Rapid and simultaneous determination of antioxidant markers and caffeine in commercial teas and dietary supplements by HPLC-DAD

► An analytical RP-HPLC-DAD method was developed and validated. ► This method was applied for analysis of 25 herbal samples containing TE and GSE. ► The developed method can allow the separation in less than 12 min. ► It provides a good quality control methodology with minimal sample preparation. ► Tea extraction with boiling water might help consumers in tea brand selection.