Selection of Spectral Variables in Multivariate Calibration of C, Mn, Si, Cr, Ni, and Cu Concentrations in Low-Alloy Steels by Laser-Induced Breakdown Spectroscopy

Atomic spectrometry update: review of advances in the analysis of metals, chemicals and materials

“…Two papers by Belkov et al discussed the use of partial least squares regression analysis combined with LIBS for the analysis of low alloy steels 13 and both low alloy steels and cast irons. 14 The papers had a slightly different focus, with one comparing three different methods of selecting the spectral variables 13 and the other comparing the efficiency of various methods of spectrum processing. 14 In the latter case, normalisation to the baseline, localisation of the spectral range and the addition of non-linear components of the spectrum allowed the accuracy of the regression model to be improved.…”

“…This value also resulted in maxima for the electron temperature, electron density and ablation mass. Wust et al employed Laser Ablation Molecular Isotopic Spectroscopy (LAMIS) to characterise C isotopes on graphite using 13 C isotopically-marked methane. 163 The carbon deposition pattern was studied ex situ using LAMIS on Plasma Facing Components on two graphite Test Divertor Units, with clear distinction between 12 C and 13 C. Ultra-short collinear double pulse congurations were used, the rst to generate a laser-induced plasma and the second to direct the sample into the plasma.…”

“…It is hoped that instrument manufacturers are aware of this and are updating their soware as data processing theory develops due to ongoing research by groups such as that of Laborda, and as SP-ICP-MS matures. The authors of the review also considered the future perspectives for SP-ICP-MS, highlighting the recent move towards detecting plastic particles, directly through 12 C and 13 C or via polyatomic species, where the LOD size increases to 1 mm or greater due to the relatively high C background. They also discussed developments in sample introduction systems, and how those for SP and single cell analyses are converging for larger particle sizes, and the recent development of different instrument congurations for SP and single cell work.…”

“…However, the author emphasises that most workers use assessment of comparison intervals and likelihood ratios. An inter-laboratory comparison, conducted as part of an IAEA study, for the forensic analysis of glasses was reported by Kaspi et al 289 Samples (48) were collected by the Israeli police from cars of different model (13) and manufacturer (10) and distributed to laboratories in Israel, Croatia and Finland. Ion beam methods of analysis, particularly PIXE, was used by the laboratories.…”

“…Two papers by Belkov et al discussed the use of partial least squares regression analysis combined with LIBS for the analysis of low alloy steels 13 and both low alloy steels and cast irons. 14 The papers had a slightly different focus, with one comparing three different methods of selecting the spectral variables 13 and the other comparing the efficiency of various methods of spectrum processing.…”