茜素红-CTMAB离子缔合阻滞效应吸光光度测定磺胺嘧啶

Spectrophotometry Determination of Sulfadiazine Based on Its Blocking Effect on the Ion Association of Alizarin Red and CTMAB

在疏水力作用下，水溶液中的茜素红与十二烷基三甲基溴化铵（CTMAB）以摩尔比1：1反应形成紫色离子缔合物，该缔合物溶液在553nm处有最大吸收．在该溶液中加入磺胺嘧啶，会使溶液退色而吸光度减小，而吸光度减小的程度与磺胺嘧啶的浓度成正比关系．据此，建立了一种茜素红-CTMAB离子缔合阻滞效应吸光光度测定磺胺嘧啶的新方法．用该方法对磺胺药片测定，回收率在98．2％～98．9％，线性范围为0．225--2．00g·L^-1，检出限为0．025g·L^-1，相对标准偏差为0．2％．

Alizarin red and CTMAB formed ion association complex at the ratio of 1：1 in the aqueous. The ion association complex was purple due to hydrophobic force, and it is with a maximum absorption at 553 nm. But sulfadiazine blocked the association of alizarin red and CTMAB. When sulfadiazine was added to the association complex solution, purple faded and solution absorbency reduced, and the absorbency reducing degree was directly proportional to the concentration of sulfadiazine. Thus, a determination method of sulfadiazine by spectrophotometry was established based on its blocking effect on the ion association of alizarin red and CTMAB. Sulfa tablets were measured with the method. The recovery rates by standard additions ranged from 98.2%98.9%. The linear range was from 0. 225 g.L^-1to 2.00 g.L^-1. The determination limit was 0. 025 g.L^-1, and RSD was 0.2%.