Sastry C S, Naidu P Y
Foods and Drugs Laboratories, School of Chemistry, College of Science and Technology, Andhra University, Visakhapatnam 530 003, India.
Talanta. 1998 Aug;46(6):1357-62. doi: 10.1016/s0039-9140(98)00003-4.
Simple, selective and sensitive spectrophotometric methods are described for the determination of pentoxifylline, based on the haloform reaction with a known and excess of standard iodine solution under alkaline conditions. The excess of iodine is determined at pH 3.0 with metol-isoniazid (lambda(max)=620 nm; method A) or wool fast blue BL (lambda(max)=540 nm, method B). All the variables have been optimised and the reaction mechanisms presented. Regression analysis of Beer's law plots showed good correlation in the concentration ranges 4.0-24.0 and 0.4-2.4 mg ml(-1) for methods A and B respectively. No interferences were observed from excipients and the validity of the methods was tested by analysing pharmaceutical formulations. Recoveries were 99.0-100.0%. The concentration measurements were reproducible within a relative standard deviation of 1.0%.
本文描述了一种简单、选择性好且灵敏的分光光度法，用于测定己酮可可碱。该方法基于在碱性条件下，己酮可可碱与已知过量的标准碘溶液发生卤仿反应。过量的碘在pH 3.0时，用米吐尔 - 异烟肼（λmax = 620 nm；方法A）或耐尔蓝BL（λmax = 540 nm，方法B）进行测定。对所有变量进行了优化，并阐述了反应机理。比尔定律曲线的回归分析表明，方法A和方法B在浓度范围分别为4.0 - 24.0和0.4 - 2.4 mg ml⁻¹时具有良好的相关性。辅料未产生干扰，通过分析药物制剂对方法的有效性进行了测试。回收率为99.0 - 100.0%。浓度测量的相对标准偏差在1.0%以内，具有可重复性。
