Evaluation of univariate and multivariate calibration strategies for the direct determination of total carbon in soils by laser-induced breakdown spectroscopy: tutorial

Author(s)

Guedes, Wesley Nascimento ; Babos, Diego Victor ; Costa, Vincius Camara ; De Morais, Carla Pereira ; Freitas, Vitor Da Silveira ; Stenio, Kleydson ; Xavier, Alfredo Augusto Pereira ; Borduchi, Luis Carlos Leva ; Villas-Boas, Paulino Ribeiro ; Milori, Debora Marcondes Bastos Pereira

• Document type: Journal article
• Source: JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS; v. 40, n. 5, p. 12-pg., 2023-05-01.

Abstract

The correct choice of the calibration strategy method is a step that can ensure the accuracy of carbon determination in soils by laser-induced breakdown spectroscopy. In this paper, we evaluate and discuss the intrinsic character-istics of univariate and multivariate calibration strategies in overcoming soil matrix effects and their influence on the magnitude of calibration and prediction error values. The matrix-matching calibration with previous cor-rection of Al spectral interference in the C I line at 193.03 nm was the best strategy of the 13 univariate models evaluated [root-mean-square error of calibration-(RMSEP) = 0.2 wt.% C]. In the multivariate evaluation of the 22 models obtained, the artificial neural network allowed obtaining a lower value of prediction error for C (RMSEP = 0.1 wt.% C) with very good accuracy (98%) for the set samples of validation. The observation of these results was justified considering the advantages and limitations of each calibration strategy explored.(c) 2023 Optica Publishing Group (AU)

• FAPESP's process: 22/05451-0 - Minimizing matrix effect for quantitative analyses of soil samples using the LIBS technique
• Grantee: Luis Carlos Leva Borduchi
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• FAPESP's process: 13/07276-1 - CEPOF - Optics and Photonic Research Center
• Grantee: Vanderlei Salvador Bagnato
• Support Opportunities: Research Grants - Research, Innovation and Dissemination Centers - RIDC