在pH 6.92的Tris-盐酸缓冲溶液中,维多利亚蓝B与利福平生成络合物,最大吸收波长为562 nm。利福平的浓度在8.0×10-6mol·L-1范围内符合比耳定律,表观摩尔吸光率为1.86×105L·mol-1·cm-1。方法用于利福平胶囊中利福平含量的测定,测定值与标示量相一致。加标回收率在98.2%~100%之间,相对标准偏差(n=6)均小于1.5%。

In a Tris-HCl buffer solution of pH 6.92, a complex was formed by the reaction of rifampicin with victoria blue B, having its absorption maximum at the wavelength of 562 nm. Beer′s law was kept in the range within 8.0×10-6mol· L-1, with apparent molar absorptivity of 1.86×105L·mol-1·cm-1. The proposed method was used in the determination of rifampicin in its capsules, and the results obtained were in conformity with the labeled values. Values of recovery found by standard addition method were in the range of 98.2%-100% with RSD′s (n=6) less than 1.5%.