测定如下:电位滴定法测定一系列阳离子表面活性剂溶液的氯离子或溴离子活性，其浓度覆盖预期胶束化浓度。绘制电位图作为浓度对数的函数；c.m.c.对应于这条曲线上的奇点。该方法适用于纯化的阳离子表面活性剂（氢氯化物和/或氢溴化物），其可溶于水且克拉夫特温度低于60摄氏度。

The determination is carried out as follows: Potentiometric determination of the chloride or bromide ion activity of a series of solutions of cationic surface active agents the concentration of which cover the expected micellization concentration. Plotting the graph of potential as a function of the logarithm of the concentration; the c.m.c. corresponds to the singularity on this curve. The method is applicable to purified cationic surface active agents (hydrochlorides and/or hydrobromides), which are soluble in water and which have a Krafft temperature below 60 degree Celsius.