Traditional Chinese Medicine meets modern analytics - HPLC fingerprinting for the comparison of Radix Paeonia alba and Radix Paeonia rubra

Significance of the topic

Understanding the chemical fingerprint of Radix Paeonia alba and Radix Paeonia rubra is essential for quality control, correct therapeutic application and regulatory compliance in herbal medicine. Accurate differentiation ensures product authenticity and efficacy in Traditional Chinese Medicine (TCM) preparations.

Objectives and study overview

The primary goal of this study was to develop and validate an HPLC fingerprinting method capable of distinguishing between white and red peony root extracts. A secondary objective was to compare granulate preparations with plant origin samples to establish cultivar-specific profiles.

Methodology and instrumentation

The analysis employed an AZURA HPLC Plus system comprising:

• AZURA AS 6.1L autosampler
• AZURA CT 2.1 column thermostat set at 40 °C
• AZURA P 6.1L LPG pump
• AZURA DAD 2.1L diode array detector with 10 mm, 10 µL PressureProof flow cell

Mobile phase consisted of water with 0.05 % phosphoric acid (A) and acetonitrile (B) under a linear gradient over a 70 min run. Samples were injected as ethanolic extracts (1:10 dilution), detected at 230 nm, and complemented with 3D spectral data (190–700 nm). Separation was achieved on a 250 × 4.6 mm C18 column packed with Eurospher II 100-5 P silica.

Results and discussion

Key findings include:

1. Paeoniflorin identification at 13.40 min in both cultivars.
2. A characteristic peak at 26.00 min exclusive to Radix Paeonia rubra, absent in Radix Paeonia alba.
3. Distinctive triple-peak pattern between 21.3 min and 22.7 min in rubra granulate not observed in plant extracts.

The combination of retention time markers and 3D spectral confirmation enabled reliable differentiation of root variants and formulation types.

Benefits and practical applications

This HPLC fingerprinting approach provides a robust tool for:

• Authentication of herbal raw materials and finished products.
• Quality assurance and batch-to-batch consistency monitoring.
• Regulatory compliance by verifying cultivar-specific composition.

Future trends and applications

Advancements may include integration of chemometric analysis for automated classification, expansion to a wider range of herbal species, and coupling with high-resolution mass spectrometry for comprehensive metabolomic profiling.

Conclusion

The developed HPLC fingerprint method successfully differentiates Radix Paeonia rubra and Radix Paeonia alba, as well as granulate versus plant extracts. It represents an effective quality control strategy to ensure the correct identification and therapeutic reliability of peony root products.

Used instrumentation

• AZURA AS 6.1L autosampler
• AZURA CT 2.1 column thermostat
• AZURA P 6.1L LPG pump
• AZURA DAD 2.1L diode array detector
• Stech Eurospher II 100-5 P C18 column (250 × 4.6 mm)
• ClarityChrom 7.4.2 software with PDA extension

References

• Chunnian H, Yong P, Yuxiong F et al. Quick comparison of Radix Paeonia Alba, Radix Paeonia Rubra, and Cortex Moutan by HPLC and chemical pattern recognition. Pharmacognosy Magazine. 2012;8(31):237–243.
• Chinese Herbs Healing. Red Peonies (Chi Shao Yao) information.
• MyDaoLabs. White Peony Root (Bai Shao) properties and uses.