共振瑞利散射光谱法测定药物中利福平——基于甲基紫的络合反应

Resonance Rayleigh Scattering Spectrometric Determination of Rifampicin——Based on Its Complex Reaction with Methyl Violet

在pH9．73的Tris-盐酸缓冲介质中，一定量的利福平与1．0×101mol·L^-1甲基紫溶液2．5mL反应生成的络合物，产生共振瑞利散射光谱，在其最大共振光散射峰波长381nm处测定共振瑞利散射的强度JRRS。利福平的质量浓度在0．823mg·L^-1以内与样品及空白溶液的散射强度值之差（ΔIRRS）呈线性关系，方法的检出限（3s／k）为0．0039mg·L^-1。方法用于药物中利福平含量的测定，测定结果与药典法测得结果相符，回收率在99．0％～102％之间，测定值的相对标准偏差（n=6）在0．8oA～1．1％之间。

In a Tris-HCl buffer medium of pH 9.73, an appropriate amount of rifampicin was reacted with 2.5 mL of 1. 0 × 10^-3 mol · L^-1 methyl violet solution, to form a complex and producing resonance Rayleigh Scattering （RRS）, the intensity （IRRs） of which was measured at the wavelength of scattering peak （381 nm）. Values of ΔIRRS [ IRRS （sample）- IRRS （blank）] was found to keep lenear relationship with values of mass concentration of rifampicin in the range within 0. 823 mg · L^-1 , with limit of detection （3s/k） of 0. 003 9 mg · L^-1. The proposed method was applied to the determination of rifampicin in its drug samples, giving results checked quite well with the results found by the method of pharmacopeia. Values of recovery and RSD＇s （n=6） found were in the ranges of 99.0%-102% and 0.8%-1.1% respectively.