The Use of Liquid Chromatography and Mass Spectrometry to Identify and Quantify Chemical Components in Tea Extracts

A fast, straightforward, efficient, and high throughput reverse-phase high-performance liquid chromatography and electrospray ionization mass spectrometry method has been developed to analyze tea extracts containing polyphenols. The polyphenols detected in green tea (GT), black tea (BT), and paradise tropical tea (PTT) were separated in 18 min at wavelengths 254 nm, 260 nm, and 280 nm with a gradient elution on the RP-HPLC system. Our approach detected, identified, and quantified three catechins in the tea extracts analyzed, and the response at 280 nm wavelength was the best. The ESI-MS data confirmed the fragmentation patterns of the catechins detected in the tea extract. The validation data showed that the limit of detection (LOD) and limit of quantitation (LOQ) of catechins ranged from 5.26 & PLUSMN; 0.02 to 36.44 & PLUSMN; 0.02 ppb, and 17.52 & PLUSMN; 0.03 to 121.45 & PLUSMN; 0.16 ppb, respectively, for six catechins studied. The standard addition calibration approach used to quantify the catechin content in the tea extract simultaneously showed that PTT has a higher catechin content than GT and BT. The content of polyphenols in GT, BT, and PTT are summarized. This approach holds great promise for quality control studies to quantify polyphenols in nutritional products.