Separation of Curcuminoids from Turmeric – Comparison of Polar Embedded and C18 Solid HPLC Core Columns

Importance of the Topic

Turmeric is widely used as a spice, natural colorant and in traditional medicine due to its curcuminoid pigments. Reliable quantification of curcumin and its derivatives is essential for quality control, authenticity testing and research into health effects.

Objectives and Study Overview

This study compares the separation performance of a polar embedded C18 superficially porous column against a conventional solid core C18 column. The aim is to achieve rapid and complete resolution of major and minor curcuminoids under simple isocratic conditions.

Methodology and Instrumentation

• Sample preparation involved extracting ground turmeric root with 70 percent ethanol at 80 °C, followed by centrifugation, filtration and tenfold dilution in methanol
• Instrumentation comprised a Thermo Scientific Dionex UltiMate 3000RS HPLC system with LPG-3400RS pump, WPS-3000RS autosampler, TCC-3100RS column oven, DAD-3000RS diode array detector and Chromeleon 6.8 software
• Columns evaluated were Accucore Polar Premium (2.6 μm, 100 x 3.0 mm) and a competitor solid core C18 (2.7 μm, 100 x 3.0 mm)
• Chromatographic conditions were isocratic with 80 to 20 methanol to 10 mM phosphoric acid, flow rate of 0.8 mL per minute, column temperature at 40 °C, 6 μL injection volume and detection at 428 nm

Main Results and Discussion

The polar embedded C18 column resolved curcumin, desmethoxycurcumin and bisdesmethoxycurcumin in under three minutes with sharp symmetry. The conventional C18 column showed partial resolution and significant peak tailing under comparable conditions. Both methanol and acetonitrile gave adequate results on the polar column but methanol was favored for cost and phosphoric acid provided satisfactory peak shape with compatibility options for LC MS interfaces. The findings highlight the influence of stationary phase selectivity on separating related natural products.

Benefits and Practical Applications

• Rapid isocratic analysis reduces run time and solvent consumption
• Improved peak symmetry and resolution enhance quantitation accuracy
• Alternate selectivity increases confidence in assay completeness
• Suitable for routine quality control in food, nutraceutical and pharmaceutical laboratories

Future Trends and Opportunities

Alternate polar embedded phases and core shell technologies are poised to expand applications in natural product profiling. Integration with mass spectrometry and further optimization of mobile phases can support broader compound classes. Advancements in superficially porous materials may lead to even higher throughput and selectivity for complex mixtures.

Conclusion

The Accucore Polar Premium column offers superior selectivity for fast, isocratic separation of turmeric curcuminoids compared to a standard solid core C18 column. This technology provides efficient, robust analysis for quality control and research applications.

References

• [1] Wikipedia contributors. Turmeric. Retrieved April 2, 2013
• [2] About com Home Cooking. Turmeric Frequently Asked Questions. Retrieved April 2, 2013
• [3] Wikipedia contributors. Curcumin. Retrieved April 2, 2013