Effects of univariate and multivariate regression on the accuracy of hydrogen quantification with laser-induced breakdown spectroscopy

Hydrogen Variability in the Murray Formation, Gale Crater, Mars

“…This uncertainty in predicting water content is high, but averaging the prediction for multiple (5-10) ChemCam observation points in a typical raster of a single target, assuming the H content is constant, the uncertainty decreases to ±0.8 wt.% H 2 O. This is within the uncertainty in predicting H content with LIBS estimated by Ytsma and Dyar (2018) of ±1.5 wt.% H 2 O.…”

High-Sensitivity Determination of Nutrient Elements in Panax notoginseng by Laser-induced Breakdown Spectroscopy and Chemometric Methods

“…The variables corresponding to these β = 0 were regarded as non-significant variables to be discarded directly. The penalty method took the value when the penalty likelihood function was the smallest as the estimated value of the regression coefficient [27,37]. Five-fold cross-validation was also applied to establish the Lasso calibration model and confirm the best model parameter the boundary value t, which is analogous to LVs for PLS and the number of non-zero β, which is expressed as either t in the optimization equation or the number of steps in the step-wise procedure.…”

Accurate determination of structural H2O in rocks using LIBS coupled with machine learning algorithms extensively exploring the characteristics of the Hα line

“…Most metallic elements and some metalloid elements such as boron and silicon, with a high enough concentration with respect to the limit of detection of the LIBS technique, have been quantified in rocks, minerals and soils. 1,3 Nonmetal elements analyzed in geological materials using LIBS include carbon, 6 nitrogen, 7 oxygen, 8 fluorine, 9 phosphorus, 10 sulfur, 11 chlorine 12 and hydrogen, 13 with a much lower quantitative analysis performance than for metallic and metalloid elements, and often allow only qualitative analysis 1 due to the high excitation energies of these elements and their important chemical reactivity. Such still modest performance for nonmetal element analysis already presents great potential and has induced many development efforts, since comparable techniques which are able to provide fast and in situ elemental analysis, X-ray fluorescence (XRF) for example, are limited by poor detection limits for light elements and are in particular not suitable for analysis of hydrogen.…”