Determination of Flavonoids in Costus speciosus and Etlingera elatior by Liquid Chromatography-Mass Spectrometry

Abstract

In this article, a new and relatively simple liquid chromatography-mass spectrometry (LC-MS) method was developed for the simultaneous determination of five flavonoid compounds. Under optimized conditions, the LC-MS analysis can be achieved on a reverse-phase C₁₈ column (50 × 2.1 mm, 1.8 µm), with a binary mobile phase consisting of 0.1% formic acid in water and methanol under gradient elution conditions. The relative standard deviations (RSDs) of the retention times and peak areas for all analytes were in the range of 0.1–0.5% and 3.2–5.2%, respectively. The LODs and LOQs were in the range of 2.1–7.0 ng mL⁻¹ and 6.9–23 ng mL⁻¹, respectively. Furthermore, the developed LC-MS method was successfully applied to analyze flavonoids in different parts of two medicinal Zingiberaceae plants (i.e., Costus speciosus and Etlingera elatior) from different sources. The proposed LC-MS method was simple, effective, and reliable, and thus it has potential to be used for the quality control of other medicinal herbs.

Keywords:

• Costus speciosus
• Etlingera elatior
• Flavonoid
• LC-MS
• Zingiberaceae

Acknowledgments

The authors are grateful to Nanyang Technological University (NTU, Singapore) for financial support. Y.Q. Chang acknowledges the award of NTU Postgraduate Research Scholarship.

Notes

^a The data were measured with repeated injections (n = 6) of a mixture of standards at a concentration of 10 µg mL⁻¹.

^b In the calibration equation, x represents concentration of the analyte (mg mL⁻¹) and y represents the peak area (Intens.×s).

^a The data was present as average of duplicates.

^b n.d.: Undetected.

^a The data was present as average of duplicates.

^b n.d.: Undetected.