Paim Ana Paula S, Almeida Cristina M N V, Reis Boaventura F, Lapa Rui A S, Zagatto Elias A G, Costa Lima José L F
Centro de Energia Nuclear na Agricultura, Universidade de São Paulo, Av. Centenário 303, P.O. Box 96, 13400-970 Piracicaba, São Paulo, Brazil.
J Pharm Biomed Anal. 2002 Jun 15;28(6):1221-5. doi: 10.1016/s0731-7085(02)00018-3.
A flow procedure for the determination of ascorbic acid in pharmaceutical formulations exploiting potentiometric titration is described. The method is based on the reduction of IO3- by ascorbic acid and the detection was carried out employing a flow-through ion selective electrode for iodide. The flow network controlled by a microcomputer was designed to implement multicommutation for ease of operation and robustness. The titration system allowed the determination of ascorbic acid in pharmaceutical formulations with concentrations ranging from 7.5 to 15.0 mmol l(-1). No significant differences at the 95% confidence level were observed in comparison with results obtained by a manual procedure. Merit figures of results such as a relative standard deviation of 1.0% (n=6) and a reagent consumption of 21.4 mg IO3- per determination were obtained.
描述了一种利用电位滴定法测定药物制剂中抗坏血酸的流动程序。该方法基于抗坏血酸对IO3-的还原，并采用流通式碘离子选择性电极进行检测。由微型计算机控制的流动网络被设计用于实现多通道换向，以简化操作并提高稳健性。该滴定系统能够测定浓度范围为7.5至15.0 mmol l(-1)的药物制剂中的抗坏血酸。与手动程序获得的结果相比，在95%置信水平下未观察到显著差异。获得了诸如相对标准偏差为1.0%（n = 6）以及每次测定消耗21.4 mg IO3-的结果的品质因数。
