荧光光度法测定维生素C

Spectrofluorimetry method for determining ascorbic acid.

维生素 C与 2 ,3-二氨基萘 (DAN)在 p H=10 .2～ 10 .5时能发生缩合反应 ,生成强荧光的杂氮环缩合物 ,据此建立了一种简便、灵敏测定抗坏血酸的新方法 .在激发波长 4 0 0 nm,发射波长 5 2 0 nm处测定其荧光强度 .维生素 C浓度在 2～ 30 0μg· m L-1范围内与其荧光强度呈良好的线性关系 ,相关系数为 0 .9993,其检出限为 0 .6μg·m L-1(S/ N=3) .利用本法进行回收试验与样品测定都取得了令人满意的结果 .

Ascorbic acid(AA) can react with 2,3\|diaminonaphthalene(DAN) at pH=10.2～10.5, forming the fluorescent heterocyclic condensation product which emits strong fluorescent light. The fluorescence intensity has been measured in a 1\|cm quartz cell at excitation and emission wavelengths of 400 and 520 nm, respectively. Good linear relationship is obtained between the fluorescence intensity and AA concentration in the range of 2～300 μg·mL\+\{-1\} with a relevance coefficient of 0.9993 and detection limit(\%S/N\%=3) 0.6 μg·mL\+\{-1\}. The proposed method can be used in recovery test and sample determination, giving satisfactory results.