Chemical inspection and elemental analysis of electronic waste using data fusion - Application of complementary spectroanalytical techniques

Author(s)

Andrade, Daniel Fernandes ^{[1, 2]} ; de Almeida, Eduardo ^[3] ; Pereira de Carvalho, Hudson Wallace ^[3] ; Pereira-Filho, Edenir Rodrigues ^[2] ; Amarasiriwardena, Dulasiri ^[1]

Affiliation

^[1] Hampshire Coll, Sch Nat Sci, Amherst, MA 01002 - USA

^[2] Univ Fed Sao Carlos, Dept Chem, Grp Appl Instrumental Anal, Rod Washington Luiz Km 235, BR-13565905 Sao Carlos, SP - Brazil

^[3] Univ Sao Paulo, Ctr Nucl Energy Agr, Lab Nucl Instrumentat, Av Centenario 303, BR-13416000 Piracicaba, SP - Brazil

• Document type: Journal article
• Source: Talanta; v. 225, APR 1 2021.
• Web of Science Citations: 0

Abstract

This study is focused on the development of analytical methods for characterization of printed circuit boards (PCBs) from mobile phones by direct analysis using three complementary spectroanalytical techniques: laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS), laser-induced breakdown spectroscopy (LIBS), and micro X-ray fluorescence spectroscopy (micro-XRF). These techniques were combined with principal component analysis (PCA) to investigate the chemical composition on the surface and depth profiling of PCB samples. The spatial distribution of important base metals (e.g. Al, Au, Ba, Cu, Fe, Mg, Ni, Zn), toxic elements (e.g. Cd, Cr, Pb) as well as the non-metallic fraction (e.g. P, S and Si) from conductive tracks, solder mask and integrated components were detected within the PCB samples. Univariate and multivariate approaches were also performed to obtain calibration models for Cu determination. The results were compared to reference concentrations obtained by inductively coupled plasma-optical emission spectrometry (ICP-OES) after microwave-assisted acid leaching using aqua regia. To this end, two PCB samples (50 x 34 mm(2)) were cut into small parts of 40 subsamples (10 x 8.5 mm(2)) and analyzed by ICP-OES and the Cu concentrations ranged from 13 to 45% m m(-1). Partial least squares (PLS) regression was used to data fusion of analytical information from LIBS and micro-XRF analysis. The proposed calibration methods for LIBS and micro-XRF were tested for the 40 PCB subsamples, in which the best results were obtained combining both data sources though a low-level data fusion. Root mean square error of cross validation (RMSEC) and recoveries were 3.23% m m(-1) and 81-119% using leave-one-out cross validation. (AU)

• FAPESP's process: 16/01513-0 - Laser-Induced Breakdown Spectroscopy (LIBS) application in the analyses of electronic waste (printed circuit boards and polymers), food and difficult preparation liquid samples
• Grantee: Edenir Rodrigues Pereira Filho
• Support Opportunities: Regular Research Grants
• FAPESP's process: 15/05942-0 - Shedding light on the metabolism of nanomaterials absorbed by plants with X-ray and vibrational spectroscopy
• Grantee: Hudson Wallace Pereira de Carvalho
• Support Opportunities: Research Grants - Young Investigators Grants
• FAPESP's process: 16/17304-0 - Proposition of methods for direct analysis of electronic waste samples: determination of precious, strategic and toxic elements in printed circuits boards and LCD screens
• Grantee: Daniel Fernandes de Andrade
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 18/24569-6 - Direct element characterization of mobile phones using data fusion from three complementary spectroanalytical techniques
• Grantee: Daniel Fernandes de Andrade
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate
• FAPESP's process: 19/24223-5 - Calibration in Laser-Induced Breakdown Spectroscopy (LIBS): alternatives, challenges, proposals comparison and proposition of a universal procedure
• Grantee: Edenir Rodrigues Pereira Filho
• Support Opportunities: Regular Research Grants