Rapid chiral purity identification of mandelic acid by Raman spectra in the O–H stretching region

• Published in: Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy Molecular and biomolecular spectroscopy, 2023-12, Vol.303, p.123251, Article 123251
• Main Authors: Wang, Zhiqiang, Duan, Siqi, Zhang, Ruiting, Ma, Lin, Lin, Ke
• Format: Article
• Language: English
• Subjects: Chiral purity identification; Enantiomeric excess; Mandelic Acid; Molecular structure identification; O–H stretching modes; Raman spectrum
• ISSN: 1386-1425
• DOI: 10.1016/j.saa.2023.123251

[Display omitted] •Spontaneous Raman spectroscopy can be used to measure the purity of chiral molecules.•The O–H stretching vibration band can be used to infer enantiomeric excess (ee value).•A rapid method for detecting the ee value of mandelic acid is proposed. Chiral molecules play a very important role in biological systems, and more and more chiral drugs are used in the treatment of diseases. Mandelic acid (MA) is an important chiral starting substance or the key intermediate of some chiral drugs, and the rapid detection of its chiral purity is very important in the synthesis, separation and detection of drugs. In this study, we developed a method for rapid determination of chiral purity of MA by Raman spectroscopy, and measured a series of Raman spectra of different chiral MA. Through the analysis, it is found that the OH stretching vibration peak can be used to identify the components of chiral molecules, and the enantiomeric excess (ee value) obtained is in good agreement with the real value, and the error is about 5%. The experimental detection speed is fast and the efficiency is high. Our work firstly provides a new idea for the purity detection of chiral molecules by the original Raman spectrum.