Determination of cationic and nonionic surfactants using LC/MS

Cosmetics are mixtures of some surfactants, oils and other ingredients. A novel analytical method that requires no prolonged pretreatment to determine various different surfactants individually in mixtures is needed. We previously reported a new and simplified analytical method for mixtures of anion and amphoteric surfactants using liquid chromatography/ mass spectrometry (LC/MS). In this study, we developed a method that made it possible to determine cationic and nonionic surfactants individually in mixtures. To analyze nonionic surfactants, it was necessary to prepare the best condition for each group with similar molecular structures. We confirmed that this method was applicable for the determination of cationic and nonionic surfactants individually in several cosmetic lotions and creams.