间接荧光法测定维生素C  

Determination of Ascorbic Acid by Indirect Fluorimetry

作　　者：童裳伦[1] 项光宏[1] 刘维屏[1] 

机构地区：[1]浙江大学环境科学研究所,浙江杭州310029

出　　处：《光谱学与光谱分析》2005年第4期598-600,共3页Spectroscopy and Spectral Analysis

基　　金：国家自然科学基金;浙江省自然科学基金;浙江省分析测试基金资助项目

摘　　要：实验发现,抗坏血酸在水溶液中能将无荧光的铈(Ⅳ)离子还原成能发射特征荧光的铈(Ⅲ)离子,加入六偏磷酸钠溶液,可使体系的荧光强度大大增强,由此建立了灵敏间接测定抗坏血酸的新方法。用1cm石英比色池在激发和发射波长分别为30 3和340nm处测定其荧光强度;抗坏血酸在1 .0×10 -7～8 0×10 -6mol·L-1浓度范围内与体系的荧光强度呈良好的线性关系,相关系数为0 . 9997,检出限为1 .6×10 -8mol·L-1(S/N =3)。Experiments indicated that cerium( IV) ion which could not emit fluorescence was deoxidized by ascorbic acid to cerium(III) ion which could emit its characteristic fluorescence in water solution, while sodium hexametaphosphate added could greatly enhance the fluorescence intensity of the system. From this, an indirect sensitive method for determining ascorbic acid was developed. The fluorescence intensity of the system was measured in a I cm quartz cell with the excitation and emission wavelengths of 303 and 340 nm, respectively. The results showed that the fluorescence intensity of the system presented a linear relationship with the concentration of ascorbic acid in the range of 1.0 x 10(-7)-8.0 x 10(-6) mol(.)L(-1), the correlation coefficient r was 0.999 7, and the detection limit(S/N = 3) was 1.6 x 10(-8) mol(.)L(-1). The presented method was used to determine ascorbic acid sample and vitamin C tablet, and the results were satisfactory.

关 键 词：荧光法测定 维生素C 抗坏血酸 荧光强度 六偏磷酸钠 实验发现 铈(Ⅲ) 铈(Ⅳ) 间接测定 发射波长 线性关系 浓度范围 相关系数 水溶液 检出限 离子 中能 

分 类 号：O657.3[理学—分析化学] S153.62[理学—化学]