Please use this identifier to cite or link to this item: http://repositorio.unicamp.br/jspui/handle/REPOSIP/350
Type: Artigo de periódico
Title: Optimization and validation of a LIBS method for the determination of macro and micronutrients in sugar cane leaves
Author: NUNES, Lidiane Cristina
BRAGA, Jez Willian Batista
TREVIZAN, Lilian Cristina
SOUZA, Paulino Florencio de
CARVALHO, Gabriel Gustinelli Arantes de
SANTOS JUNIOR, Dario
POPPI, Ronei Jesus
KRUG, Francisco Jose
Abstract: Laser induced breakdown spectrometry (LIBS) was applied for the determination of macro (P, K, Ca, Mg) and micronutrients (B, Cu, Fe, Mn and Zn) in sugar cane leaves, which is one of the most economically important crops in Brazil. Operational conditions were previously optimized by a neuro-genetic approach, by using a laser Nd:YAG at 1064 nm with 110 mJ per pulse focused on a pellet surface prepared with ground plant samples. Emission intensities were measured after 2.0 mu s delay time, with 4.5 mu s integration time gate and 25 accumulated laser pulses. Measurements of LIBS spectra were based on triplicate and each replicate consisted of an average of ten spectra collected in different sites (craters) of the pellet. Quantitative determinations were carried out by using univariate calibration and chemometric methods, such as PLSR and iPLS. The calibration models were obtained by using 26 laboratory samples and the validation was carried out by using 15 test samples. For comparative purpose, these samples were also microwave-assisted digested and further analyzed by ICP OES. In general, most results obtained by LIBS did not differ significantly from ICP OES data by applying a t-test at 95% confidence level. Both LIBS multivariate and univariate calibration methods produced similar results, except for Fe where better results were achieved by the multivariate approach. Repeatability precision varied from 0.7 to 15% and 1.3 to 20% from measurements obtained by multivariate and univariate calibration, respectively. It is demonstrated that LIBS is a powerful tool for analysis of pellets of plant materials for determination of macro and micronutrients by choosing calibration and validation samples with similar matrix composition.
Country: Inglaterra
Editor: ROYAL SOC CHEMISTRY
Citation: JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY, v.25, n.9, p.1453-1460, 2010
Rights: fechado
Identifier DOI: 10.1039/c003620j
Address: http://apps.isiknowledge.com/InboundService.do?Func=Frame&product=WOS&action=retrieve&SrcApp=EndNote&UT=000281109600012&Init=Yes&SrcAuth=ResearchSoft&mode=FullRecord
http://dx.doi.org/10.1039/c003620j
Date Issue: 2010
Appears in Collections:IQ - Artigos e Materiais de Revistas Científicas

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