Analysis of notoginseng using C18 chemistries on superficially porous particle columns

Significance of the Topic

Notoginseng is widely used herbal medicine with bioactive saponins that require reliable quantitation in quality control and research. Efficient UHPLC methods enable faster analysis, reduced solvent consumption, and improved laboratory throughput, supporting pharmaceutical and natural product industries.

Objectives and Study Overview

This study aimed to adapt the China Pharmacopoeia method for total saponins analysis of notoginseng to modern superficially porous particle columns and to compare three C18 chemistries. The goals included reducing run time and solvent use while maintaining or improving resolution of key ginsenosides R1, Rg1, Re, Rb1, and Rd.

Methodology

• Sample preparation by dissolving notoginseng total saponins in methanol
• UHPLC separation on superficially porous C18 columns of dimensions 4.6 × 250 mm 4 µm and 3.0 × 100 mm 2.7 µm
• Gradient elution using water and acetonitrile at 203 nm detection
• Gradient optimization to maintain separation while shortening analysis time

Used Instrumentation

• Agilent 1290 Infinity II high speed pump, multisampler, MCT, DAD
• Agilent InfinityLab fittings and Econofilter PTFE membrane filters
• ELGA PURELAB water purification system
• Agilent OpenLab CDS software

Main Results and Discussion

The InfinityLab Poroshell HPH-C18 column with a 3.0 × 100 mm 2.7 µm format delivered comparable resolution to the original 4.6 × 250 mm 4 µm column while reducing analysis time by 70 percent and solvent use by over 80 percent. Among the tested phases, HPH-C18 provided superior selectivity for minor saponin peaks that coeluted on EC-C18 and SB-C18 columns. Resolution between ginsenosides Rg1 and Re remained consistent with Rs around 2.3.

Benefits and Practical Applications

This optimized method supports high throughput analysis in quality control laboratories, lowering operational costs and environmental impact. The approach is directly transferable to compliance testing according to pharmacopeial standards and adaptable to other herbal saponin analyses.

Future Trends and Applications

Advances in superficially porous particle technology and UHPLC instrumentation will drive further reductions in runtime and solvent consumption. Future work may explore coupling with mass spectrometry, automated sample preparation, and expansion to diverse botanical matrices to meet evolving analytical demands.

Conclusion

Transferring the pharmacopeial notoginseng saponin assay to a 3.0 × 100 mm HPH-C18 superficially porous column provides a rapid, solvent efficient, and robust method. The HPH-C18 phase offers unique selectivity and supports modern analytical workflows in pharmaceutical and natural product laboratories.

Reference

1. Total Notoginseng Saponins, China Pharmacopoeia 2015 514