摘要
报道了一种用离子色谱分析维生素 Ｃ、亚硫酸根和硫代硫酸根离子的新方法。在这种方法中采用了四价铈柱后氧化还原反应和三价铈荧光检测法。
An ion chromatographic method was used to separate the species of L\|ascorbic acid, sulfite and thiosulfate in their mixtures. This method is based on the separation of each anion in their mixtures by using a separation column, and then on the fluorimetric measurement of cerium (Ⅲ) formed by a postcolumn reaction of cerium (Ⅳ) with the species of L\|ascorbic acid, sulfite and thiosulfate in the effluent. The optimal conditions for separating and determining the above three species have been established. By using a 3 mmol/L carbonate eluent, the species of L\|ascorbic acid, sulfite and thiosulfate could be eluted at the proper retention times of 1.7, 2.6 and 5.0 min, respectively, and these three anions could be separated completely. The effects of the concentrations of cerium (Ⅳ) and sulfuric acid in the postcolumn reaction solution on the chromatographic peak\|height were tested in order to obtain the optimal peak\|height. It was found that the peak\|height at first increases rapidly with an increase in the concentration of cerium (Ⅳ) and sulfuric acid respectively up to a certain concertation, then increases slowly. These critical concentrations of cerium (Ⅳ) and sulfuric acid also depend on the amount of the analyte injected. Meanwhile the baseline signals of the sepectra increase with an increase in the concentration of cerium (Ⅳ). Some concentrations above the critical concentration of sulfuric acid could be selected as the optimal concentration of sulfuric acid, but the concentration of cerium (Ⅳ) should be optimized by establishing a compromise between the higher peak\|height and the lower baseline signal. The detection limit of this method was found to be 1 μmol/L for thiosulfate when an amount of 100 μL analyte was injected.
出处
《色谱》
CAS
CSCD
北大核心
1999年第5期480-482,共3页
Chinese Journal of Chromatography
关键词
离子色谱
维生素C
测定
ion chromatography, L\|ascorbic acid,sulfocompound,postcolumn oxidation\|reduction reaction
