Feasibility of Rapid Classification of Edible Salts by a Compact Low‐Cost Laser‐induced Breakdown Spectroscopy Device

Abstract

We investigated feasibility of a compact, low-cost, laser-induced breakdown spectroscopy (LIBS) device made up of a Q-switched, diode-pumped, solid-state laser and a nongateable miniature spectrometer for the classification of edible salts. LIBS spectra of edible salts from 12 different geographic origins were obtained by this compact LIBS device. The detection limits of the compact LIBS device for potassium, magnesium, and calcium with effective discrimination power were sufficient to classify the edible salts. The classification model was developed by the multivariate analysis of the LIBS spectra. The comparison of the LIBS results with inductively coupled plasma-atomic emission spectroscopy analysis indicates that the clustering of principal component scores was well dominated by chemical compositions of the salts. The cross-and external validations of the classification model showed reasonable performance (98.3 and 87.5% correctness, respectively). Our results indicate that rapid classification of edible salts can be realized by a compact, low-cost LIBS device.

Soft Independent Modeling of Class Analogy (SIMCA) Modeling of Laser-Induced Plasma Emission Spectra of Edible Salts for Accurate Classification

“…7,9 Our LIBS device composed of the low-power DPSSL and the non-gateable miniature spectrometer provide LODs of 402, 641, and 399 mg/kg for K, Ca, and Mg, respectively. 9 Therefore, the main feature of our LIBS spectra came from K, Mg, Ca, and the matrix elements, Na and Cl. The other minor metallic elements, Li, Sr, Al, Si, Ti, and Fe, that are detectable by using high-performance LIBS spectrometers, could not be detected by the LIBS device used in this work (see the line assignments in Fig.…”

“…Previously, we reported classification of edible salts by PLS-DA modeling based on their LIBS spectra recorded by using a compact low-cost LIBS device consisting of a diode-pumped solid-state laser (DPSSL) and a non-gateable miniature spectrometer. 9 Herein, we report SIMCA analysis of the LIBS spectra obtained by the same simple LIBS device for classification of edible salts. The SIMCA classification model was developed by 144 LIBS spectra of salt samples from 12 different geographical origins.…”

Evaluation of a Thermoelectric Cooler as a Sample Pre-Treatment Method for Laser-Induced Breakdown Spectroscopy (LIBS) Analysis of Liquid Samples

“…The combination of LIBS with PCA has already shown successful results in many areas of knowledge for sample classification. 44–47…”

Laser-Ablation Sampling for Accurate Analysis of Sulfur in Edible Salts

“…Major metallic elements in salt are magnesium (Mg), calcium (Ca), and potassium (K), contained up to a few wt.%. [4][5][6][7] Minor metallic elements are strontium (Sr), lithium (Li), aluminum (Al), silicon (Si), titanium (Ti), and iron (Fe). 4,6,[8][9] Their concentrations are typically less than a few hundred parts-per-million (ppm).…”