氯化铁-铁氰化钾体系共振瑞利散射法测定白藜芦醇

RRS Determination of Resveratrol with K_3[Fe(CN)_6]-FeCl_3 Reaction System

在pH 1.8的B-R缓冲溶液中,白藜芦醇(RES)使[Fe(CN)6]3-还原为[Fe(CN)6]4-,后者与铁(Ⅲ)反应生成普鲁士蓝,其共振瑞利散射(RRS)急剧增强。于最大RRS峰314nm处测定其散射强度IRRS,扣除空白溶液的散射强度,RES的质量浓度在0.05~5.0mg·L-1范围内与散射强度差ΔI呈线性关系。RES的检出限(3s/k)为15μg·L-1。应用此方法测定了葡萄叶和虎杖中RES的含量。所得结果与高效液相色谱法测得的结果相符。用标准加入法进行回收试验,测得回收率在96.0%~104%之间。测定值的相对标准偏差(n=5)在1.7%~4.3%之间。对反应体系的RRS增强的机理也进行了探讨。

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 FeCl3to form prussian blue,of which the intensity of its RRS is increased abruptly.Values of RRS intensity IRRSare measured at the RRS maximum of 314nm,values ofΔIRRS(found by substracting blank value from values of IRRS)are found to keep linear relationship with mass concentration of RES in the range of 0.05-5.0mg·L-1.Detection limit(3s/k)found for RES is 15μg·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.