在pH 3.70的B-R缓冲溶液中,盐酸西布曲明与溴酚蓝以摩尔比1比2反应形成具有正吸收和负吸收的离子缔合物,最大正吸收波长为436 nm,最大负吸收波长为590 nm,线性范围分别在3.4×10-6mol·L-1(正吸收)、3.8×10-6mol·L-1(负吸收)以内,表观摩尔吸光率为1.83×105L· mol-1·cm-1(正吸收)、5.51×104L· mol-1·cm-1(负吸收),据此建立了测定盐酸西布曲明含量的分光光度法。方法用于合成样品及尿样中盐酸西布曲明的测定,回收率在96.8%~102.5%,相对标准偏差(n=6)在0.9%~1.7%之间。

In a B-R buffer solution of pH 3.70, an ionic association complex, with molar ratio of 1 to 2 was formed by the reaction of sibutramine hydrochloride with bromophenol blue, having the positive absorption maxmum at the wavelength of 436 nm and negative absorption maximum at 590 nm. Ranges of linearity found at the 2 absorption maxima were within 3.4×10-6mol·L-1 and 3.8×10-6mol·L-1, with their values of apparent molar absorptivity of 1.83×105L· mol-1·cm-1 and 5.51×104L·mol-1·cm-1 respectively. Based on these facts, a method of spectrophotometric determination of sibutramine hydrochloride was proposed. The present method was applied to the determination of sibutramine hydrochloride in simulated samples and urine samples, giving values of recovery and RSD′s (n=6) in the ranges of 96.8%-102.5% and 0.9%-1.7% respectively.