Laser-Induced Breakdown Spectrometry LIBS

The main factor in beam analysis that affects the reliability of the analytical information is the reproducibility of the surfaces. When using scanning electron microscopy (SEM), the apparati are connected to the computer, which makes it possible to obtain quite a bit of information about the sample, especially by X-ray and AES. However, the apparati cannot assure the same length for beam penetration on the surface, which means that the analytical information can be uncertain. Because the beam analysis is rapid, it requires very fast detectors, e.g., Ge/Li or Si/Li. The LA can be successfully used in surface analysis. An automated system has been constructed, laser-induced breakdown spectrometry (LIBS).213 This is an alternative to other surface techniques — secondary ion mas spectroscopy (SIMS), SEM, X-ray photoelectron spectroscopy (XPS) — and it increases the lateral and depth resolution. 

A more suitable approach for on-line analysis is to view atomic emission directly from the small plasma formed above the sample surface when the sample is ablated using the laser. This approach, which is shown schematically in Fig. 20.12 has been applied to analyses of a variety of materials (e.g. [58-74]) and is known under a variety of names such as laser induced plasma spectrometry (LIPS), laser induced breakdown spectrometry (LIBS) and laser spark emission spectrometry (LASS). The laser used is typically a Nd YAG laser operating either at its fundamental, doubled or quadrupled frequency, although excimer and CO2 lasers have also been used. The important parameter of the laser is that it must be capable... 

The second approach named laser-induced breakdown spectrometry (LIBS) is based on atomic emission spectroscopy. In this method, a laser is focused on a solid sample and forms a microplasma that emits light characteristics of the elemental composition of the sample. The emitted light is collected, spectrally resolved, and detected to monitor concentrations of elements via their unique spectral signatures. When calibrated, the method can also provide quantitative measurements. 

Frequently, laser-induced breakdown spectrometry (LIBS) requires multivariate regression to solve complex problems. The first paper that was found dates back to 2000 and was related to jewellery studies. Amador-Hernandez et al. showed that PLS models were highly satisfactory for measuring Au and Ag in Au-Ag-Cu alloys. This study was further completed by Jurado-Lopez and Luque de Castro, who compared the hybridized LIBS-PLS technique with analytical scanning microscopy, ICP-OES, FAAS and LIBS. Although the... 

Three techniques with spatially resolved information capabilities have been selected here for some further explanation EPXMA, laser-induced breakdown spectroscopy (LIBS) and glow discharge optical emission spectrometry (GD-OES). Figure 1.15 summarises the lateral and depth resolution provided by the techniques described in this section. It is worth noting that the closer to the bottom left corner the technique is located, the higher (and so better) is the depth resolution. 

Spectral methods based on UV-visible spectrophotometry, laser-induced breakdown spectroscopy (LIBS), infrared (IR), Raman, nuclear magnetic resonance (NMR) spectroscopy, mass spectrometry (MS), thermoanalytical and chromatographic methods, especially liquid chromatography (LC) or gas chromatography (GC) combined with pyrolysis are most common. 

LIBS Laser-induced breakdown spectrometry (analytical device)... 

Principles and Characteristics Simultaneous multi-element analysis based on emission from a plasma generated by focussing a powerful laser beam on a sample (solid, liquid, or gas) is known as laser-induced breakdown spectroscopy (LIBS) and under a variety of semantic variations time-resolved LIBS (TRELIBS), laser ablation emission spectroscopy (LAES), laser ablation atomic emission spectrometry (LA-AES), laser ablation optical emission spectrometry (LA-OES), laser plasma emission spectrometry (L-PES), laser-induced plasma spectroscopy (LIPS), laser spark spectroscopy (LSS), and laser-induced emission spectral analysis (LIESA ). Commercial LIBS analysers were already available in the 60/70s the technique now enjoys a renaissance. 

This presentation will summarize developments in laser ablation with emphasis on LIBS (laser induced breakdown spectroscopy) and inductively coupled plasma mass spectrometry (ICPMS) as analytical tools for real time chemical analysis (Fig. 1) (Russo et al. 

The technique based on laser-induced breakdown coupled to mass detection, which should thus be designated LIB-MS, is better known as laser plasma ionization mass spectrometry (LI-MS). The earliest uses of the laser-mass spectrometry couple were reported in the late 1960s. Early work included the vaporization of graphite and coal for classifying coals, elemental analyses in metals, isotope ratio measurements and pyrolysis [192]. Later work extended these methods to biological samples, the development of the laser microprobe mass spectrometer, the formation of molecular ions from non-voIatile organic salts and the many multi-photon techniques designed for (mainly) molecular analysis [192]. 

LIBS Laser-induced breakdown (plasma) spectrometry... 

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