Analysis of Syringin in Herbal medicine

Significance of the topic

Quantitative determination of syringin in herbal medicines is essential for quality control and standardization of botanical products. Syringin, a glucoside of sinapyl alcohol, contributes to the therapeutic properties of lilac and other plant extracts. Reliable analytical methods ensure consistent dosage, detect adulteration, and support pharmacological research.

Objectives and Overview

This application note describes an isocratic reversed-phase liquid chromatography method for the analysis of syringin in herbal medicine samples. The goals are to develop a robust sample preparation procedure, achieve good chromatographic separation using Shim-pack VP-ODS column, and demonstrate reliable detection by UV absorption at 265 nm.

Methodology

Sample preparation employs a multi-step extraction and cleanup workflow:

• Grind 2 g of herbal medicine to a fine powder.
• Extract with 50 mL of 50% methanol/water under ultrasonic treatment (250 W, 40 kHz) for 30 minutes.
• Adjust the extract weight to compensate for solvent loss, shake, and filter.
• Evaporate 10 mL of filtrate to dryness; dissolve residue in 5 mL of 50% methanol.
• Perform cleanup on a neutral alumina column (4 g, 100–200 mesh) eluting with 90 mL of 50% methanol.
• Evaporate the eluate and reconstitute to 2 mL with 50% methanol for analysis.

Instrumentation Used

The chromatographic system is configured as follows:

• Column: Shim-pack VP-ODS, 250 mm × 4.6 mm I.D., 5 μm.
• Mobile phase: isocratic mixture of water (component A) and methanol (component B) at a ratio of 82 A : 18 B.
• Flow rate: 1.0 mL/min.
• Column temperature: 30 °C.
• Injection volume: 10 μL.
• Detection: UV absorbance at 265 nm.

Main Results and Discussion

Chromatograms of both the syringin standard and the herbal extract demonstrate a single sharp peak at the expected retention time, indicating good resolution from sample matrix components. The method yields reproducible peak areas and retention times, confirming its suitability for routine quality control. No significant interfering peaks were observed under the selected conditions.

Benefits and Practical Applications

This protocol offers:

• Simple sample preparation combining ultrasound extraction and alumina column cleanup.
• Isocratic operation for ease of use and minimal solvent consumption.
• Reliable UV detection without the need for more complex detectors.
• Applicability to routine analysis in pharmaceutical or nutraceutical laboratories for batch release and stability studies.

Future Trends and Potential Applications

Advances may include coupling this method with mass spectrometry for enhanced specificity, miniaturization of sample preparation to reduce solvent use, and adoption of automated online cleanup systems. Green chromatography approaches could optimize solvent selection, and high-throughput platforms may accelerate screening of large sample sets.

Conclusion

The described reversed-phase LC method with UV detection provides a robust and reproducible approach for quantifying syringin in herbal medicines. Its straightforward workflow and consistent performance make it well suited for routine quality assurance and research applications.