RRS Determination of Resveratrol with K₃［Fe(CN)₆］FeCl₃ Reaction System

In a BR buffer medium of pH 1.8, K3［Fe(CN)6］ is reduced to K4［Fe(CN)6］ by resveratrol (RES), and K4［Fe(CN)6］ in turn reacts with FeCl3 to form prussian blue, of which the intensity of its RRS is increased abruptly. Values of RRS intensity IRRS are measured at the RRS maximum of 314 nm, values of ΔIRRS (found by substracting blank value from values of IRRS) are found to keep linear relationship with mass concentration of RES in the range of 0.05-5.0 mg·L-1. Detection limit (3s/k) found for RES is 15 μg·L-1. The above mentioned method was used for determination of RES in samples of grape leaves and giant knotweed (a traditional Chinese medicine), giving results in consistency with those found by HPLC. Recovery and precision were tested, values of recovery and RSD′s (n=5) found were in the ranges of 96.0%-104% and 1.7%-4.3% respectively. Mechanism of enhancement of RRS of the reaction system was also discussed priliminarily.