High-Speed Analysis of Catechins in Green Tea using UHPLC

By Miyuki Kanno

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.

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.

This document has been prepared based on information available at the time of publication and is subject to revision without notice. Although the contents are checked with the utmost care, we do not guarantee their accuracy or completeness. JASCO Corporation assumes no responsibility or liability for any loss or damage incurred as a result of the use of any information contained in this document. Copyright and other intellectual property rights in this document remain the property of JASCO Corporation. Please do not attempt to copy, modify, redistribute, or sell etc. in whole or in part without prior written permission.