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. 2016 Jun 9:6:27574.
doi: 10.1038/srep27574.

Laser-Induced Breakdown Spectroscopy Coupled with Multivariate Chemometrics for Variety Discrimination of Soil

Ke-Qiang Yu  1   2 , Yan-Ru Zhao  1 , Fei Liu  1   3 , Yong He  1   3
Affiliations

Laser-Induced Breakdown Spectroscopy Coupled with Multivariate Chemometrics for Variety Discrimination of Soil

Ke-Qiang Yu et al. Sci Rep. .

Abstract

The aim of this work was to analyze the variety of soil by laser-induced breakdown spectroscopy (LIBS) coupled with chemometrics methods. 6 certified reference materials (CRMs) of soil samples were selected and their LIBS spectra were captured. Characteristic emission lines of main elements were identified based on the LIBS curves and corresponding contents. From the identified emission lines, LIBS spectra in 7 lines with high signal-to-noise ratio (SNR) were chosen for further analysis. Principal component analysis (PCA) was carried out using the LIBS spectra at 7 selected lines and an obvious cluster of 6 soils was observed. Soft independent modeling of class analogy (SIMCA) and least-squares support vector machine (LS-SVM) were introduced to establish discriminant models for classifying the 6 types of soils, and they offered the correct discrimination rates of 90% and 100%, respectively. Receiver operating characteristic (ROC) curve was used to evaluate the performance of models and the results demonstrated that the LS-SVM model was promising. Lastly, 8 types of soils from different places were gathered to conduct the same experiments for verifying the selected 7 emission lines and LS-SVM model. The research revealed that LIBS technology coupled with chemometrics could conduct the variety discrimination of soil.

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Figures

Figure 1
Figure 1. Representative LIBS spectra curves of six types of soil samples in 300–850 nm.
Figure 2
Figure 2
The ownership of main emission lines in LIBS spectrum of soil sample numbered GBW07447 in (a) 300–400 nm, (b) 400–600 nm, and (c) 600–850 nm (I: atomic spectral lines and II: ionic spectral lines).
Figure 3
Figure 3. The loading plot of first seven PCs from PCA on full spectra of six soil samples.
Figure 4
Figure 4
The score (a) and loading (b) plots of first two PCs from PCA on LIBS spectra at the selected emission lines of six soil samples.
Figure 5
Figure 5. Bar plot of SIMCA model for the predication set of 60 predicated LIBS spectra.
Predicted class IDs were as follows: 1, GBW07410; 2, GBW0746; 3, GBW07447; 4, GBW07454; 5, GBW07455; and 6, GBW07456.
Figure 6
Figure 6. The score plot of first three PCs from PCA on LIBS data of eight types of soil samples in different places.
Figure 7
Figure 7. A representative LIBS analytical system setup for soil analysis.
See this image and copyright information in PMC

References

    1. Martin M. Z., Mayes M. A., Heal K. R., Brice D. J. & Wullschleger S. D. Investigation of laser-induced breakdown spectroscopy and multivariate analysis for differentiating inorganic and organic C in a variety of soils. Spectrochim. Acta B 87, 100–107 (2013).
    1. Miziolek A. W., Palleschi V. & Schechter I. Laser-induced breakdown spectroscopy-fundamentals and applications. Cambridge University Press (2006).
    1. Miretzky P. & Fernandez-Cirelli A. Phosphates for Pb immobilization in soils: a review. Environ. Chem. Lett. 6, 121–133 (2008).
    1. Raven K. P., Reynolds J. W. & Loeppert R. H. Trace element analyses of fertilizers and soil amendments by axial-view inductively-coupled plasma atomic emission spectrophotometry. Commun. Soil Sci. Plan. 28, 237–257 (1997).
    1. Phillips J. D. & Marion D. A. Soil geomorphic classification, soil taxonomy and effects on soil richness assessments. Geoderma 141, 89–97 (2007).

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