University of Shanghai for Science and Technology

Chongqing Institute Forfood and Drug Control

Chenjun Shi

Yan Peng

Yiming Zhu

Songlin Zhuang

Yang Liu

Zhijia Liu

Lin Guo

Xu Wu

Keying Liu

Jiayu Zhao

Liping Wang

Qingrou Yang

Xinyu Tang

Yujian Yang

Linggao Zeng

Tianyi Kou

Zhaozhao Sun

Haicheng Xiao

A method for qualitative identification and quantitative determination of caffeine in a drug. In the method, terahertz absorption coefficient spectra of drugs with different concentrations of caffeine are measured, from which the frequency points, amplitudes and peak areas of characteristic peaks of the drugs with different concentrations of caffeine are obtained as characteristic quantities. Concentration gradients are established between the concentrations and the characteristic quantities, respectively. The characteristic quantities are imported to the SVR model to establish a training set and a test set. Finally, the qualitative identification and quantitative analysis of caffeine in unknown drugs are achieved.

Method for qualitative identification and quantitative determination of caffeine in drug

Disclosed is a method for qualitative and quantitative determination of key substances in mixture based on terahertz spectrum. Terahertz spectrum of a reference mixture is trained through an SVR algorithm, and predicting parameters of key substances in the mixture to be determined after a model is generated. According to the method, an initial pure spectrum corresponding to each composition in the mixture does not need to be separately determined, no limitation on the number of samples contained in the mixture, and no limitation on frequency range to be determined, and the proportion requirement of the mixture in the early test stage is not limited, and the SVR model does not need to be re-trained after a database is formed in the later stage, and the result can be obtained immediately after the spectrum of item to be determined is introduced into the algorithm model.

Method for qualitative and quantitative determination of key substances in mixture based on terahertz spectrum

A method for detecting notoginseng using terahertz technology. The notoginseng samples are pulverized in pulverizer. The pulverized samples are mixed with polyethylene powder in the ratio of 1:4 to 1:6. The powder mixture is pressed in a tablet press to obtain notoginseng tablet. Terahertz spectrograph is started. A peak is saved, and a background signal is measured. The time-domain graph of the background without sample is acquired. The time-domain graphs of the notoginseng tablets are acquired. The time-domain graphs are transformed into frequency-domain graphs by Fourier transform. The frequency-domain graphs are converted to obtain absorption spectrum of the notoginseng tablets. The absorption peak position of test tablet is compared with that of standard tablet to determine its authenticity. The concentration of key active substances of the notoginseng test sample is quantitatively analyzed by integrating the area under absorption peak curve of the notoginseng test sample.

Method for detecting notoginseng using terahertz technology

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Shanghai, China

Chenjun Shi