Simultaneous analysis of anionic,amphoteric,nonionic and cationic surfactant mixtures in shampoo and hair conditioner by RP-HPLC/ELSD and LC/MS

摘要

A simple and simultaneous analysis method for four(anionic,amphoteric,nonionic,and cationic)classes of surfactants in shampoo and hair conditioner was newly developed.Analysis of the surfactants was performed using a reversed-phase HPLC(RPLC)combined with evaporative light scattering detection(ELSD)without any pre-treatment.An optimum analysis condition for the resolution of both four main surfactant mixtures used in shampoo and five main surfactants used in hair conditioner could be established under a gradient mobile phase condition with acetonitrile,tetrahydrofuran and water.The detection limits were 2.5-30 mu g mL~(-1)except for SLES(150 mu g mL~(-1)),and the calibration curves,i.e.the log-log plots,were linear in the working range of 2.5-5250 mu g mL~(-1)with R2 values of above 0.998.The observed precision was less than 5% R.S.D.The elution peaks were identified by a liquid chromatography-mass spectrometer(LC-MS)equipped with an electrospray interface operating in mixed-mode.