Rapid tea catechins and caffeine determination by HPLC using microwave-assisted extraction and silica monolithic column

•Development of a rapid HPLC procedure based on the use of monolithic column.•The use of microwave assisted extraction for the isolation of the catechin compounds.•Application of the methods for the determination of catechins in various types of teas. A rapid reversed-phase high performance liquid chromatographic method using a monolithic column for the determination of eight catechin monomers and caffeine was developed. Using a mobile phase of water:acetonitrile:methanol (83:6:11) at a flow rate of 1.4mLmin−1, the catechins and caffeine were isocratically separated in about 7min. The limits of detection and quantification were in the range of 0.11–0.29 and 0.33–0.87mgL−1, respectively. Satisfactory recoveries were obtained (94.2–105.2±1.8%) for all samples when spiked at three concentrations (5, 40 and 70mgL−1). In combination with microwave-assisted extraction (MAE), the method was applied to the determination of the catechins and caffeine in eleven tea samples (6 green, 3 black and 2 oolong teas). Relatively high levels of caffeine were found in black tea, but higher levels of the catechins, especially epigallocatechin gallate (EGCG) were found in green teas.