The Importance of Solvent Venting to Reduce Memory Effects with On-Line LC-GC-AED

Reszke²,

Broekaert

et al. 2011

The art and science of microwave plasma (MWP) optical and mass spectroscopy is briefly presented including very recent advances in the field up to 2011. The use of MWPs as radiation sources for optical emission spectroscopy (OES) and atomic fluorescence spectroscopy (AFS) and as atom reservoirs for atomic absorption spectroscopy (AAS), cavity ringdown spectroscopy (CRDS), and laser‐enhanced ionization spectroscopy (LEIS) as well as ion sources for mass spectrometry (MS) is treated. Devices for producing both E‐type capacitively coupled microwave plasma (CMP)‐electrode and microwave‐induced plasma (MIP)‐electrodeless MWPs, including inductively coupled plasma (ICP)‐like H‐type plasmas, are classified and discussed, in addition to methods of their diagnostics, and results for the analytically relevant plasma parameters are presented. The means of generation of symmetrical plasmas and uses of microplasma devices are also presented with an effort to comment on general classification of microwave (MW) cavities. Further, the use of MWs for boosting of glow discharges (GDs) is treated along with other tandem sources. Methods for the introduction of gaseous, liquid, and solid samples into the MWP are discussed. They include direct vapor sampling (DVS), chemical vapor generation (CVG), and hydride generation (HG) techniques; dry aerosol generation techniques (electrothermal vaporization (ETV); spark ablation (SA); laser ablation (LA); and continuous powder introduction (CPI) as well as wet aerosol generation techniques using both solution and slurry nebulization. Special reference is made to coupling with gas chromatography (GC) and also with various separation techniques for liquids including high‐performance liquid chromatography (HPLC). The analytical figures of merit in the case of OES with low‐power and high‐power MIP, CMP, microwave plasma torch (MPT), MWP‐electrode sources including rotating field sustained plasma and H‐type MWP as well as microplasmas are given. There are also described cases of atomic absorption, fluorescence, and laser ionization with these sources. The developments in MS in the case of both low‐power and high‐power MWPs and in the case of various types of sample introduction techniques are discussed. Applications of MWP analytical spectroscopy are in the fields of biological samples with special reference to microanalysis, and of environmental and industrial samples with special emphasis on element speciation, on‐line monitoring, particle sizing, and direct solids analysis. A critical comparison of the methodology with other spectroscopic methods for the determination of the elements and their species is given.

Microwave Plasma Systems in Optical and Mass Spectroscopy

Reszke²,

Broekaert

et al. 2011

Microwave Plasma Systems in Optical and Mass Spectroscopy

Reszke²,

Broekaert

2016

The art and science of microwave plasma (MWP) optical and mass spectroscopy is briefly presented including very recent advances in the field up to 2015. The use of MWPs as radiation sources for optical emission (OES) and atomic fluorescence (AFS) spectroscopy and as atom reservoirs for atomic absorption (AAS) and cavity ringdown (CRDS) spectroscopy as well as ion sources for both elemental and molecular mass spectrometry (MS) is treated. Devices for producing both E‐type capacitively coupled microwave plasma (CMP)‐electrode and microwave‐induced plasma (MIP)‐electrodeless MWPs, including ICP‐like H‐type plasmas, are classified and discussed, in addition to techniques of their diagnostics, and results for the analytically relevant plasma parameters are presented. The means of generation of voluminous symmetrical plasmas and uses of microplasma devices are also presented with an effort to comment on general classification of microwave cavities. Further, the use of microwaves for boosting of glow discharges (GDs) and laser‐induced plasmas (LIBS) is treated along with other tandem sources. Methods for introduction of gaseous, liquid, and solid samples into the MWP are discussed. They include direct vapor sampling (DVS), chemical vapor generation (CVG) and hydride generation (HG) techniques, dry aerosol generation techniques (electrothermal vaporization (ETV), spark (SA) and laser ablation (LA) and continuous powder introduction (CPI)), and wet aerosol generation techniques using both solution and slurry nebulization. Special reference is made to coupling with gas chromatography (GC) and also with various separation techniques for liquids including high‐performance liquid chromatography (HPLC), supercritical fluid chromatography (SFC), and size‐exclusion chromatography (SEC). The analytical figures of merit in the case of OES with MIPs, CMPs, microwave plasma torch (MPT), MWP‐electrode sources including rotating‐field‐sustained plasma, and H‐type MWP as well as microplasmas are given. There are also described cases of atomic absorption and fluorescence with these sources. The developments in both elemental and molecular MS in the case of both cold and hot MWPs and in the case of various types of sample introduction techniques are discussed. Applications of MWP analytical spectroscopy are in the fields of biological, clinical, environmental, and industrial samples with special reference to multielement analysis, element speciation, on‐line monitoring, particle sizing, and direct solids analysis. A critical comparison of the methodology with other spectroscopic methods for the determination of the elements and their species is given.

Microwave Plasma Systems in Optical and Mass Spectrometry

Reszke²

2023

Over the last decade, a revolutionary progress in both the instrumentation and the application of microwave plasma (MWP) systems for optical and mass spectrometry is observed. In this article, the current status of these systems is comprehensively reviewed and updated to 2022 to provide the reader with an advanced understanding of the theory, practices, and instrumentation associated with MWP‐based spectrometric techniques. Diverse MWP devices that can serve as atomizers, and radiation or ionization sources for various spectrometric techniques are all discussed and classified according to their fundamental microwave features and power coupling mode. Two basic MWP types constitute electrode‐operating capacitively coupled microwave plasmas (CMPs) and electrodeless microwave‐induced plasmas (MIPs). The recent development of the brand new devices such as microwave inductively coupled plasmas, rotating field MWPs, and microwave micro‐discharges is also discussed. In addition, so‐called tandem plasma sources that are a combination of MWP with another type of plasma are briefly commented on. An introduction to the various sampling techniques that can cope with MWPs such as hydride generation (HG), chemical vapor generation (CVG) and photochemical vapor generation (PCVG) for gaseous samples, solution nebulization for liquids, and dry aerosol generation techniques [electrothermal vaporization (ETV), spark (SA), laser ablation (LA), direct vaporization and ionization (DI), and continuous powder introduction (CPI)] for solids are presented highlighting their relative merits and demerits. Also, recent advances in sampling of nanoparticles for time‐resolved measurements and single particle analysis are mentioned. Further, a broad range of MWP‐based optical and mass spectrometric techniques is covered. Optical emission spectrometric (OES) methods based on MWPs are reviewed because a considerable amount of research is presently being performed in this field. Even when much less reported in the literature, several nonemission spectrometric techniques are also discussed. The mass spectrometry (MS) techniques including both the elemental mass spectrometry with hot MWPs and a variety of molecular MS techniques utilizing either hot or cold MWPs are discussed. Advances in sample introduction strategies, instrument optimization, calibration methods, and applications of MWP analytical spectrometry are discussed in the following sections. Due to the diversity of MWP instrumentation and related spectrometric techniques, it is impracticable to treat equally all of these issues in this survey. For this reason, the discussion of analytical performance and practical use is focused on key MWP‐based spectrometric techniques that have been employed, alone or hyphenated, using commercial instrumentation. The review of routine determination of metals and metalloids in different categories of samples is focused to cover the application of nitrogen MWP Optical Emission Spectrometer. Extended capabilities by hyphenating microwave plasma optical emission spectrometry (MWPOES) and microwave plasma mass spectrometry (MWPMS) to various well‐known separation techniques such as gas or liquid chromatography, and also size‐exclusion chromatography are discussed in brief. The application of advanced spectroscopic techniques in a wide range of environments focusing mainly, but not exclusively, on industrial and bioanalytical applications, its advantages, and limitations over other multielement instrumental techniques are discussed. Some of the areas where more developments can be expected in the future are suggested.