High-Sensitivity Determination of Nutrient Elements in Panax notoginseng by Laser-induced Breakdown Spectroscopy and Chemometric Methods
Abstract
:1. Introduction
2. Materials and Methods
2.1. Panax notoginseng Samples
2.2. Spectral Acquisition
2.3. Reference Method for Nutrient Elements’ Content Determination
2.4. Data Analysis
2.4.1. Data Preprocessing
2.4.2. Multivariate Analysis Methods
2.4.3. Performance Evaluation
2.4.4. Software Tools
3. Results
3.1. Nutritive Elements Content of Panax Notoginseng
3.2. LIBS Spectra Analysis
3.3. Univariate Analysis
3.4. Multivariate Analysis
3.4.1. Modeling Using Full Spectra
3.4.2. Modeling Using Selected Variables
4. Discussion
5. Conclusions
Author Contributions
Funding
Acknowledgments
Conflicts of Interest
References
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Sample Availability: Samples of the Panax notoginseng are not available from the authors. |
Element | Groups a | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 |
---|---|---|---|---|---|---|---|---|---|
Number | 13 | 13 | 13 | 13 | 13 | 13 | 13 | 13 | |
K | Min | 11.5682 | 8.2990 | 12.1523 | 11.0964 | 7.8709 | 6.4402 | 10.2981 | 8.7456 |
Max | 17.4899 | 15.4417 | 19.7162 | 18.3589 | 10.8974 | 13.8608 | 15.8312 | 18.0112 | |
Mean | 14.0558 | 11.7255 | 16.0186 | 14.7329 | 9.3546 | 10.0683 | 12.8228 | 13.9661 | |
S.D. | 1.6676 | 1.9894 | 2.5840 | 2.0317 | 0.9795 | 1.8793 | 1.4315 | 2.71071 | |
Ca | Min | 1.4194 | 1.1814 | 1.5225 | 1.2717 | 1.2216 | 1.0807 | 1.0997 | 1.4007 |
Max | 2.1659 | 1.8081 | 2.4316 | 2.3112 | 1.8509 | 2.3226 | 1.9342 | 2.3260 | |
Mean | 1.7756 | 1.4200 | 1.9667 | 1.6736 | 1.4758 | 1.3450 | 1.4921 | 1.8509 | |
S.D. | 0.2292 | 0.2062 | 0.4276 | 0.3137 | 0.1993 | 0.3683 | 0.2203 | 0.4987 | |
Mg | Min | 0.8821 | 0.8153 | 1.0908 | 1.1779 | 1.0813 | 0.5774 | 0.9143 | 1.1373 |
Max | 1.2918 | 1.4632 | 1.9072 | 1.6739 | 1.7435 | 1.1640 | 1.8240 | 1.8797 | |
Mean | 1.1343 | 1.0583 | 1.5977 | 1.4081 | 1.3567 | 0.7984 | 1.2961 | 1.3825 | |
S.D. | 0.1194 | 0.1824 | 0.2170 | 0.1559 | 0.2113 | 0.1802 | 0.2730 | 0.2240 | |
Fe | Min | 0.0288 | 0.0711 | 0.0837 | 0.1003 | 0.0661 | 0.0781 | 0.1154 | 0.0783 |
Max | 0.8145 | 0.3023 | 1.0317 | 0.9004 | 0.3862 | 0.5021 | 0.7329 | 0.7258 | |
Mean | 0.2401 | 0.1598 | 0.5550 | 0.4918 | 0.1885 | 0.1903 | 0.3003 | 0.3785 | |
S.D. | 0.0938 | 0.0668 | 0.1039 | 0.0546 | 0.0869 | 0.0779 | 0.0803 | 0.0840 | |
Zn | Min | 0.0147 | 0.0075 | 0.0122 | 0.0116 | 0.0103 | 0.0085 | 0.0069 | 0.0121 |
Max | 0.0351 | 0.0225 | 0.0303 | 0.0250 | 0.0159 | 0.0217 | 0.0159 | 0.0242 | |
Mean | 0.0203 | 0.0130 | 0.0213 | 0.0192 | 0.0129 | 0.0131 | 0.0113 | 0.0183 | |
S.D. | 0.0073 | 0.0037 | 0.0089 | 0.0044 | 0.0016 | 0.0041 | 0.0022 | 0.0041 | |
B | Min | 0.0091 | 0.0061 | 0.0057 | 0.0035 | 0.0038 | 0.0027 | 0.0074 | 0.0047 |
Max | 0.0154 | 0.0148 | 0.0165 | 0.0159 | 0.0134 | 0.0167 | 0.0147 | 0.0156 | |
Mean | 0.0138 | 0.0105 | 0.0131 | 0.0130 | 0.0074 | 0.0079 | 0.0105 | 0.0132 | |
S.D. | 0.0032 | 0.0024 | 0.0066 | 0.0057 | 0.0026 | 0.0036 | 0.0023 | 0.0038 |
Elements | Wavelength (nm) |
---|---|
C I | 247.86, 296.72 |
Si I | 250.68, 251.43, 251.61, 251.92, 252.41, 288.15 |
Fe I | 302.06, 371.99, 385.99, 293.69, 498.24, 499.41 |
Fe II | 253.54, 257.60, 259.37, 260.54, 263.08, |
Mg I | 277.98, 382.94, 383.23, 383.83, 389.19, 516.73, 517.27, 518.36 |
Mg II | 279.55, 279.80, 280.27 |
Ca I | 299.50, 300.09, 300.69, 422.67, 428.30, 428.94, 429.90, 430.25, 430.77, 431.87, 442.54, 443.50, 458.15, 458.60, 527.03, 558.87, 559.45, 559.85, 585.75, 610.27, 612.22, 616.22, 643.91, 644.98, 646.26, 649.38, 671.77, 714.82, 854.21 |
Ca II | 315.89, 317.93, 373.69, 393.37, 396.85, 866.21 |
Sc II | 364.37 |
CN | 385.01 (CN 4-4), 385.44 (CN 3-3), 386.15 (CN 2-2), 387.12 (CN 1-1), 388.32 (CN 0-0) |
Al I | 394.40, 396.15 |
K I | 693.87, 766.49, 769.90 |
Sr I | 460.73 |
Sr II | 407.77, 421.55 |
Na I | 589.00, 589.59 |
H | 656.28 |
O I | 777.42, 844.67 |
Li I | 670.79 |
N I | 742.36, 744.23, 746.83, 818.48, 821.63, 824.23, 862.92, 868.02 |
Emission Lines nm | Calibration Set | Prediction Set | ||
---|---|---|---|---|
Rc | RMSECV mg/g | Rp | RMSEP mg/g | |
K I 766.49 | 0.8324 | 1.4002 | 0.7476 | 1.7601 |
K I 769.90 | 0.8413 | 1.3707 | 0.7836 | 1.6103 |
Ca II 393.37 | 0.6872 | 0.1284 | 0.6327 | 0.1282 |
Ca II 396.85 | 0.7764 | 0.1104 | 0.7118 | 0.1160 |
Ca I 422.67 | 0.7941 | 0.1062 | 0.7779 | 0.1074 |
Mg I 517.27 | 0.8403 | 0.1519 | 0.7564 | 0.1927 |
Mg I 518.36 | 0.7520 | 0.1840 | 0.7168 | 0.2025 |
Fe I 373.71 | 0.7509 | 0.1217 | 0.8378 | 0.1027 |
Fe I 371.99 | 0.8944 | 0.0820 | 0.8577 | 0.0973 |
Element | Model | Parameter | Calibration Set | Prediction Set | ||
---|---|---|---|---|---|---|
Rc | RMSECV mg/g | Rp | RMSEP mg/g | |||
K | PLS d | 10 a | 0.9558 | 0.8120 | 0.9505 | 0.7152 |
LS-SVM | (992.5, 799,024.9) b | 0.9800 | 0.3120 | 0.9391 | 0.8721 | |
Lasso | 53 c | 0.9547 | 0.7740 | 0.9496 | 0.7956 | |
Ca | PLSd | 13 a | 0.9563 | 0.0868 | 0.9513 | 0.0722 |
LS-SVM | (111.5, 16,929,970) b | 0.9799 | 0.0357 | 0.9135 | 0.1101 | |
Lasso | 54 c | 0.9533 | 0.0872 | 0.9508 | 0.0798 | |
Mg | PLS | 11 a | 0.9270 | 0.1066 | 0.9171 | 0.1182 |
LS-SVM | (236.1, 344,300.9) b | 0.9601 | 0.0986 | 0.9011 | 0.1246 | |
Lassod | 51 c | 0.9294 | 0.1022 | 0.9207 | 0.1110 | |
Fe | PLS | 4 a | 0.9234 | 0.0791 | 0.9334 | 0.0906 |
LS-SVM | (311.9, 4,680,480) b | 0.9799 | 0.0451 | 0.9284 | 0.0854 | |
Lassod | 51 c | 0.9506 | 0.0549 | 0.9348 | 0.0762 | |
Zn | PLSd | 4 a | 0.9503 | 0.0017 | 0.9460 | 0.0016 |
LS-SVM | (289.3, 1,593,133.6) b | 0.9886 | 0.0009 | 0.9060 | 0.0021 | |
Lasso | 54 c | 0.9406 | 0.0015 | 0.9228 | 0.0019 | |
B | PLSd | 4 a | 0.9566 | 0.0008 | 0.9475 | 0.0010 |
LS-SVM | (244.1, 48,672.5) b | 0.9866 | 0.0007 | 0.9036 | 0.0014 | |
Lasso | 52 c | 0.9502 | 0.0009 | 0.9348 | 0.0009 |
Element (number) | Model | Parameter | Calibration Set | Prediction Set | ||
---|---|---|---|---|---|---|
Rc | RMSECV mg/g | Rp | RMSEP mg/g | |||
K (64) | PLS | 8 a | 0.9655 | 0.6852 | 0.9530 | 0.7853 |
LS-SVM d | (192.1, 6,274.1) b | 0.9894 | 0.3864 | 0.9546 | 0.7704 | |
Lasso | 78 c | 0.9689 | 0.6491 | 0.9482 | 0.8239 | |
Ca (73) | PLS | 13 a | 0.9420 | 0.0638 | 0.9047 | 0.0757 |
LS-SVM d | (691.7, 19,536.2) b | 0.9890 | 0.0299 | 0.9176 | 0.0712 | |
Lasso | 66 c | 0.9416 | 0.0639 | 0.9012 | 0.0776 | |
Mg (61) | PLS | 7 a | 0.9405 | 0.0957 | 0.9365 | 0.0979 |
LS-SVM d | (146.2, 3,195.7) b | 0.9833 | 0.0053 | 0.9412 | 0.1000 | |
Lasso | 60 c | 0.9236 | 0.1080 | 0.9291 | 0.1034 | |
Fe (66) | PLS d | 6 a | 0.9299 | 0.0684 | 0.9169 | 0.0724 |
LS-SVM | (2585.9, 20,694.3) b | 0.9999 | 0.0002 | 0.9159 | 0.0891 | |
Lasso | 100 c | 0.9070 | 0.0784 | 0.9034 | 0.0801 | |
Zn (73) | PLS | 6 a | 0.9158 | 0.0018 | 0.9613 | 0.0012 |
LS-SVM d | (81.3, 3,389.1) b | 0.9838 | 0.0009 | 0.9665 | 0.0012 | |
Lasso | 100 c | 0.9561 | 0.0013 | 0.9100 | 0.0019 | |
B (62) | PLS | 6 a | 0.9579 | 0.0008 | 0.9432 | 0.0009 |
LS-SVM d | (569.8, 16,582.3) b | 0.9857 | 0.0005 | 0.9569 | 0.0008 | |
Lasso | 70 c | 0.9515 | 0.0009 | 0.9195 | 0.0011 |
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Shen, T.; Li, W.; Zhang, X.; Kong, W.; Liu, F.; Wang, W.; Peng, J. High-Sensitivity Determination of Nutrient Elements in Panax notoginseng by Laser-induced Breakdown Spectroscopy and Chemometric Methods. Molecules 2019, 24, 1525. https://doi.org/10.3390/molecules24081525
Shen T, Li W, Zhang X, Kong W, Liu F, Wang W, Peng J. High-Sensitivity Determination of Nutrient Elements in Panax notoginseng by Laser-induced Breakdown Spectroscopy and Chemometric Methods. Molecules. 2019; 24(8):1525. https://doi.org/10.3390/molecules24081525
Chicago/Turabian StyleShen, Tingting, Weijiao Li, Xi Zhang, Wenwen Kong, Fei Liu, Wei Wang, and Jiyu Peng. 2019. "High-Sensitivity Determination of Nutrient Elements in Panax notoginseng by Laser-induced Breakdown Spectroscopy and Chemometric Methods" Molecules 24, no. 8: 1525. https://doi.org/10.3390/molecules24081525