Matrix-Matching Calibration Using Solid Standards: A Comparison between Univariate and Multivariate Strategies for the Determination of Calcium and Magnesium in Bean Seed Samples Employing Laser-Induced Breakdown Spectroscopy (LIBS)

Abstract

The aim of this study was to evaluate solid calibration standards for matrix-matching comparing with multivariate calibration strategies for calcium and magnesium determination in bean seed samples employing laser-induced breakdown spectroscopy combined with direct solid analysis. Four calibration strategies, namely, (i) partial least square (PLS), (ii) principal component regression (PCR), (iii) multi-energy calibration (MEC) and (iv) one-point gravimetric standard addition (OP GSA), were assessed for fourteen bean seed samples. From all calibration strategies used in this study, univariate calibrations (MEC and OP GSA) led to better results, where for MEC, the trueness values ranged from 89 to 188% for Ca, and from 75 to 116% for Mg, and for OP GSA ranged from 76 to 112% for Ca, and 87 to 127% for Mg. Therefore, the use of solid standard combined with univariate calibration strategies has improved the accuracy by minimizing the matrix effects with appropriate blank and standard dilution.