Abstract: 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.

Abstract: 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.

Abstract: A method for quantitative detection of blood lipid in blood based on terahertz spectroscopy, including: matching the terahertz spectral absorption coefficient curves of blood samples obtained in step 3 with parameters of component concentration and component type of the blood lipid detected by hospital instruments, and establishing a terahertz blood lipid parameter database by combining the time-domain signal data of samples of the triglyceride and cholesterol; determining parameters of a support vector regression (SVR) model; performing a training with the training set as input to the SVR model to obtain a support vector and a corresponding weight; and testing the test set of an unknown blood sample using the trained support vector and the corresponding weight.

Abstract: A method for quantitative detection of blood lipid in blood based on terahertz spectroscopy, including: matching the terahertz spectral absorption coefficient curves of blood samples obtained in step 3 with parameters of component concentration and component type of the blood lipid detected by hospital instruments, and establishing a terahertz blood lipid parameter database by combining the time-domain signal data of samples of the triglyceride and cholesterol; determining parameters of a support vector regression (SVR) model; performing a training with the training set as input to the SVR model to obtain a support vector and a corresponding weight; and testing the test set of an unknown blood sample using the trained support vector and the corresponding weight.