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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Internal standard fused glass beads for high silicon content sample analysis by laser-induced breakdown spectrometry

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Carvalho, Alexandrina A. C. [1] ; Leme, Flavio O. [2] ; Luz, Maciel S. [3] ; Oliveira, Pedro V. [1] ; Nomura, Cassiana S. [1]
Total Authors: 5
[1] Univ Sao Paulo, Dept Quim Fundamental, Inst Quim, Ave Prof Lineu Prestes 748, BR-05508000 Sao Paulo, SP - Brazil
[2] Univ Fed ABC, Ctr Ciencias Nat & Humanas, Ave Estados 5001, BR-09210971 Santo Andre, SP - Brazil
[3] Inst Pesquisas Tecnol, Ctr Tecnol Met & Mat, Ave Prof Almeida Prado 532, Predio 2, BR-05508901 Sao Paulo, SP - Brazil
Total Affiliations: 3
Document type: Journal article
Source: Journal of Analytical Atomic Spectrometry; v. 33, n. 7, p. 1243-1250, JUL 2018.
Web of Science Citations: 6

The direct analysis of high silicon content samples by Laser-Induced Breakdown Spectrometry (LIBS) is a good alternative, since the decomposition of samples with refractory characteristics is not an easy task. However, poor precision and difficulty in performing quantitative analysis due to particle size effects, heterogeneity and matrix effects are challenges which need to be overcome. An interesting approach to overcome these issues enabling quantitative measurements of Al, Ca, Fe, Mg, Si and Ti in a variety of samples by LIBS is the use of the borate fusion process for sample preparation. Results for fused glass beads were compared to those obtained for samples pressed into pellets, which is the most common sample preparation procedure for analysis by LIBS. The linearity of calibration curves (R-2) using different certified reference materials (CRM) pressed into pellets was worse (R-2 = 0.2105-0.9276) than that observed for those fused into glass beads (R-2 = 0.5640-0.9778), but this still shows a lack of linearity. To minimize strong absorption effects caused by the matrix composition and improve the linearity, accuracy and precision of results for fused glass beads, B and Li, present in the flux, were used as internal standards. Better results were achieved for Fe, Mg and Si when the B emission line was used as an internal standard, while the Li emission line worked better for the measurement of Al, Ca and Ti. The accuracy of the method was evaluated by analyzing a CRM of soil (NIST SRM 2711) and relative errors of around 8% were found, indicating that internal standardization enables quantitative measurement by LIBS in those matrices. (AU)

FAPESP's process: 17/10346-2 - Method development for direct quantitative analysis of high silicon content samples: laser-induced breakdown spectrometry and Total Reflection X-Ray Fluorescence
Grantee:Cassiana Seimi Nomura
Support type: Regular Research Grants
FAPESP's process: 12/11998-0 - Evaluation and production of synthetic calibrating material for direct analysis of wood by LIBS
Grantee:Cassiana Seimi Nomura
Support type: Regular Research Grants