**4. Conclusion**

160 Advanced Aspects of Spectroscopy

across the sample.

constitute pixels on left map.

d. Ceramic and geology sample application

Laser induced plasma spectroscopy has been applied to the analysis of element distribution mapping of polished rock sections[40]. The plasma was generated by focusing a frequencydoubled second harmonic 532 nm Nd:YAG laser on the target under atmospheric conditions. The experimental parameters, such as laser energy, atomic emission line and time profile of the plasma spectrum, were characterized to obtain optimum experimental conditions and estimate the element composition of the target surface. For the element mapping of samples, an X-Y stage was used to move the sample and an element image of 50 x 50 mm could be made in 30 min. Using this technique, the element concentration distribution of Ba, Cu, Fe, Mn, Pb, Si, and Sr in polished rock sections were obtained. Quantitative analysis was achieved by analyzing standard rock samples. Calibrated concentration versus plasma intensity was used for the color grading for the mapping of element concentration distribution. The elemental mapping analysis for a granite sample is illustrated in Figure 26. The ore vein within the existing sample was selected to identify the different compositions of ore and surface element distribution. The element distribution differences were represented by color grading, where the upper first line represents the color scale. The region where a lode was crossed during the analysis is rich in Pb and Sr but the Ba content is low. Iron does not show differences and is nearly uniformly distributed

**Figure 27.** The mapping image of a commercial printed circuit board. Black circle and character on the right circuit board is copper layer for soldering electronic component. The measured values from LIBS

A sensitive optical technique for compositional mapping of solid surface using LIBS was described[41]. A pulsed Nd:YAG laser with second harmonic module was focused on the solid surface, giving a small ablation area, to produce plasma emission. Copper and magnesium emissions from a standard sample were carefully analyzed and assigned in the wavelength range 500-520 nm. The assigned spectral information was selected to construct an image of 100 x 100 pixels by mapping the measured emission intensity values from the analyzed points. The time required for image construction and image sharpness depends on The goal of LIBS development is to extend the analytical feasibility of LIBS for detecting organic, inorganic metals and ceramic material for the various applications. The sample types also not limited to the solid and expanded to liquid gas, aerosol, powder, bacteria, and industrial products. Several applications of LIBS were illustrated in this chapter. Detections for metallic components are usually accomplished easily from the measured spectral ranges from ultraviolet (230 nm) to visible (700 nm) of the plasma emission. Only a few seconds of measuring time is a great advantage and will be useful for screening and monitoring system for industry and security monitoring. Evaluation of analytical feasibility for detecting and identifying the sample should be decided by analyzing the LIBS spectra of specific components as well as matrix derived from the source of the samples.
