Assessment of LIBS for Spectrochemical Analysis: A Review

Abstract

This review assesses the applications of laser-induced breakdown spectroscopy (LIBS) for the analysis of a variety of samples, including biomaterials (teeth, nail, hair, gallstones, and kidney stones, etc.), food materials (fruits and vegetables, milk, salt, nutritional supplements, etc.), medicinal plants, industrial waste, liquid samples, etc. In addition, for the first time the identification of cholesterol and pigment stones was performed on the basis of atomic lines of different elements and molecular bands of C₂ molecules present in the LIBS spectra of gallstones. Chemometric techniques such as principal component analysis (PCA) was also applied to LIBS data for rapid identification/classification of different gallstone samples. LIBS analysis of toxic/heavy elements present in vegetables (spinach, tomato) and rice is also presented in this review. It was observed that vegetables grown near industrial areas are rich in several toxic metals like Pb and Cr. The wastewater samples from different industries were also analyzed by recording their spectra using a liquid jet. These results clearly demonstrate the ability of LIBS technique as an instant monitoring device to detect heavy metals present in liquid samples. Finally, this review shows that LIBS is a versatile analytical technique with unlimited applications.

Keywords:

• LIBS
• gallstone
• PCA
• medicinal plants
• industrial waste

Acknowledgment

Financial assistance from the BRNS, BARC, Mumbai (no. 2009/37/30/BRNS/2063), is gratefully acknowledged. We are grateful to Dr. P. K. Rai for providing the gallstone samples and for valuable discussions. We are grateful to Professor B. Rai and N. A. Khan for improving the grammar in this manuscript. Ashok Kumar Pathak is grateful to UGC, New Delhi (No. F.27-99(TF)/2009(NRCB), for granting a teacher fellowship award under the FIP scheme. Rohit Kumar is grateful to BRNS, BARC, Mumbai, for granting a junior research fellowship.

Ashok Kumar Pathak was on leave from the Department of Physics, Ewing Christian College, University of Allahabad, Allahabad, India, at the time this work was performed.