Effects of laser focusing and fluence on the analysis of pellets of plant materials by laser-induced breakdown spectroscopy

Author(s)

Arantes de Carvalho, Gabriel Gustinelli ^[1] ; Santos Junior, Dario ^[2] ; Nunes, Lidiane Cristina ^[1] ; Gomes, Marcos da Silva ^[3] ; Leme, Flavio de Oliveira ^[1] ; Krug, Francisco Jose ^[1]

Affiliation

^[1] Univ Sao Paulo, Ctr Energia Nucl Agr, BR-13416000 Piracicaba, SP - Brazil

^[2] Univ Fed Sao Paulo UNIFESP, BR-09972270 Diadema, SP - Brazil

^[3] Univ Fed Sao Carlos, Dept Quim, BR-13565905 Sao Carlos, SP - Brazil

• Document type: Journal article
• Source: SPECTROCHIMICA ACTA PART B-ATOMIC SPECTROSCOPY; v. 74-75, p. 162-168, AUG-SEP 2012.
• Web of Science Citations: 17

Abstract

The effects of laser focusing and fluence on LIBS analysis of pellets of plant leaves was evaluated. A Q-switched Nd:YAG laser (5ns, 10Hz, 1064nm) was used and the emission signals were collected by lenses into an optical fiber coupled to a spectrometer with Echelle optics and ICCD. Data were acquired from the accumulation of 20 laser pulses at 2.0 mu s delay and 5.0 mu s integration time gate. The emission signal intensities increased with both laser fluence and spot size. Higher sensitivities for Ca, K, Mg, P, Al, B, Cu, Fe, Mn, and Zn determinations were observed for fluences in the range from 25 to 60Jcm(-2). Coefficients of variation of site-to-site measurements were generally lower than 10% (n=30 sites, 20 laser pulses/site) for a fluence of 50Jcm(-2) and 750 mu m spot size. For most elements, there is an indication that accuracy is improved with higher fluences. (C) 2012 Elsevier B.V. All rights reserved. (AU)

• FAPESP's process: 10/16379-0 - Sampling strategies for analysis of biological materials by laser induced breakdown spectrometry
• Grantee: Gabriel Gustinelli Arantes de Carvalho
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 10/17158-8 - Evaluation of laser induced breakdown spectrometry (LIBS) for determination of inorganic contaminants in agricultural fertilizers
• Grantee: Lidiane Cristina Nunes
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 04/15965-2 - Implementation and development of Laser Induced Breakdown Spectroscopy (LIBS)
• Grantee: Francisco José Krug
• Support Opportunities: Research Projects - Thematic Grants