High-performance liquid chromatography/mass spectrometry analysis of proanthocyanidins in foods and beverages

Monomeric and oligomeric proanthocyanidins present in a range of plant-deri ved foods and beverages were separated by degree of polymerization and iden tified using a modified normal-phase highperformance liquid chromatography (HPLC) method coupled with on-line mass spectrometry (MS) analysis using an atmospheric pressure ionization electrospray chamber. In addition, ultravi olet (UV) and fluorescence detection were used to monitor the separation of proanthocyanidins, with fluorescence detection demonstrating both increase d sensitivity and the ability to reduce interfering signals from other comp onents present in the food and beverage matrices as compared to UV detectio n. This qualitative study demonstrates the ability of this HPLC/MS techniqu e to separate singly and doubly linked procyanidins, prodelphinidins, and c opolymer oligomers, including their galloylated derivatives, present in a r ange of food and beverage samples.