The first part of this two-part review focused on the fundamental and diagnostics aspects of laser-induced plasmas, only touching briefly upon concepts such as sensitivity and detection limits and largely omitting any discussion of the vast panorama of the practical applications of the technique. Clearly a true LIBS community has emerged, which promises to quicken the pace of LIBS developments, applications, and implementations. With this second part, a more applied flavor is taken, and its intended goal is summarizing the current state-of-the-art of analytical LIBS, providing a contemporary snapshot of LIBS applications, and highlighting new directions in laser-induced breakdown spectroscopy, such as novel approaches, instrumental developments, and advanced use of chemometric tools. More specifically, we discuss instrumental and analytical approaches (e.g., double- and multi-pulse LIBS to improve the sensitivity), calibration-free approaches, hyphenated approaches in which techniques such as Raman and fluorescence are coupled with LIBS to increase sensitivity and information power, resonantly enhanced LIBS approaches, signal processing and optimization (e.g., signal-to-noise analysis), and finally applications. An attempt is made to provide an updated view of the role played by LIBS in the various fields, with emphasis on applications considered to be unique. We finally try to assess where LIBS is going as an analytical field, where in our opinion it should go, and what should still be done for consolidating the technique as a mature method of chemical analysis.

https://journals.sagepub.com/doi/pdf/10.1366/11-06574

Laser-induced breakdown spectroscopy (LIBS), part II: review of instrumental and methodological approaches to material analysis and applications to different fields.

■ 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 become a very popular analytical method in the last decade in view of some of its unique features such as applicability to any type of sample, practically no sample preparation, remote sensing capability, and speed of analysis The technique has a remarkably wide applicability in many fields, and the number of applications is still growing From an analytical point of view, the quantitative aspects of LIBS may be considered its Achilles' heel, first due to the complex nature of the laser–sample interaction processes, which depend upon both the laser characteristics and the sample material properties, and second due to the plasma–particle interaction processes, which are space and time dependent Together, these may cause undesirable matrix effects Ways of alleviating these problems rely upon the description of the plasma excitation-ionization processes through the use of classical equilibrium relations and therefore on the assumption that the laser-induced 

Laser-Induced Breakdown Spectroscopy (LIBS), Part I: Review of Basic Diagnostics and Plasma–Particle Interactions: Still-Challenging Issues Within the Analytical Plasma Community

/pdf/modification-and-preservation-of-environmental-signals-in-3icv6ero3u.pdf

Modification and preservation of environmental signals in speleothems

Occurrence and removal of transformation products of PPCPs and illicit drugs in wastewaters: a review.

Laser-induced plasma spectrometry: truly a surface analytical tool

The ablation rate expressed as the amount of removed material per laser shot was calculated for pure metal samples under different experimental conditions: laser fluence (1.3‐16.7 J cm 2 ), buffer gas (air, He and Ar) and gas pressure (10 3 ‐10 5 mbar). Fluence values covered the range between the plasma threshold (~1‐2 J cm 2 for most elements) and 16.7 J cm 2 . The 581 nm output of an excimer-pumped dye laser was used. Results pointed out a strong dependence of ablation rate on experimental parameters. At high fluence, the ablated material efficiently attenuates the incoming laser radiation (plasma shielding) and reduces the ablation rate. The extent of this shielding effect depend also on the experimental variables (buffer gas, pressure) and sample nature. These studies are useful to determine the amount of ablated material as a function of experimental parameters, to understand the extension of the shielding process and to establish the conditions under which it may be avoided. Copyright ” 1999 John Wiley & Sons, Ltd.

http://atarazanas.sci.uma.es/docs/articulos/1669014x.pdf

Effect of plasma shielding on laser ablation rate of pure metals at reduced pressure

The spatial profile from an XeCl excimer laser was modified using a simple two-lenses telescope to generate a flat energy-profile beam that impinged a layered sample (a Zn-coated steel) without beam conditioning. The irradiance obtained (about 107 W cm–2) was high enough to vaporize the target, to cause plasma formation and to allow atomic emission spectrometry with acceptable signal-to-noise ratio. Modification in beam energy distribution resulted in flat ablated profiles and improved depth-resolution up to the few nm pulse–1 range was attained. The net intensity areas were transformed into normalized values leading to plots in excellent agreement with those provided by commercial depth-resolved analysis instruments.

http://atarazanas.sci.uma.es/docs/articulos/16723971.pdf

Nanometric range depth-resolved analysis of coated-steels using laser-induced breakdown spectrometry with a 308 nm collimated beam

The use of laser-induced breakdown spectrometry for spatial distribution analysis of platinum, rhodium, and palladium in car catalytic converters is discussed. Fresh converters were extracted from the car exhaust system, cut in pieces of an appropriate size, and analyzed for mapping purposes. Spectral detection, pulse energy, and beam focal conditions were optimized according to the ablation behavior of the material. Difficulties in distribution analysis caused by the complex elemental composition of the sample were overcome by an extensive spectral analysis using appropriate internal standards. Data on the spatial distribution of the active metals in both the axial and radial directions of the catalytic structures are presented.

http://atarazanas.sci.uma.es/docs/articulos/16690631.pdf

Mapping of platinum group metals in automotive exhaust three-way catalysts using laser-induced breakdown spectrometry.

The capability of laser-induced breakdown spectrometry (LIBS) to
resolve complex depth profiles is demonstrated. Electrolytically deposited
brass samples were analyzed by monitoring the emission corresponding to Cr
(357.8 nm), Ni (341.4 nm), Cu (327.4 nm) and Zn (334.5 nm). The nominal
thickness of the layers was known, which permitted an estimate of the
ablated mass in the range between 150 and 500 nm per pulse depending on
the matrix and laser irradiance. Laser irradiance was varied by
defocusing, and its effect on the depth-resolution of LIBS was tested. For
comparison purposes, a commercial zinc-coated steel was also studied by
following the Zn and Fe emission intensity depth profiles with a
commercial glow-discharge optical emission spectrometry system to obtain
information on the exact location of the Zn–Fe interface (12 µm).
The ablation rate in terms of ablated mass per pulse was found to be at
the ng per pulse level and depended on the laser pulse
irradiance.

http://www.biblioteca.uma.es/bbldoc/articulos/16719797.pdf

José M. Vadillo

Papers

Laser-induced plasma spectrometry: truly a surface analytical tool

Effect of plasma shielding on laser ablation rate of pure metals at reduced pressure

Nanometric range depth-resolved analysis of coated-steels using laser-induced breakdown spectrometry with a 308 nm collimated beam

Mapping of platinum group metals in automotive exhaust three-way catalysts using laser-induced breakdown spectrometry.

Depth-resolved Anaylsis of Multilayered Samples by Laser-inducedBreakdown Spectrometry