Identification of antioxidants in Fructus aurantii and its quality evaluation using a new on-line combination of analytical techniques

► A new analysis method enables on-line identification of antioxidants. ► Ten of the twenty-five flavonoids were new in Fructus aurantii by MSn ► Post-column derivatisation improves identification precision of flavonoids. ► Luminol-K3Fe(CN)6 chemiluminescence is suitable for on-line activity detection. ► O2− scavenging activities of samples show great difference.