含有不同浓度吐温－80的中草药注射液，在一定的波长下用紫外分光光度计测其相应的吸收度。由吸收度－表面活性剂物质的对数关系曲线的突变点，得知药液中吐温－80的临界胶束浓度（CMC）。为中草药注射液中吐温－80的最佳用量，提供定量的参考标准。

Ultraviolet spectrophotomety was used to determine Tween-80 critical micell concentration (CMC) in different Chinese herbal medicine injections. Studies on the concentration of iodine solution and wavelength suitable for the determinntion were carried out. This method is quick and accurate and can be used for the quality control of such preparation.