[Terahertz time-domain spectroscopy of L-ascorbic acid].
Bing-Hua Cao1, Guang-Xin Zhang, Di-Bo Hou
1State Key Lab of Industrial Control Technology, Department of Control Science and Engineering, Zhejiang University, Hangzhou 310027, China. caobinghua2004@163.com
Guang Pu Xue Yu Guang Pu Fen Xi = Guang Pu
|October 6, 2009
Summary
L-ascorbic acid exhibits distinct terahertz (THz) vibrational spectra, confirmed by both theoretical calculations and experimental THz-time domain spectroscopy. These findings aid in understanding vitamin C
Area of Science:
- Solid-state physics and spectroscopy
- Computational chemistry and quantum mechanics
- Biophysics and biochemistry
Context:
- Terahertz (THz) spectroscopy offers unique insights into molecular vibrations due to its frequency range.
- L-ascorbic acid (vitamin C) plays crucial roles in biological systems, necessitating accurate characterization.
- Understanding the vibrational properties of L-ascorbic acid is key to its biological function and quantification.
Purpose:
- To theoretically and experimentally determine the vibrational frequencies of L-ascorbic acid in the THz range (0.2–2.4 THz).
- To assign observed vibrational peaks using density functional theory (DFT) calculations and experimental THz-time domain spectroscopy (THz-TDS).
- To compare THz absorption spectra of pure L-ascorbic acid with vitamin C tablets and explore THz-TDS for quantification.
Summary:
- Density functional theory (DFT) using the B3LYP algorithm simulated L-ascorbic acid's vibrational frequencies.
- THz-TDS provided experimental absorption and refractive index spectra, with peaks assigned using computational results.
- Distinct L-ascorbic acid fingerprint spectra were identified in the THz region, showing good agreement between theoretical and experimental data.
Impact:
- The study reveals that L-ascorbic acid possesses unique spectral fingerprints in the THz region, useful for identification.
- Intramolecular and intermolecular vibrations jointly contribute to the observed THz absorption peaks.
- The research demonstrates the potential of THz-TDS for the accurate quantification of L-ascorbic acid in various matrices, including vitamin C tablets.
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