Laser-induced breakdown spectroscopy LIBS technique

Vukjovic et al.199 recently proposed a simple, fast, sensitive, and low-cost procedure based on solid phase spectrophotometric (SPS) and multicomponent analysis by multiple linear regression (MA) to determine traces of heavy metals in pharmaceuticals. Other spectroscopic techniques employed for high-throughput pharmaceutical analysis include laser-induced breakdown spectroscopy (LIBS),200 201 fluorescence spectroscopy,202 204 diffusive reflectance spectroscopy,205 laser-based nephelometry,206 automated polarized light microscopy,207 and laser diffraction and image analysis.208... 

The emerging analytical technique of laser-induced breakdown spectroscopy (LIBS) is a simple atomic emission spectroscopy technique that has the potential for real-time man-portable chemical analysis in the field. Because LIBS is simultaneously sensitive to all elements, a single laser shot can be used to record the broadband emission spectra, which provides a chemical fingerprint of a material. 

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. 

Another micro-destructive technique is laser-induced breakdown spectroscopy (LIBS) which is used to analyse the paint layers. Nanosecond laser pulses vaporise a small amount of material from the surface of the painting and the amounts so lost are only 50 billionths of a gram and too small to be seen with the naked eye. The vapour passes between two high-voltage electrodes which excite the atoms and these then emit a pattern of light energy bands which identify the elements. LIBS together with Raman spectroscopy has been used to examine Russian icons which are multilayered. 

Laser-induced breakdown spectroscopy (LIBS) features various assets and shortcomings worth considering in adopting it as the technique of choice for specific applications. The most salient advantages of LIBS for spectrochemical analysis are as follows ... 

In recent years, the laser has beconie very useful in aiomic emission spectroscopy. We con.sider here two lascr-ba.sed techniques laser microprohe spcclroscopy and laser-induced breakdown spectroscopy (LIBS). 

Understanding how nanoenergetic materials are both made and consumed requires the ability to monitor these processes widi real time in-situ diagnostic techniques. Laser Induced Breakdown Spectroscopy (LIBS) is an optical technique that can detect all the elements simultaneously from very small sanq>les of material. Only four elements are needed to implement this technique an excitation source, delivery and collecting optics, a detector with wavelength dispersion capability, and a conqtuter for control and anal is. Because of these relatively sinq>le requirements, a conq>lete LIBS system can be made contact, rugged, and fairly ine q>ensively. Spectrometers are now becoming commercially... 

Laser-induced breakdown spectroscopy (LIBS) is a relatively new atomic emission spectroscopy technique that uses a pulsed laser as the excitation sonrce. LIBS is also referred to as laser spark spectroscopy (LASS) and laser-induced plasma spectroscopy, with the unfortunate acronym of LIPS. The technique was developed in the early 1960s, after the invention of the laser, but the high cost and large size of lasers and spectrometers made this a specialized research tool until the 1990s. The early development of LIBS is covered in the reference by Myers et al. Recent advances... 

All major modem atomic absorption and emission techniques and instrumentation are covered, including new MP-AES and triple quadrupole ICP-MS instruments. The relatively new technique of laser-induced breakdown spectroscopy (LIBS) has been added to Chapter 7 and is now currently being used on Mars in the Curiosity rover, which landed on the Red Planet in August 2012. Appendices with EAAS and GEAAS conditions have been added, and the appendix with limits of detection for all the atomic spectroscopic techniques has been updated from the sixth edition. The chapter on X-ray has been significantly revised by Dr. Alexander Seyfarth, the new coauthor of the chapter, to reflect the state of the art in XRP, XRD, and related techniques. Many new graphics have been added. 

The methods most widely in use now for understanding and monitoring chemical processes that affect our environment and the atmosphere are those of TDLAS, and remote absorption/Raman spectroscopy based on lidar (absoiption-Hdar/ Raman-lidar). Application examples of these two techniques are outlined in Sections 28.1—28.3 and Sections 28.4-28.6 respectively. The chapter will conclude with the description of some less-developed techniques, which, however, provide information not easily obtained, or not accessible at all. All of them are based on ionization in one form or other, and include laser-induced breakdown spectroscopy (LIBS), matrix-assisted laser desorption ionization (MALDl) and aerosol TOFMS (ATOFMS). Examples of these are provided in Section 28.7. 

The same equipment, which is used for time-resolved luminescence application is suitable for other laser-based spectroscopies. Thus several spectroscopic methods may be applied simultaneously. The mostly important technique, which may be used together with time-resolved luminescence, is laser-induced breakdown spectroscopy. Several books have been recently published devoted to Laser Induced Breakdown Spectroscopy (LIBS) (Cremers and Radziemski 2013 Miziolek et al. 2006 Singh and Thakur 2007 Noll 2012 Hahn and Omenetto 2010 Hahn and Omenetto 2012). LIBS aspects were considered applied to the analysis of minerals, rocks and related materials (Senesi 2014). Thus only the theoretical aspects which are the mostly relevant to our research devoted to the real time online quality control of minerals will be considered. 

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. 

In recent years, several groups have proposed the use of Laser Induced Breakdown Spectroscopy as a technique capable of giving information on the pigment compositions with minimal damage of the artwork. However, until the development of quantitative methods for accurate elemental analysis, the LIBS technique was hardly competitive with other methods for quantitative analysis of the samples. 

During the last decade, processing of polymers has become an important field of applied and fundamental research [48]. One of the most important fields is laser ablation involving various techniques and applications. Laser ablation is used as an analytical tool for MALDI (matrix-assisted laser de-sorption/ionization) [28, 29] and LIBS (laser-induced breakdown spectroscopy) [49] or as a preparative tool for PLD (pulsed laser deposition) of inorganic materials [37] and of synthetic polymer films [50, 51]. Another application is surface modification of polymers [52] if low fluences are applied, the polymer surface can be either chemically modified to improve adhesion... 

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. 

Different analytical techniques are used for detection of the elemental composition of the solid samples. The simplest is direct detection of emission from the plasma of the ablated material formed above a sample surface. This technique is generally referred to as LIBS or LIPS (laser induced breakdown/plasma spectroscopy). Strong continuous background radiation from the hot plasma plume does not enable detection of atomic and ionic lines of specific elements during the first few hundred nanoseconds of plasma evolution. One can achieve a reasonable signal-to-noise ra-... 

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