Determination of Catechins in Tea by Micellar Electrokinetic Chromatography With a Graphene Oxide-Coated Capillary

Abstract

& A novel approach was developed for the determination of four catechins, (-)-epigallocatechin gallate, (-)-epigallocatechin, (-)-gallocatechin gallate, and (-)-epicatechin, in tea by micellar electrokinetic chromatography (MEKC) using an acidic phosphate buffer (40 mM, 100 mM sodium dodecyl sulfate, and 30% methanol, pH 3.0). The linear dynamic ranges for the catechins were between 25 and 250 lg=mL, and the graphene oxide-coated capillary offered satisfactory accuracy, precision, and limits of detection. The developed method was employed for the determination of catechins in tea.

Simultaneous determination of six catechins and caffeine in tea and wine using salting‐out assisted liquid–liquid extraction and high‐performance liquid chromatography with ultraviolet detection

“…Comparison with previously published methods (Table S2) indicated similar sample limits to Jeon et al [13] and lower limits compared to Zhang et al [14]. Instrumental limits aligned with previous studies [7,9,21,30], indicating the reliability of the instruments used. Despite this, the method employed in this research proves to be sufficiently sensitive for determining catechins in tea samples, as the expected concentrations are higher than the instrumental limits, allowing the use of dilutions when needed.…”

“…Green tea is abundant in the potent antioxidant epigallocatechin gallate (EGCG), along with other catechins like epicatechin gallate (ECG), epigallocatechin (EGC), and epicatechin (EC). These catechins are responsible for tea's health benefits and antioxidant capacity, protecting cells from oxidative damage [6][7][8][9]. Red wine contains antioxidants like resveratrol, which may have heart-protective properties, counteracting some of the adverse effects of alcohol [1][2][3].…”

A dual channel fluorescence tongue for catechin recognition based on the MnO2 nanorods–Amplex Red–o-phenylenediamine reaction system

“…Detection methods for catechins have been reported, including chromatography, 11,12 chemiluminescence and electrochemical methods. [13][14][15][16] Although these methods are accurate and stable, most of them are time-consuming and the preprocessing process is complex, and these chemical sensors are mostly concentrated on single catechin detection.…”