In this study, liquidchromatography–tandemmassspectrometry (LC–MSn; n = 2–3) has been used to characterize and distinguishchlorogenicacidlactones from cinnamoylshikimateesters. This is the first time when an LC–MSn method has been developed to distinguishbetween these two isomeric classes of compounds formed in particular in food processing from chlorogenicacids at elevated temperature through