流动注射在线氧化荧光分析法测定柳氮磺吡啶

研究了硫酸介质中，高锰酸钾氧化柳氮磺吡啶（SASP）体系的荧光特性，结合流动注射进样技术，建立了流动注射在线氧化荧光分析测定SASP的新方法。SASP本身不发荧光，但在硫酸介质中与高锰酸钾反应后可产生1种有强荧光的产物（λex=301 nm，λem=366 nm）。在优化条件下，SASP的质量浓度在1.2×10-5~2.0×10-3 g/L范围内与相对荧光强度呈良好线性，相关系数为0.999 6。方法的检出限为3.0×10-6 g/L，对1.2×10-4 g/L的SASP标准溶液平行测定11次的相对标准偏差为0.6%。该法简单、快速、灵敏度高、选择性好，可用于药物制剂中SASP含量的直接分析。

Determination of Sulfasalazine by Flow Injection On-line Oxidizing Fluorophotometric Method

The fluorescence characteristics of sulfasalazine(SASP) oxidized by potassium permanganate in sulfate acid medium were studied.The result indicated that SASP can react with potassium permanganate in sulfate acid medium to produce a strong fluorescent species(λex=301 nm,λem=366 nm).Based on this phenomenon,a novel on-line oxidizing fluorescent method combined with flow injection technique was established for the determination of SASP.The experimental conditions affecting the fluorescence intensity of the system were investigated.The optimized experimental conditions were as follows: potassium permanganate concentration: 2.0×10-3 mol/L;sulfate acid: 2.0 mol/L;flow rate: 1.2 mL/min;length of mixing tube: 50 cm.Under the optimal experimental conditions,the calibration curves were linear in the range of 1.2×10-5-2.0×10-3 g/L with detection limit of 3.0×10-6 g/L.The relative standard deviation(RSD,n =11) was 0.6% for the determination of 1.2 ×10-4 g/L SASP standard solution.The proposed method had the advantages of simplicity,rapidity,high sensitivity and selectivity,and was successfully applied in the quantitative determination of SASP in enteric-coated tablets with recoveries of 96%-107%.