Multi-energy calibration and sample fusion as alternatives for quantitative analysis of high silicon content samples by laser-induced breakdown spectrometry

Abstract

Calibration aiming at quantitative analysis of complex samples is one of the most difficult issues in laser-induced breakdown spectroscopy (LIBS) due to matrix interferences, heterogeneity, and sample particle size effects.

Evaluation of calibration approaches for quantitative analysis of sludge by laser induced breakdown spectrometry

“…The LODs (Table 3) were calculated according to IUPAC recommendations, 45 as previously described for MEC. 31,33…”

“…In order to identify the analyte emission lines in the spectrum, a prior analysis of the sludge was carried out by LIBS with the operational parameters optimized by Carvalho et al 33 The LIBS operational parameters were 0.25 μs delay time, spot size of 65 μm, 267 laser pulses and 20 mJ of laser energy (fluence of 603 J cm −2 ).…”

“…Analytical signals at the selected wavelengths for both test samples were correlated (pellet 2 versus pellet 1) and the analyte amount in the sample was determined from the slope of the resulting calibration curve. 33 For SRC, the pelletized test samples were composed of 0.35 g of CRM029 (or sludge sample) mixed to 0.15 g of cellulose binder. Analyte emission peak areas (I) were plotted as a function of the number of accumulated laser pulses, Np (101, 151, 267, 321, and 405) either in the calibration standard or in the sample.…”

“…The main advantage of this approach is the need for only one standard, but it is important to highlight that its effectiveness depends on the availability of at least three interference-free analytical emission lines. 33…”

Direct determination of Al and Pb in waste printed circuit boards (PCB) by laser-induced breakdown spectroscopy (LIBS): Evaluation of calibration strategies and economic - environmental questions

“…In order to overcome these matrix effects, univariate and multivariate calibration strategies are used for LIBS: matrix-matching calibration (MMC) (Costa et al 2018b, Gomes et al 2013, Vieira et al 2018), standard addition (SA) (Yi et al 2016, one-point gravimetric standard addition (OP GSA) (Babos et al 2019), internal standardization (IS) (Aquino et al 2016, Carvalho et al 2018b, Lasheras et al 2013) calibration free (CF) (Calvacante et al 2013, Ciucci et al 1999, Tognoni et al 2010, one-point and multi-line calibration (OP MLC) (Hao et al 2018), multi-energy calibration (MEC) (Andrade et al 2019b, Babos et al 2018, Carvalho et al 2019, Castro et al 2020, Fortunato et al 2019, twopoint calibration transfer (TP CT) (Castro et al 2020), and single-sample calibration (SSC) (Yan et al 2019).…”