■ CONTENTS General Information: Books, Reviews, and Conferences 640 Fundamentals 641 Interaction of Laser Beam with Matter 641 Factors Affecting Laser Ablation and LaserInduced Plasma Formation 642 Influence of Target on the Laser-Induced Plasmas 642 Influence of Laser Parameters on the LaserInduced Plasmas 643 Laser Wavelength (λ) 643 Laser Pulse Duration (τ) 643 Laser Pulse Energy (E) 645 Influence of Ambient Gas on the Laser-Induced Plasmas 645 LIBS Methods 647 Double Pulse LIBS 647 Femtosecond LIBS 651 Resonant LIBS 652 Ranging Approaches 652 Applications 654 Surface Inspection, Depth Profiling, and LIBS Imaging 654 Cultural Heritage 654 Industrial Analysis 655 Environmental Monitoring 656 Biomedical and Pharmaceutical Analysis 658 Security and Forensics 659 Analysis of Liquids and Submerged Solids 660 Space Exploration and Isotopic Analysis 662 Space Exploration 662 Isotopic Analysis 662 Conclusions and Future Outlook 663 Author Information 664 Corresponding Author 664 Notes 664 Biographies 664 Acknowledgments 664 References 664

Laser-induced breakdown spectroscopy.

Laser-induced breakdown spectroscopy (LIBS) has been regarded as a future superstar for chemical analysis for years due to its unique features such as little or no sample preparation, remote sensing, and fast and multi-element analysis. Chinese LIBS community is one of the most dynamically developing communities in the World. The aim of the work is to inspect what have been done in China for LIBS development and, based on the understanding of the overall status, to identify the challenges and opportunities for the future development. In this paper, the scientific contributions from Chinese LIBS community are reviewed for the following four aspects: fundamentals, instrumentation, data processing and modeling, and applications; and the driving force of LIBS development in China is analyzed, the critical issues for successful LIBS application are discussed, and in our opinion, the potential direction to improve the technology and to realize large scale commercialization in China is proposed.

Laser-induced breakdown spectroscopy in China

https://pure.hw.ac.uk/ws/files/15477101/1_s2.0_S0166516217302100_main.pdf

Coal-derived unburned carbons in fly ash: A review

This is the 30th annual review of the application of atomic spectrometry to the chemical analysis of environmental samples. This Update refers to papers published approximately between August 2013 and July 2014 and continues the series of Atomic Spectrometry Updates (ASUs) in environmental analysis that should be read in conjunction with other related ASUs in the series, namely: clinical and biological materials, foods and beverages, advances in atomic spectrometry and related techniques, elemental speciation,X-ray fluorescence spectrometry, and the analysis of metals, chemicals and functional materials. In the field of air analysis, highlights within this review period included: the use of 3D printing technology for the rapid prototyping of new air sampler components; single particle ICP-MS studies; use of a new triple-quadrupole ICP-MS for the analysis of radioactive species and the use of FEG-SEM and IBA for the analysis of gun-shot residues. In the field of water analysis, methods continue to be developed: for the extraction and preconcentration of elements; speciation of As, Cr, Hg and Sb forms and determination of elemental constituents in colloidal and NP fractions. Instrumental developments reported include the use of MC-ICP-MS for isotopic tracer studies and a review of XRF techniques and associated preconcentration procedures for trace element analysis. Many articles featuring the analysis of plants and soils appeared but, as usual, most focused on environmental applications rather than the advancement of atomic spectrometry. There have, however, been interesting developments, such as the almost bewildering increase in types of micro-extraction for analyte preconcentration and the resurgence of CS-AAS. Clearly LIBS is maturing rapidly, with soil analysis becoming more routine in nature. Also notable was the way the accident at the Fukishima-Daiichi nuclear power plant triggered development of analytical methods for the assessment of contamination in the surrounding area. Recent research indicates that geological applications still drives many of the instrumental and methodological advances in LA-ICP-MS. Fundamental studies continue to shed light on the processes involved and hence ways of improving the analysis of laser-produced aerosols. The preparation of NP powders for the production of matrix-matched RMs for microanalytical techniques such as LA-ICP-MS and SIMS showed great promise for addressing one of the major issues when analysing geological materials by these techniques. Steady advances in MC-ICP-MS methodology is feeding through to applications in isotope geochemistry, while new SIMS instrumentation is being directed towards probing fine growth structures in biogenic carbonates and inferring past climate conditions from their geochemistry. Feedback on this review is most welcome and the review coordinator can be contacted using the email address provided.

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Atomic spectrometry update – a review of advances in environmental analysis

Coal is one of the world's most abundant primary energy sources. Real-time coal analysis technology is imperative for coal blending, combustion optimization, pollution reduction, and pricing. Laser-induced breakdown spectroscopy (LIBS) has been a promising candidate for coal analysis because of its uniquely fast, in situ, and online capabilities. Coal is a sedimentary rock with a complex and heterogeneous composition, and therefore, laser–coal interaction exhibits multiple phenomena. A systematic study of the experimental conditions required for stable coal–plasma formation and evolution is a headway for enhancing LIBS results. In coal-fired power plants, LIBS offers three installation sets, namely, inline, at-line, and offline, with minimal space requirements and ease of retrofit. Moreover, LIBS is a safer technique with lower installation and maintenance costs and fits the concern of coal-fired power plants for multielemental detection in fast records. Coal analysis mainly includes calorific heat value determination, proximate analysis, ultimate analysis, and other related analyses. LIBS data is handled with continuously developing mathematical and statistical modeling techniques to provide the smart extraction of the required spectral information for coal analysis. In this tutorial review, we summarize the previous research contributions utilizing LIBS for coal analysis, including fundamentals and key factors, operation modes, data processing, and analytical results. Over and above, LIBS contribution in fly ash analysis and certain literature concerning combustion diagnostics might be included to present a simple guideline for researchers interested in LIBS applications for coal utilization.

Coal analysis by laser-induced breakdown spectroscopy: a tutorial review

This paper presents an alternate calibration method for measurement of the unburned carbon (UC) in fly ash using laser-induced breakdown spectroscopy (LIBS). Fly ashes studied in this research were produced from pulverized coal in a muffle furnace and the UC was determined by a loss-on-ignition (LOI) test. We apply both univariate calibration and multivariate calibration methods to LIBS data to establish the calibration curve of the UC in measured samples, and the performance of these two approaches was compared. Our analysis shows that traditionally used univariate calibration in LIBS does not qualify quantitative analysis of fly ashes from different kinds of coal due to the presence of matrix effects. Instead, multivariate calibration has a better performance as the matrix effects can be taken into account with the influence of the spectroscopic signals of other components in fly ash. The correlation coefficients R2 of multivariate calibration reach 0.994 (fly ashes from one kind of coal) and 0.981 (fly ashes from different kinds of coal), which is significantly improved compared with univariate calibration.

Analyzing unburned carbon in fly ash using laser-induced breakdown spectroscopy with multivariate calibration method

Laser-induced breakdown spectroscopy (LIBS) was employed to directly analyze coal particles in the form of descending flow. Coal-particle ablation was performed using a 1064 nm neodymium-doped yttrium aluminum garnet (Nd : YAG) laser at atmospheric conditions. Spectral identification schemes were used to acquire spectra containing all the emission lines of the important elements in coal. These acquired spectra were classified as representative spectra. The background of the line emission plus three times the standard deviation of the background of the representative spectra was chosen as the threshold value. A method using a single line and a method using combined multiple lines (C, 247.8 nm; N, 746.8 nm; Si, 288.2 nm; and Ca, 396.8 nm) were compared to obtain the best results for the spectral identification of coal particle flow. The feasibility of rejecting the partial breakdown spectra was verified using quantitative analysis of fixed carbon in coal.

Experimental study of laser-induced breakdown spectroscopy (LIBS) for direct analysis of coal particle flow.

Optimization of laser-induced breakdown spectroscopy for coal powder analysis with different particle flow diameters

The logical range of laser power density and optimum laser power density were explored for multi-element analysis of pulverized coal flow with laser-induced breakdown spectroscopy in the present paper. The range of laser energy was chosen from 20 to 160 mJ in the experiment. Pulverized coal less than 200 microm in diameter of particles fell freely through feeder outlet and the rate of flow was controlled by screw feeder. Emissions were collected with pulse laser at 1 064 nm focusing on pulverized coal flow and plasma was generated. The intensity and cause of fluctuation of emission spectra at various laser energy levels were studied. A suitable range of laser power density is from 14.4 to 34.4 GW x cm(-2), and the optimum laser power density is 19.5 GW x cm(-2) for the determination of pulverized coal flow with LIBS.

Jianping Zheng

Papers

Analyzing unburned carbon in fly ash using laser-induced breakdown spectroscopy with multivariate calibration method

Experimental study of laser-induced breakdown spectroscopy (LIBS) for direct analysis of coal particle flow.

Optimization of laser-induced breakdown spectroscopy for coal powder analysis with different particle flow diameters

[Study of laser energy in multi-element detection of pulverized coal flow with laser-induced breakdown spectroscopy].