefit greatly from the involvement of more researchers to enhance the capabilities of the system, as otherwise this goal will not be achieved.     

The Hollow Cathode Discharge as a Spectrochemical Emission Source

Abstract

The hollow cathode discharge (HCD), a specialized type of glow discharge, has been the subject of investigations by physicists (in particular) and chemists for over a half century. Several hundred literature reports may be found concerning various aspects of the HCD. Despite this, many analytical chemists today would consider the HCD as merely a sharp line source for atomic absorption spectrometry (AAS). While this is certainly its most important present application, the HCD has a long history as a spectrochemical emission source allowing direct excitation and analysis of samples. Excellent sensitivities have been reported, but experimental difficulties, including construction of a demountable hollow cathode tube, have limited overall past acceptance of the HCD as an analytical emission technique. However, the current interest by analytical spectroscopists in new methods of atomization and excitation has revived interest in glow discharges. Also, the commercial availability of two demountable hollow cathode tubes and associated vacuum systems now allows easy accessibility to the technique.     

Procedures of Separation and Pre‐concentration for Molybdenum Determination Using Atomic Spectrometry—a Review

Abstract

The literature concerning the improvement of atomic and ionic procedures for molybdenum determination through separation and pre‐concentration were updated. Analytical procedures based on flame atomic absorption spectrometry (AAAS), electrothermal or graphite furnace atomic absorption spectrometry (GFAAS), inductively coupled plasma optical emission spectrometry (ICP‐OES), and inductively coupled plasma mass spectrometry were reviewed taking into consideration the preliminary steps, which can enhance the selectivity and sensitivity based on co‐precipitation, solvent extraction, and solid‐phase extraction. Both in‐batch and on‐line procedures were considered.     

Dielectric Barrier Discharge in Analytical Spectrometry

Abstract

Dielectric barrier discharge is a nonequilibrium plasma, and its industrial application has been on a large scale. Similarly, its prominent features of high dissociation ability at low working temperature and low power consumption, simple and adjustable configuration, ambient working conditions, and long lifetime are favorable for developing a wide array of analytical devices as well. This review addresses the basics of dielectric barrier discharge and emphasizes their analytical applications in analytical atomic spectrometry, chemiluminescence, gas chromatographic detectors, ion source for mass spectrometry, and ion mobility spectrometry with 103 references.