Analytical Atomic Spectrometry Research Articles

Alternative Solid Sample Pretreatment Methods in Green Analytical Atomic Spectrometry

ABSTRACT A review of recent literature utilizing alternative sample pretreatment methods for solid environmental and biological materials analysis to assess total metals content by atomic spectrometry is provided. All the selected treatments coincide with all or some of the fundamentals of Green Chemistry policy such as prevention of waste generation; safer and less toxic solvents and reagents; and designs for energy efficiency. The review covers the classic slurry sampling technique, mainly, its current trends, as well as developments based on the use of diluted acids, chelating agents solutions, or even water for leaching (extraction) methods assisted by ultrasounds, microwave energy, or pressurization. In addition, the use of conventional or assisted enzymatic hydrolysis procedures is also discussed.

Flame Furnace Atomic Absorption Spectrometry: A Review

Flame atomic absorption spectrometry (FAAS) is one of the most widespread traditional analytical techniques for trace element determination, but it often suffers from poor sensitivity due to the low nebulization efficiency and the short residence time of free atoms in the flame. On the basis of conventional FAAS, flame furnace atomic absorption spectrometry (FF-AAS) is developed with a tube (flame furnace) placed on top of the FAAS burner for the atomization. Sample is introduced via beam injection (BIFF-AAS) or thermospray (TS-FF-AAS). Due to the total sample introduction and prolonged residence time of free atoms in the flame furnace, marked sensitivity improvement is obtained for volatile and semivolatile elements over conventional FAAS. TS-FF-AAS can be employed as an element-selective detector for GC, HPLC, or CE for studying of metal speciation analysis and metallomics. In addition, three newly developed sample introduction methods, including ultrasonic nebulization, hydride generation, and pneumatic nebulization, are discussed. The analytical figures of merit and practical applications of FF-AAS in analytical atomic spectrometry are reviewed in this article.

Interference of gadolinium-based contrast agents with the measurement of serum creatinine by the Jaffe reaction

Interference of gadolinium-based contrast agents with the measurement of serum creatinine by the Jaffe reaction

A Novel Chip-based Electroelution System for Rapid and Efficient Recovery of Intact Proteins from Polyacylamide Gels

A Novel Chip-based Electroelution System for Rapid and Efficient Recovery of Intact Proteins from Polyacylamide Gels

A Thermo-Chemical Reactor for analytical atomic spectrometry

A novel atomization/vaporization system for analytical atomic spectrometry is developed. It consists of two electrically and thermally separated parts that can be heated separately. Unlike conventional electrothermal atomizers in which atomization occurs immediately above the vaporization site and at the same instant of time, the proposed system allows analyte atomization via an intermediate stage of fractional condensation as a two stage process: Vaporization → Condensation → Atomization. The condensation step is selective since vaporized matrix constituents are mainly non-condensable gases and leave the system by diffusion while analyte species are trapped on the cold surface of a condenser. This kind of sample distillation keeps all the advantages of traditional electrothermal atomization and allows significant reduction of matrix interferences. Integration into one design a vaporizer, condenser and atomizer gives much more flexibility for in situ sample treatment and thus the system is called a Thermo-Chemical Reactor (TCR). Details of the design, temperature measurements, vaporization–condensation–atomization mechanisms of various elements in variety of matrices are investigated in the TCR with spectral, temporal and spatial resolution. The ability of the TCR to significantly reduce interferences and to conduct sample pyrolysis at much higher temperatures as compared to conventional electrothermal atomizers is demonstrated. The analytical potential of the system is shown when atomic absorption determination of Cd and Pb in citrus leaves and milk powder without the use of any chemical modification.

Visualizing the Solute Vaporization Interference in Flame Atomic Absorption Spectroscopy

Every day, tens of thousands of chemists use analytical atomic spectroscopy in their work, often without knowledge of possible interferences. We present a unique approach to study these interferences by using modern response surface methods to visualize an interference in which aluminum depresses the calcium atomic absorption signal. Calcium atomic absorption measurements are performed on solutions that contain calcium only, calcium plus aluminum, and calcium plus aluminum with lanthanum added as a releasing agent. The interferences are known to be affected by flame temperature, so measurements were made under conditions of varied flame stoichiometry and observation height. Results are displayed using response surfaces generated by regression analysis of the results of a factorial design in which burner height and fuel ratios are varied. Response surface methods allow students to recognize the tradeoffs required to optimize instrumental parameters. The user can chose to optimize operating conditions based on minimizing the solute vaporization interference, maximizing the absorbance, optimizing signal-to-noise ratio, or any combination of these three diagnostic parameters. The conditions needed for stable, reproducible chemical analyses were substantially different from those that produce the maximum signal.

Lasers as Light Sources for Analytical Atomic Spectrometry

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.

What do metals tell us about wine?

This article focuses on analysis of metals in wine in the literature devoted to analytical atomic spectrometry in the past decade. It emphasizes the role of metals in wine and processes involved in winemaking. It covers endogenous and exogenous sources of metals in wine, changes in metal composition during vinification, methods of wine analysis, techniques of wine classification corresponding to distinctive metal patterns, and, finally, approaches to operationally-defined fractionation analysis of metals carried out to understand their nutritional value and bioavailability in wine.

New plasma discharges for atomic spectrometry

Scientific innovation in analytical atomic spectrometry, one of the oldest instrumental methods of chemical analysis, has always depended on the development of new sources, the improvement of existing ones, or the development of novel spectrometers optimized for the sources of interest. This holds true for sample introduction (and atomisation), signal generation (excitation, ionisation, fluorescence, scattering), signal dispersion and detection, regardless of whether we are considering optical or mass spectrometry. The modern atomic spectroscopy era began in the early 1950s due to the development of (electric) flames, arcs and sparks, and it was the focus of many investigations, where furnaces were used as atom reservoirs for atomic absorption studies. Glow discharges were applied as powerful atomic emission spectrometry sources in direct solid and layer analyses performed in the early 1970s. More recently, high-frequencyand microwave-induced plasmas were used for elemental trace analysis, and these were found to be particularly useful in speciation studies where it was coupled on-line with different kinds of chromatography. Further impetus to this field of study was provided by coupling plasma discharges to elemental mass spectrometry [1]. New sources of innovation are also arising from the growing need to obtain better detection limits, especially when it comes to elemental determinations in the smallest compartments, as required in the biomedical and nanosciences, as well as from the demands for miniaturization, such as the drive to produce smaller devices for field-monitoring or process analysis, or simply a new requirement for dedicated instrumentation. All of these impulses are driving forces for novel research in the area of plasma discharges. Additionally, as known from the field of plasma-related science, the many ways to generate plasma sources are far from being fully exploited analytically, and the fundamentals of conventional sources, which are already in practical use, are far from being completely understood. Also, theoretical modelling is not or is rarely available, analytical performance is often not optimized in routine applications, and reliable hardware (for instance, hardware used for sample introduction) and affordable consumables are lacking. There are thus many reasons why improvements are needed in plasma-based spectroscopy, and why a special issue that focussed on the three following areas, where new trends and innovations were noted by the guest editors, was organized:

Teaching analytical atomic spectroscopy advances in an environmental chemistry class using a project-based laboratory approach: investigation of lead and arsenic distributions in a lead arsenate contaminated apple orchard

Teaching analytical atomic spectroscopy advances in an environmental chemistry class using a project-based laboratory approach: investigation of lead and arsenic distributions in a lead arsenate contaminated apple orchard

Fundamentals of forensic science

Fundamentals of Forensic Science, Second Edition, provides an introduction to the basic principles of forensic science. The book begins at a crime scene and ends in the courtroom. The book is divided into six parts. Part 1 provides an overview of criminal justice and forensic science, covering the basics of crime scene investigation and the nature of evidence. Part 2 discusses analytical tools, including microscopy, Raman spectroscopy, mass spectrometry, atomic spectroscopy, and separation methods. Parts 3 to 5 discuss the various types of forensic evidence collected, categorized by the types of science employed in their analysis: physical science, chemical science, and biological science. These include pathology; anthropology and odontology; entomology; serology and bloodstain pattern analysis; DNA analysis; forensic hair examinations; forensic toxicology; fiber and paint analysis; friction ridge examination; and firearms and tool marks. Part 6 discusses the legal aspects of forensic science. The book is written for students with a background in basic science, and it is can be used in a one-semester or two-semester format. * Vivid, full-color illustrations that diagram key concepts and depict evidence encountered in the field * Straightforward unit organization that includes key terms, numerous feature boxes emphasizing Internet resources, historical events in forensic science, practical issues in laboratory analysis, and topics for further reading * Effective pedagogy, including end-of-chapter questions, paired with a clear writing style makes this an invaluable resource for professors and students of forensic science

Critical evaluation of the application of photochemical vapor generation in analytical atomic spectrometry

Chemical vapor generation (CVG) is a widely adopted sample introduction method for analytical atomic spectrometry. Nonvolatile precursors (usually ionic, metallic or organometallic species) can be transferred from the condensed phase to the gas phase, yielding the advantages of efficient matrix separation, high analyte transport efficiency, high selectivity, simple instrumentation, and ease of automation. Hydride generation enjoys the greatest popularity as a consequence of its ease of implementation, fast reaction and high yield; but photo-CVG, a newly emerging research field in analytical chemistry, may provide a powerful alternative to conventional CVG due to its simplicity, versatility and cost effectiveness. Although photocatalytic pre-reduction has been used for a number of years, the most attractive aspect of this newly emerging area is the direct generation of volatile species using photochemical reactions. Recent studies undertaken with flow through and batch reactors employing low molecular weight organic acids as photochemical agents are highlighted in this study for such systems as mercury and selenium, as well as reaction mechanisms considered for these processes. Discussion is focused on recent advances in photo-CVG, which we believe will become the subject of intensive future research initiatives.

Atomic spectrometry update. Atomic mass spectrometry

This Update is part of a series of annual reviews which cover various aspects of analytical atomic spectrometry. This year’s review follows the same format as last year’s. Although an attempt is made to consider all relevant refereed papers, conference abstracts, reports, book chapters and patents for inclusion, the content of the review is highly selective. The selection of papers is based on criteria applied to focus sharply on the most significant developments in instrumentation and methodology or improved understanding of the fundamental phenomena involved in the MS process. The increasing importance of speciation and the blurring of boundaries between atomic and molecular MS require a high degree of judgement to be made in considering papers for inclusion. The main ruling criterion for all speciation papers is that the work should involve or be intended for the study of natural systems. For example, the study of synthetic metal clusters is generally not included, whereas the determination of organometallic compounds in environmental samples is.

Chemical vapor generation of noble metals for analytical spectrometry

As is apparent from the literature devoted to the analytical atomic spectrometry, chemical vapor generation (CVG) of noble metals by reaction with tetrahydroborate in acidic media may enhance the introduction of these elements into different atomic spectrometric sources. Recent developments in the CVG of noble metals species by reaction with tetrahydroborate in acidic medium are surveyed. Different aspects of this novel technique are discussed, including type of instrumentation used for the reaction, separation and transport of the species, effect of chemical and physical factors, identification of the species, and the efficiency of the process. Limitations and future prospects of the CVG technique are discussed.

Analytical Atomic Spectrometry with Flames and Plasmas

Analytical Atomic Spectrometry with Flames and Plasmas

Vaporization of Pb, As and Ga alone and in the presence of Pd modifier studied by electrothermal vaporization-inductively coupled mass spectrometry

Inductively coupled plasma mass spectrometry (ICP-MS) with electrothermal vaporization (ETV) was used to study the processes taking place in a graphite furnace for atomic spectroscopy. Monitoring of carbon release during the pyrolysis stage provided information on the solid-state reduction processes. Among three carbon species studied ( 12C, 13C and 28CO), 13C was found to be the most suitable. Gallium and arsenic oxides practically do not reduce during the pyrolysis stage. According to the data on carbon release, two reduction processes of lead species (at about 690–915 and > 1000 °C) were found to take place in the furnace. Two separate peaks of Pb (at the end of the pyrolysis stage and in the vaporization stage) were observed, probably related to vaporization of unreduced lead oxide and elemental Pb, respectively. A pre-reduced palladium modifier suppresses the low-temperature Pb losses so that the high-temperature Pb peak is increased. In the absence of modifier, a gaussian-shaped As signal was formed only if small arsenic masses were introduced into the vaporizer. Increase of the arsenic mass resulted in formation of a pronounced plateau after the peak, in spite of the very high vaporization temperature applied (2500 °C). In the presence of pre-reduced palladium modifier, a gaussian-shaped As signal was formed already at 1700 °C with a 4–15-fold increase in sensitivity depending on the analyte mass. The palladium modifier apparently prevents strong interaction of arsenic with graphite. The obtained data support very high potential of ETV-ICP-MS for detailed investigation of processes occurring in graphite furnaces used in analytical atomic spectroscopy, especially during the pyrolysis stage.

Effect of Surfactants on the Behavior of Chromium in Analytical Flame Atomic Absorption Spectrometry

The behavior of surfactants of different natures and chain lengths was studied in flame atomic absorption spectrometry (FAAS) analyses. The variations of absorbance, which arise as a consequence of the surfactant addition to aqueous solutions of Cr(VI) or Cr(III), were measured. Depressions were observed below the critical micelle concentration (CMC), whereas enhancements were observed above the CMC. These depressions are more significant when the surfactant is opposite in charge to the analyte and the longest surfactant chain is used. A mechanism that enables explanation of the effects of a surfactant on FAAS is also suggested. This mechanism is based on the preferential orientation of surfactant molecules to the surface of nebulized droplets.

Development of Gas-Phase Sample-Introduction Techniques for Analytical Atomic Spectrometry

For the last 30 years, several types of gas-phase sample-introduction methods in analytical atomic spectrometry, i.e., atomic absorption spectrometry (AAS), atomic emission spectrometry (AES) and atomic fluorescence spectrometry (AFS), have been investigated and developed in the author's laboratory. Their fundamental results are summarized in this review article. The gas-phase sample-introduction techniques developed in the author's laboratory can be roughly divided into four groups: i) hydride generation, ii) cold-vapor generation of mercury, iii) analyte volatilization reactions and iv) miscellaneous. The analytical figures of merit of the gas-phase sample-introduction methods have been described in detail. Hydride generation has been coupled with the AAS of As, Bi, Ge, Pb, Sb, Se, Sn and Te, with the inductively coupled plasma (ICP) AES of As, Bi, Sn, Se and Sb, with the high-power nitrogen microwave-induced plasma (N2-MIP) AES of As, Bi, Pb, Sb, Se, Sn and Te by their single- and multi-element determinations, with the AFS of As, Bi, Pb, Sb, Se, Sn and Te, and with the ICP mass spectrometry (MS) of As and Se. The cold-vapor generation method for Hg has been combined with atmospheric-pressure helium microwave-induced plasma (He- or Ar-MIP)-AES and AFS. Furthermore, analyte volatilization reactions have been employed in the ICP-AES of iodine, in the He-MIP-AES of iodine bromine, chlorine, sulfur and carbon, and in the ICP-MS of sulfur. As a result, when compared with conventional solution nebulization, a great improvement in the sensitivity has been attained in each instance. In addition, the developed techniques coupled with analytical atomic spectrometry have been successfully applied to the determination of trace elements in a variety of practical samples.

Atomic spectrometry update. Atomic mass spectrometry

This Update is part of a series of annual reviews which cover the various aspects of analytical atomic spectrometry. John Williams has contributed to the ICP-MS section of all 17 of the reviews since the inception of the series in 1988 but is unable to continue to do so. We wish to acknowledge his valuable contribution over the years and to thank him for his efforts. We welcome Kathryn Linge to the writing team in John’s place. This year’s review follows the same format as last year’s but there has been some re-ordering of the sections to reflect the growing importance of ESMS and GC-EIMS for speciation analysis. Although an attempt is made to consider all relevant refereed papers, conference abstracts, reports, book chapters and patents for inclusion in this review, the content of the review is highly selective. The selection of papers is based on criteria applied to focus sharply on the most significant developments in instrumentation and methodology or improved understanding of the fundamental phenomena involved in the MS process. The increasing importance of speciation and the blurring of boundaries between atomic and molecular MS require a high degree of judgement to be made in considering papers for inclusion. The main criterion for selecting speciation papers was that the work should involve or be intended for the study of natural systems. For example, the study of synthetic metal clusters is generally not included, whereas the determination of organometallic compounds in environmental samples is. Applications of atomic MS in other areas are not covered in this Update and readers are referred to the Updates on Industrial Analysis: Metals, Chemicals and Advanced Materials, Environmental Analysis and Clinical and Biological Materials, Food and Beverages. Throughout this review, the term molecular ion will be restricted to denote only the positive or negative radical ion formed by removal or capture, respectively, of an electron. In contrast, addition of a proton or cation to a neutral molecule gives a molecular adduct ion. Deprotonated molecules are considered as fragments. Although reproducibility or precision is a key figure of merit in MS, there is no agreed format for quoting it. The reader can assume that values of precision given in this Update as a percentage correspond to the RSD unless otherwise specified. For isotope ratios, however, values of precision are generally given as the SD of a permil value. It is a widespread phenomenon that analytical techniques in general, and MS in particular, spawn a large number of abbreviations and acronyms. A glossary of all abbreviations used in this Update appears at the end of the review. Most abbreviations are not defined in the text but those which are unlikely to be commonly known are defined in the text when used first and again in the glossary.

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

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.