Application of one-point calibration LIBS for quantification of analytes in samples with distinct matrix characteristics: a case study with Hg

Author(s)

Leva Borduchi, Luis Carlos ; Menegatti, Carlos Renato ; Milori, Debora Marcondes Bastos Pereira ; Izario Filho, Helcio Jose ; Villas-Boas, Paulino Ribeiro

• Document type: Journal article
• Source: Journal of Analytical Atomic Spectrometry; v. 38, n. 5, p. 9-pg., 2023-03-17.

Abstract

Laser-induced breakdown spectroscopy (LIBS) is a powerful analytical technique for elemental analysis, but matrix effects can significantly affect its accuracy. In this work, we propose the use of calibration-free LIBS (CF-LIBS) with the one-point calibration (OPC) method to reduce matrix effects in the quantification of mercury (Hg) for seven soil and eleven landfill leachate samples, with Hg concentration ranging from 50 to 1000 mg kg(-1). To improve sensitivity, we employed a double-pulse LIBS system with parameters optimized for each of the two sample matrices. A single soil sample was used to calibrate the OPC factors, which were then applied to the CF-LIBS calculations for the other samples. Using CF-LIBS corrected with the OPC method, we achieved an average error of 4.3% in the quantification of Hg for the two sample sets. This result indicates that these methods have the potential not only to reduce matrix effects but also to compensate for variations in LIBS system optimization for either matrix (soils and leachates) in the quantification of Hg. Therefore, the combination of these methods opens new possibilities for LIBS analyses, where the system can be optimized for each element and sample matrix, and the quantification can be performed with CF-LIBS, as long as the requirements for local thermodynamic equilibrium are fulfilled. Further studies with other elements, matrices, and measurement conditions are needed to validate and expand these findings. (AU)

• FAPESP's process: 17/19248-3 - Using the LIBS technique for the study of heavy metals in leachate liquid samples
• Grantee: Carlos Renato Menegatti
• Support Opportunities: Regular Research Grants
• 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