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.

XPS characterisation of in situ treated lanthanum oxide and hydroxide using tailored charge referencing and peak fitting procedures

X-ray photoelectron spectroscopy of rare-earth compounds

The repetitive breakdown spark from a focused laser beam was used to generate analytically useful emission spectra of aerosols in air. The apparatus is simple; a pulsed laser and optics, a spectrometer, and some method for time resolution of the spark light. Time resolution is essential because of the strong continuum emission at early times (<500 ns). High temperatures in the spark result in vaporization of small particles, dissociation of molecules, and excitation of atomic and ionic spectra. The plasma acts as if it were in local thermodynamic equilibrium, at least after 1 ..mu..s. Spectroscopic methods have been used to measure the time-resolved temperatures and electron densities. A simple one-dimensional hydrodynamic model predicts the temperature and diameter of the spark. Beryllium in atmospheric pressure air has been detected at 0.7 ..mu..g/m/sup 3/, which is 0.6 ng/g of air (RSD = 30%). Limits of detection have also been established for Na, P, As, and Hg in air. A calibration curve linear over 4 orders of magnitude has been developed for Na in air. In situ experiments have been performed on two experimental coal gasification systems, and real-time spectral information has been obtained in both cases. 37 references, 9 figures, 2 tables.

Time-resolved laser-induced breakdown spectrometry of aerosols

The nano-sized coupled oxides ZnO/SnO 2 in a molar ratio of 2:1 (Z 2 S) and 1:1 (ZS) were prepared using the co-precipitation method and characterized with X-ray diffraction (XRD), UV–VIS diffuse reflectance spectroscopy and specific surface area (Brunauer–Emmett–Teller (BET)). Their photocatalytic activities were also evaluated using methyl orange (MO) as a model organic compound. The isothermal adsorption behavior of MO on Z 2 S and the factors affecting the photocatalytic activity, such as the heat-treating temperature for the photocatalyst, the pH value of the reaction suspension and the addition of NaCl, KNO 3 and K 2 SO 4 into the suspension, have been studied. It is found that the change in phase of Z 2 S occurs with the calcination temperature. The band gap energy value observed by UV–VIS diffuse reflectance spectroscopy is 3.15 eV for Z 2 S compared with those of 3.12 eV for ZS, 3.17 eV for ZnO and 2.53 eV for SnO 2 . The isothermal adsorption behavior is a two-stage process. The photocatalytic degradation rate of MO on Z 2 S is faster than that on ZS and ZnO by 40.2 and 66.1%, respectively. A schematic diagram of photocatalytic activity is also presented to explain the results.

Preparation, characterization and photocatalytic activity of nano-sized ZnO/SnO2 coupled photocatalysts

Rare earth (RE) halides (fluorides, chlorides, bromides, and iodides) have been studied by X-ray photoelectron spectroscopy. The binding energies (BE’s) of the RE 3d and 4d peaks for the chlorides, bromides, and iodides are related to the atomic charge calculated on the basis of Pauling’s scale of electronegativity (Pauling charge). Except for Y and Lu, the observed RE 3d and 4d BE’s for the fluorides are lower than those expected. For Y and Lu, the observed RE 3d and 4d BE’s for all halides are related to the Pauling charge. For the fluorides and chlorides, the BE’s of the ligand peak show variations with increasing atomic number of RE’s and a specific “tetrad effect” is observed in plots of BE versus RE atomic number and versus 1/R (where R is the mean distance from the ligand atom to the neighboring RE atom), except for the BE’s of the F 1s peaks from the light RE fluorides. For the iodides and bromides, no or little characteristic variations are seen in the BE’s of I and Br.

X-Ray Photoelectron Spectroscopy of Rare Earth Halides

A laser vaporization-microwave induced plasma system was used for the determination of various elements in solid samples such as brass, steel, and aluminum alloy. The emission signals of Al, Cr, Cu, Fe, Mn, Mo, Ni, Pb, Tl, and Zn were traced with an oscilloscope, and those elements were determined with high-speed peak-holder and integrator. Precision (relative standard deviation) was 1.2% to 13.8% for the peak-height method, and 2.3% to 12.1% for the peak-area method. The detection limits in the solid samples ranged from 0.9 ppM (0.7 pg) for Zn in aluminum alloy to 22 ppM (20 pg) for Mo in steel. 9 figures, 2 tables.

Yoshinori Uwamino

Papers

X-ray photoelectron spectroscopy of rare-earth compounds

X-Ray Photoelectron Spectroscopy of Rare Earth Halides

Atomic emission spectrometry of solid samples with laser vaporization-microwave induced plasma system

Laser-vaporized atomic absorption spectrometry of solid samples

Charge correction by gold deposition onto non-conducting samples in X-ray photoelectron spectroscopy