Analysis of Danshen (Salvia Miltrorrhiza) and Compound Danshen Dropping Pills using Poroshell 120 Superficially Porous LC Columns

Importance of the Topic

The authentication and quality assessment of traditional Chinese medicines (TCMs) such as Salvia miltiorrhiza (Danshen) present significant analytical challenges due to their complex natural matrices. Reliable chromatographic fingerprinting is critical to ensure product consistency, detect impurities, and safeguard therapeutic efficacy.

Objectives and Study Overview

This application note investigates the suitability of Agilent Poroshell 120 superficially porous LC columns for the fingerprint analysis of Danshen and Compound Danshen Dropping Pills. The method performance is benchmarked against a Waters HSS T3 UPLC column to assess resolution, peak shape, analysis time, and operating pressure.

Methodology

Sample Preparation:

• Danshen Dropping Pills: 10 pills dissolved in 10 mL water, filtered through 0.45 µm regenerated cellulose.
• Danshen root powder: 2 g extracted with water at 80 °C for 1 hour, volume adjusted to 50 mL, filtered.

Chromatographic Conditions:

• Mobile phase A: 0.02 % H₃PO₄ in water; B: 0.02 % H₃PO₄ in acetonitrile/water (80/20).
• Gradient elution over 10 min for pills and up to 28 min for water extract.
• Column temperature 30–40 °C, detection at 280 nm.
• Injection volumes: 2–4 µL depending on column ID.

Instrumentation

Agilent 1200 Series RRLC system comprising binary pump, autosampler, column compartment, diode array detector. Columns evaluated:

• Agilent Poroshell 120 EC-C18 (3.0×100 mm, 2.7 µm)
• Agilent Poroshell 120 SB-C18 (4.6×100 mm, 2.7 µm)
• Waters HSS T3 UPLC (2.1×100 mm, 1.8 µm)

Main Results and Discussion

Both Poroshell columns achieved baseline separation of eight target analytes in the dropping pills. The EC-C18 phase showed enhanced selectivity, resolving a minor impurity adjacent to peak 6, which SB-C18 did not. Compared to the Waters HSS T3 column, Poroshell EC-C18 delivered equally high resolution with sharper peaks, 20 % shorter run time, and operated at just 57 % of the UPLC back pressure (<287 bar vs. 503 bar). Varying flow rates up to 3 mL/min maintained resolution under 400 bar, demonstrating robust high-throughput capability. Analysis of water extracts confirmed that superficially porous particles afford faster mass transfer and slightly improved resolution over sub-2 µm totally porous phases.

Benefits and Practical Applications

The Poroshell 120 columns combine sub-2 µm efficiency with significantly reduced back pressure, enabling rapid fingerprinting workflows on conventional HPLC systems. This approach enhances laboratory throughput, lowers hardware barriers, and supports comprehensive quality control of Danshen-based formulations.

Future Trends and Opportunities

Expanding superficially porous column technology to other complex herbal medicines can streamline TCM fingerprinting. Integration with mass spectrometry, two-dimensional separations, and fully automated platforms promises greater sensitivity, deeper compositional insights, and greener solvent usage.

Conclusion

Agilent Poroshell 120 superficially porous columns offer a powerful tool for the HPLC fingerprinting of Danshen and its compound preparations. Their high efficiency, low back pressure, and compatibility with standard LC hardware deliver fast, reproducible analyses essential for rigorous TCM quality control.

References

• 1. National Library of Medicine. MedlinePlus Natural Products: Danshen. URL accessed April 2010.
• 2. Chinese Pharmacopoeia Commission. Compound Danshen Dropping Pills. Pharmacopoeia of the People’s Republic of China 2010; 906.