Determination of silicon in plant materials by laser-induced breakdown spectroscopy

Author(s)

de Souza, Paulino Florencio ^{[1, 2]} ; Santos Junior, Dario ^[3] ; Arantes de Carvalho, Gabriel Gustinelli ^[1] ; Nunes, Lidiane Cristina ^[1] ; Gomes, Marcos da Silva ^{[4, 1]} ; Bueno Guerra, Marcelo Braga ^[1] ; Krug, Francisco Jose ^[1]

Affiliation

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

^[2] Ctr Tecnol Canavieira, BR-13400970 Piracicaba, SP - Brazil

^[3] Univ Fed Sao Paulo, Dept Ciencias Exatas & Terra, BR-09972270 Diadema, SP - Brazil

^[4] Univ Fed Sao Carlos, Dept Quim, BR-13565905 Sao Carlos, SP - Brazil

• Document type: Journal article
• Source: SPECTROCHIMICA ACTA PART B-ATOMIC SPECTROSCOPY; v. 83-84, p. 61-65, MAY-JUN 2013.
• Web of Science Citations: 24

Abstract

In spite of the importance of Si for improving the productivity of many important crops, such as those from the Poaceae family (e.g. sugar cane, maize, wheat, rice), its quantitative determination in plants is seldom carried out and restricted to few laboratories in the world. There is a survey of methods in the literature, but most of them are either laborious or difficult to validate in view of the low availability of reference materials with a certified Si mass fraction. The aim of this study is to propose a method for the direct determination of Si in pellets of plant materials by laser-induced breakdown spectroscopy (LIBS). The experimental setup was designed by using a Q-switched Nd:YAG laser at 1064 nm (5 ns, 10 Hz) and the emission signals were collected by lenses into an optical fiber coupled to an Echelle spectrometer equipped with an intensified charge-coupled device. Experiments were carried out with leaves from 24 sugar cane varieties, with mass fractions varying from ca. 2 to 10 g kg(-1) Si. Pellets prepared from cryogenically ground leaves were used as test samples for both method development and validation of the calibration model. Best results were obtained when the test samples were interrogated with laser fluence of 50 J cm(-2) (750 mu m spot size) and measurements carried out at Si I 212.412 nm emission line. The results obtained by LIBS were compared with those from inductively coupled plasma optical emission spectrometry after oven-induced alkaline digestion, and no significant differences were observed after applying the Student's t-test at 95% confidence level. The trueness of the proposed LIBS method was also confirmed from the analysis of CRM GBW 07603 (Bush branches and leaves). (c) 2013 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: 12/16203-5 - Strategies for the direct analysis of sugar cane leaves by laser induced breakdown spectroscopy(LIBS)
• Grantee: Marcelo Braga Bueno Guerra
• Support Opportunities: Scholarships in Brazil - Post-Doctoral