Identification of co-existing cationic surfactants with preliminary separation on silica HPTLC plates using mixed aqueous sodium chloride-ethanol as eluent

A new high-performance thin-layer chromatographic system comprising of silica gel 60 HPTLC plates as stationary phase and ethanol-5% aqueous sodium chloride (8:2) as mobile phase has been identified as most suitable for separation of quaternary mixture of cationic surfactants. Separation efficacy of developed method has been established by obtaining well-resolved densitogram of separated spots. To check the versatility, effects of presence of metal cations, inorganic anions, amino acids, vitamins and non-ionic surfactants as impurities were also examined. The chromatographic parameters like Delta(RF) , separation factor (a), resolution (R-S)and limit of detection were also calculated. The proposed method is applicable for the identification of surfactants in eye drops and Colgate Plax mouthwash.