Probing trace lactose from aqueous solutions by terahertz time-domain spectroscopy

Terahertz Spectroscopic Analysis of Lactose in Infant Formula: Implications for Detection and Quantification

“…Figure 1 shows the absorption spectra from measurements under ambient conditions and one of the replicate measurements in a nitrogen atmosphere. The absorption peaks observed are at the frequencies of 0.53, 1.20, 1.37 and 1.82 THz, in agreement with previous studies using THz-TDS [ 20 , 21 , 22 , 23 , 24 , 25 ] and density functional theory simulation [ 24 ]. The absorption peaks obtained from measurements in a nitrogen atmosphere and those obtained under ambient conditions are of the same frequency and magnitude, indicating that the lactose absorption peaks are independent of water absorption.…”

Effect of THz spectra of L-Arginine molecules by the combination of water molecules

“…However, these methods are not used widely because of their relatively poor operability, integration limitations, and high cost. Recently, our team designed a horn-shaped tapered parallel plate waveguide (HSTPPW), which can enhance the electrical field of the incident THz wave at its central position ( Hou et al., 2021 ; Shi et al., 2021 ). Based on HSTPPW, the THz spectral information of substances in an aqueous solution can be obtained by the THz time-domain spectroscopy (THz-TDS) system with high accuracy, although the method is expensive and it is a little difficult to control the thickness of the sample dropped into the waveguide.…”

Study of starch aging characteristics based on Terahertz technology

“…Terahertz spectrum generates terahertz electric field through the interaction between the terahertz pulse and the sample. The waveforms in the time domain and the reference frequency domain are obtained through the fast Fourier transform, and then the waveforms in the frequency domain are processed (Hou et al., 2021 ; Liu & Fan, 2020 ). The absorption coefficient, refractive index, and dielectric constant of the sample can be extracted.…”