溴甲酚绿酸性染料比色法测定黄杨宁软胶囊含量

Assay of buxines soft capsules by colorimetry with bromocresol green

目的:建立黄杨宁软胶囊含量的酸性染料比色测定法。方法:软胶囊中黄杨宁在 pH 3.5的磷酸二氢钠缓冲液中与溴甲酚绿形成离子对,经氯仿萃取后在414 nm 波长下比色法测定吸收度,标准曲线法测定黄杨宁含量。结果:平行操作条件下,比色液在4 h 内稳定,符合 Beer 定律的线性范围为1.0～8.0μg·mL^(-1)(r=0.9997),平均回收率100.1%(n=15)。结论:溴甲酚绿酸性染料比色法测定黄杨宁准确灵敏,可用于黄杨宁含量测定。

Objective：To establish a colorimetric assay method for buxines soft capsules. Methods：The method was based on ion -pair complexes of buxines formed with bromocresol green（BCG） in pH 3.5 aqueous phosphate buffer solution. The complexes were extracted into chloroform for quantitative determination at 414 nm. The content of buxines soft capsules was determined with the corresponding calibration curve method. Results： The complexes in chloroform solution were stable within 4 h under parallel operating condition. Calibration curve obeyed Beer＇s law was in the concentration range from 1.0 to 8.0μg·mL^-1 with r = 0. 9997. The recovery for sample assay was 100. 1% （n = 15 ）. Conclusion：The colorimetric assay method for buxines soft capsules based on ion -pair complexes of buxines formed with bromocresol green is sensitive and accurate. It can be used for the quality control of buxines soft capsules.