Principal Component Spectrum Analysis of Licorice Based on Terahertz Radiation
-
摘要: 采用透射式太赫兹时域光谱系统测试了甘草主成分甘草酸、甘草次酸以及甘草苷的太赫兹光谱，发现甘草酸、甘草次酸以及甘草苷在0.3~1.72 THz频段内具有明显的吸收特征，此频段内它们的太赫兹吸收峰峰位接近、吸收谱谱线相似。利用量子化学方法模拟甘草酸的太赫兹吸收谱，并与实验谱进行对比指认完成对3种单质的定性分析工作。本文分别采用基于DFT和PM3模型，完成对甘草酸单分子构型的结构优化与频率计算。结果表明，两种方法得到的太赫兹模拟吸收峰与实验吸收峰基本吻合，而且基于DFT模型得到的太赫兹模拟吸收谱波形与实验谱更为接近。最后选取了甘草酸的特征吸收峰1.655 THz及其附近6个数值点的太赫兹吸收系数，将其取平均值后与浓度进行了一元线性回归拟合，拟合结果从理论上验证了甘草酸太赫兹吸收谱符合朗伯比尔定律。Abstract: In this study, a transmission terahertz time-domain spectrum system was used to test the terahertz spectra of glycyrrhizic acid, glycyrrhetic acid, and glycyrrhizin as the main components of glycyrrhiza (licorice). The characteristics of these licorice constituents and their terahertz absorption peaks were found to be close to each other and their absorption spectra were similar. A quantum chemistry method was used to simulate the terahertz absorption spectrum of glycyrrhizic acid; this spectrum was then compared with the experimental spectrum to perform a qualitative analysis of the three elements. In this study, based on the density functional theory (DFT) and PM3 models, a single molecular configuration of glycyrrhizic acid was introduced for structural optimization and frequency calculation. The results showed that the terahertz simulated absorption peaks obtained by the two methods coincided with the experimental absorption peaks, and the terahertz simulated absorption spectrum waveforms obtained based on the DFT model were closer to those of the experimental spectrum. Finally, the characteristic absorption peak of glycyrrhizic acid at 1.655THz and the terahertz absorption coefficients of six nearby numerical points were selected, and the average value was used to perform a one-dimensional linear regression fitting with the concentration. The fitting results verified the licorice theoretically, and the acid terahertz absorption spectrum conformed to Lambert's law.
-
-
![]()
图 3 甘草酸实验光谱与PM3、DFT计算谱对比
Figure 3. Comparison of glycyrrhizic acid experimental spectrum with PM3, DFT calculated spectrum
![]()
图 4 不同浓度的甘草酸太赫兹吸收谱
Figure 4. THz absorption spectrum of glycyrrhizinate with different contents
表 1 样品配比信息
Table 1 Sample Mixing Information
Sample Sample number Powder/mg Pill weight/mg Thickness/mm Sample proportion/% Glycyrrhizic acid (gcs) gcs1 152.7 144.3 1.3 40 gcs2 157.4 152.7 1.4 40 gcs3 162.9 153.2 1.42 40 gcs4 159.6 154.2 1.4 40 gcs5 143.5 122.8 1.1 40 Liquiritin (gcg) gcg1 157.8 152.3 1.3 45 gcg2 159.5 152.8 1.32 45 gcg3 162.6 154.8 1.3 45 gcg4 157.4 149.2 1.28 45 gcg5 134.7 126.6 1.1 45 Glycyrrhetnic acid (gccs) gccs1 155.9 150.6 1.3 45 gccs2 160.0 143.4 1.32 45 gccs3 163.2 157.4 1.4 45 gccs4 160.4 151.8 1.4 45 gccs5 158.9 151.3 1.44 45 
下载: 导出CSV
表 2 三种样品吸收峰位
Table 2 Peak absorption of three samples
THz No. 1 2 3 4 5 6 7 8 9 Glycyrrhizic acid (gcs) 1.131 1.440 1.561 1.610 1.655 1.704 - - - Liquiritin (gcg) 0.349 0.433 1.437 1.518 1.564 1.606 1.662 1.714 - Glycyrrhetnic acid (gccs) 0.342 0.427 1.004 1.131 1.44 1.574 1.613 1.662 1.714
下载: 导出CSV
表 3 不同浓度甘草酸样品的配比信息
Table 3 Proportion information of glycyrrhizic acid samples with different concentrations
Sample number Powder/mg Pill weight/mg Thickness/mm Sample proportion/% Concentration/(mol/L) gcs01 158.4 155.7 1.28 20 0.312 gcs02 161.2 158.7 1.43 30 0.426 gcs03 159.6 154.2 1.4 40 0.574
下载: 导出CSV
表 4 1.655 THz及其附近6个频率点的吸收系数值
Table 4 Absorption coefficient values at 1.655 THz and 6 frequency points around it
Frequency/THz Absorption/(gcs01) Absorption/ (gcs02) Absorption/ (gcs03) 1.646 10.935 19.566 34.327 1.649 11.026 20.573 35.255 1.652 11.074 21.274 36.572 1.655 11.083 21.473 38.239 1.659 11.061 21.276 36.482 1.662 11.017 20.876 34.127 1.665 10.962 20.404 33.539 Average absorption 11.023 20.777 35.506
下载: 导出CSV
表 5 浓度预测值及相对误差
Table 5 Concentration prediction values and relative errors
Sample number gcs01 gcs02 gcs03 Prediction/(mol/L) 0.316 0.420 0.577 Real/(mol/L) 0.312 0.426 0.574 Relative error/% 1.28 1.41 0.52
下载: 导出CSV
-
[1] ZHANG H, LI Z, CHEN T, et al. Quantitative Determination of Auramine O by Terahertz Spectroscopy with 2DCOS-PLSR Model[J]. Spectrochim Acta A Mol Biomol Spectrosc, 2017, 184: 335-341. DOI: 10.1016/j.saa.2017.05.017
[2] 逯美红, 雷海英, 黄振芬, 等. 基于密度泛函理论的盐酸罂粟碱太赫兹振动光谱计算与分析[J]. 原子与分子物理学报, 2019, 36(6): 908-916. DOI: 10.3969/j.issn.1000-0364.2019.06.004 LU Meihong, LEI haiying, HUANG zhenfen, et al. Density functional theoretical calculations and analysis on terahertz vibrational spectra of papaverine hydrochloride[J]. Journal of Atomic and Molecular Physics, 2019, 36(6): 908-916. DOI: 10.3969/j.issn.1000-0364.2019.06.004
[3] 周永军, 刘劲松, 王可嘉, 等. 基于太赫兹谱分析中药材鉴别[J]. 光谱学与光谱分析, 2014, 34(7): 1840-1843. DOI: 10.3964/j.issn.1000-0593(2014)07-1840-04 ZHOU Yongjun, LIU Jinsong, WANG Kejia, et al. Identification of Chinese Herbal Medicines Based on Terahertz Spectroscopy Analysis[J]. Spectroscopy and Spectral Analysis, 2014, 34(7): 1840-1843. DOI: 10.3964/j.issn.1000-0593(2014)07-1840-04
[4] 刘晓庆, 姚嘉丽, 黄凡, 等. 基于太赫兹时域光谱的青霉素类药物检测研究[J]. 光学学报, 2020, 40(6): 0630001. LIU Xiaoqing, YAO Jiali, HUANG Fan, et al. Studuy on Detection of Penicillin Drugs Based on Terahertz Time-Domain Spectroscopy[J]. Acta Optica Sinica, 2020, 40(6): 0630001.
[5] WANG Yongmei, ZHAO Zongshan, QIN Jianyuan, et al. Rapid in situ analysis of l-histidine and α-lactose in dietary supplements by fingerprint peaks using terahertz frequency-domain spectroscopy[J]. Talanta, 2020, 208: 120469. DOI: 10.1016/j.talanta.2019.120469
[6] 刘丽萍, 王煜斐, 杨霏, 等. 基于太赫兹时域光谱技术的天麻素检测[J]. 中药材, 2018, 41(4): 909-911. LIU Liping, WANG Yufei, YANG fei, et al. Detection of Gastrodin Based on the Terahertz Time-domain Spectroscopy[J]. Journal of Chinese Medical Materials, 2018, 41(4): 909-911.
[7] CHEN H S, DU Q H. Potential natural compounds for preventing 2019-nCOV infection[J]. Preprints Org, 2020. Doi: 10.20944/preprints202001.0358.v3.
[8] 申美仑, 刘广欣, 梁业飞, 等. 甘草酸和甘草次酸提取分离方法的研究进展[J]. 食品工业科技, 2019, 40(18): 326-333. SHEN Meilun, LIU Guangxin, LIANG Yefei, et al. Progress on Extraction and Separation of Glycyrrhizic Acid and Glycyrrhetinic Acid[J]. Science and Technology of Food Industry, 2019, 40(18): 326-333.
[9] 丁玲, 李宏益, 张学文. 实测甘草冠层光谱定量估算甘草酸和甘草苷含量[J]. 光谱学与光谱分析, 2014, 34(7): 1933-1937. DOI: 10.3964/j.issn.1000-0593(2014)07-1933-05 DING Ling, LI Hongyi, ZHANG Xuewen. Quantitative Estimation of Glycyrrhizic Acid and Liquirit in Contents Using In- Situ Canopy Spectroscopy[J]. Spectroscopy and Spectral Analysis, 2014, 34(7): 1933-1937. DOI: 10.3964/j.issn.1000-0593(2014)07-1933-05
[10] ZHANG Tianyao. Characterization of Terahertz Absorption and Dielectric Properties of Solids Based on Time Domain Spectroscopy[D]. Beijing: University of Science and Technology Beijing, 2019.
[11] Duvillaret L, Garet F, Coutaz J L. A Reliable Method for Extraction of Material Parameters in Terahertz Time-Domain Spectroscopy[J]. IEEE Journal of Selected Topics in Quantum Electronics, 1996, 2(3): 739-746. DOI: 10.1109/2944.571775
[12] Duvillaret L, Garet F, Coutaz J L. Highly Precise Determination of Optical Constants and Sample Thickness in Terahertz Time-Domain Spectroscopy[J]. Applied Optics, 1999, 38(2): 409-415. DOI: 10.1364/AO.38.000409
-
期刊类型引用(3)
1. 董期林，张卫国，赵创社，王超，袁屹杰，伊兴国，刘万刚，程勇栋. 滚仰式光电吊舱地理导引实现与误差分析. 中国光学(中英文). 2024(03): 630-639 . 
百度学术
2. 董期林，赵创社，王超，袁屹杰，孔鹏，王马强，高健健，刘万刚，周根东，程勇栋，王毅. 滚仰式光电吊舱对地目标的平移运动补偿. 红外技术. 2024(11): 1339-1346 . 本站查看
3. 王琳，周俊，胡雷刚，白委宁. 直升机光电系统网络协同目标瞄准方法. 应用光学. 2022(01): 17-22 . 百度学术
其他类型引用(1)
计量
- 文章访问数: 366
- HTML全文浏览量: 148
- PDF下载量: 30
- 被引次数: 4
