Method performance and multi-laboratory assessment of a normal phase high pressure liquid chromatography-fluorescence detection method for the quantitation of flavanols and procyanidins in cocoa and chocolate containing samples.
Date Published: Friday, June 12, 2009
J Chromatogr A 2009, 1216 (24), 4831-40.
Authors: Robbins, R. J.; Leonczak, J.; Johnson, J. C.; Li, J.; Kwik-Uribe, C.; Prior, R. L.; Gu, L.
The quantitative parameters and method performance for a normal-phase HPLC separation offlavanols and procyanidins in chocolate and cocoa-containing food products were optimized and assessed. Single laboratory method performance was examined over three months using three separate secondary standards. RSD(r) ranged from 1.9%, 4.5% to 9.0% for cocoa powder, liquor andchocolate samples containing 74.39, 15.47 and 1.87 mg/g flavanols and procyanidins, respectively. Accuracy was determined by comparison to the NIST Standard Reference Material 2384. Inter-labassessment indicated that variability was quite low for seven different cocoa-containing samples, with a RSD(R) of less than 10% for the range of samples analyzed.