Development and Validation of HPLC-MS2 Methodology for the Accurate Determination of C4-C8 B-type Flavanols and Procyanidins
Abstract Cocoa flavanols and procyanidins (CFs),natural dietary bioactives, have been extensively studied over the past two decades. Human research on the safety and efficacy of CFs is critically dependent upon on the ability to reliably characeterize the research materials that are utilized, and with growing consumer availability of CF-based products, reliable methods for the detection of potential adulteration are of increasing importance. The characterization of CF usually relies on the separation of the analytes by degree of polymerization followed by fluorescence detection, an approach that has recently been validated and accredited as an AOAC Official Method of Analysis (2020.05). More selective methods exploring mass spectrometry detection have been reported, but could not discuss method accuracy due to limited availability of analytical standards. This research focused on the development of a liquid chromatography-tandem mass spectrometry method (HPLC-MS2) using primary standards and synthetic 13C-labelled procyanidins as internal standards. The ability of MS2 detection to discriminate A- and B-type procyanidins was demonstrated. Method performances were validated for degrees of polymerization up to four in seven food model matrices. Accuracy ranged from 90.9 to 125.4 % and precision was <10 % at lower concentration. Finally, the method was applied to cocoa-based samples and compared to AOAC 2020.05, supporting the use of NIST 8403 as reference material for LC-MS analysis.