Quantitative online sheath-flow surface enhanced Raman spectroscopy detection for liquid chromatography

Area of Science:

• Analytical Chemistry
• Spectroscopy
• Chromatography

Background:

• Online detection and quantification of small molecules are crucial in various scientific fields.
• Surface-enhanced Raman spectroscopy (SERS) offers high sensitivity for molecular detection.
• Integrating SERS with separation techniques like liquid chromatography (LC) enhances analytical capabilities.

Purpose of the Study:

• To develop and validate a sheath-flow SERS method for online detection and quantification of small molecules.
• To assess the performance of SERS coupled with UV-Vis detection for characterizing separated metabolites.
• To establish a reliable quantitative detection method using an internal standard.

Main Methods:

• Utilized sheath-flow surface-enhanced Raman spectroscopy (SERS) for real-time analysis.
• Employed liquid chromatography (LC) for the separation of a model mixture of metabolites (thiamine, folic acid, riboflavin).
• Connected UV-Vis and SERS detectors in series for comprehensive characterization.
• Incorporated acetonitrile in the mobile phase as an internal standard for quantification.

Main Results:

• Successfully demonstrated online detection and quantification of model metabolites using sheath-flow SERS.
• UV-Vis and SERS detectors provided complementary information for metabolite characterization.
• Acetonitrile as an internal standard enabled accurate and reproducible quantitative SERS measurements.

Conclusions:

• Sheath-flow SERS is a powerful technique for online quantification of small molecules separated by LC.
• The developed method offers a sensitive and reliable approach for metabolite analysis.
• The use of an internal standard enhances the robustness of quantitative SERS detection.