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.

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 plasma is in local thermodynamic equilibrium (LTE). Even in this case, the transient nature of the plasma and its spatial inhomogeneity need to be considered and overcome in order to justify the theoretical assumptions made. This first article focuses on the basic diagnostics aspects and presents a review of the past and recent LIBS literature pertinent to this topic. Previous research on non-laser-based plasma literature, and the resulting knowledge, is also emphasized. The aim is, on one hand, to make the readers aware of such knowledge and on the other hand to trigger the interest of the LIBS community, as well as the larger analytical plasma community, in attempting some diagnostic approaches that have not yet been fully exploited in LIBS.

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The "super stars" of analytical spectrometry, ETA-AAS, ICP-AES, and ICP-MS, are compared to the other atomic spectrometric methods. LIBS will be emphasized with regard to its figures of merit with regard to its disadvantages and advantages.

Deconvolution of composite fluorescence spectra and related decay curves for Uv' in the pH ranges &5 and 9-1 1 at different total U concentrations, yielded decay times and individual fluorescence spectra for various hydroxocomplexes (U02),(0H),c2" '-") , where (m, n ) = (1, 1); (1, 3); (2, 2) and (3, 5). Depending on the emission wavelength, the fluorescence efficiencies of (2, 2) and (3, 5) were found to be, respectively, 7 to 85, and 3 to 4 times higher than that of t h e uranyl ion, whereas the latter is ca. 3 times more fluorescent than t h e (1, 1) complex. Thus, relatively small concentrations of polynuclear species contribute appreciably to t h e overall fluorescence of aqueous Uv' solutions. The fairly large difference between decay times and the high sensitivity of t h e equipment used made it possible to detect even small amounts of t h e hydroxo complexes. In the alkaline pH range 10-12, t h e (1, 3) hydroxo-complex was found to predominate. In t h e presence of 0.05 mol dm-3 phosphate and in the same pH range, there was a pronounced change in the fluorescence spectrum indicating that the chemical speciation in the system had changed. These observations make it necessary to revise the current equilibrium data for uranium(v1) phosphate complexes at high pH.