High-Speed Analysis of Catechins in Green Tea using UHPLC

Download PDF August 25, 2017

Introduction

Catechins are in a polyphenol group contained in green tea that yield a bitter taste. They have various physiological functions and have been reported to inhibit high blood pressure, control blood cholesterol, control blood-sugar level, and provide antioxidative, anti-aging, anti-bacterial and anti-allergic activities. The main constituents of catechins in green tea are epicatechin, epigallocatechin, epicatechin gallate, and epigallocatechin gallate.

In this report, catechins in green tea were measured and analyzed by Ultra High-performance Liquid Chromatography(UHPLC) with Photodiode Array Detection.

Jasco XLC-3000

Experimental

Figure 1 shows the chemical structures of 6 catechins and caffeine.

Results

Figure 2 shows a chromatogram and a contour plot of 6 catechines and caffeine. It shows that the 7 different constituents are completely separated within 4 minutes.

Figure 2. Chromatogram and contour plot of 6 catechines and caffeine. 1: EGC (500 µg/mL), 2: C (100 µg/mL), 3: Caffeine (10 µg/mL), 4: EC (100 µg/mL), 5: EGCG (25 µg/mL), 6: ECG (20 µg/mL), 7: CG (100 µg/mL)

Figure 3 shows a chromatogram and a contour plot of green tea. It shows that the 7 different constituents and impurities were separated properly.

Figure 3. Chromatogram and contour plot of green tea extract. The peak numbers and corresponding compounds are the same as in figure 2.
Sample preparation. The sample was filtered using 0.2 mm membrane filter.

About the Author

Miyuki Kanno