Simultaneous separation of nine surfactants of various types by HPLC with evaporative light scattering detection.

A simultaneous separation of cationic, amphoteric and nonioinc nine surfactants (DMDS, DMDP, DMDM, DMDL, BZC, CDE, A/O, SUNC, IMD) has been performed by a reverse phase-HPLC method utilizing a single J'sphere ODS (250mmx4.6mm, 4mum) column and a methanol-water containing 0.2% TFA eluent system within 60min. The observed precision in determination of concentration was less than 5% R.S.D., which revealed that ELSD was an effective tool to detect the various studied surfactants of low volatility without chromophore. In addition, the detection limits were in the concentration range of 3.5-10mug/mL, and the calibration curves, i.e. the log-log plots, were linear in the working range of 5-4600mug/mL with the slopes of 1.321-1.668. The application of the analytical procedure to three household products without pretreatment supported that the presented chromatographic method was simple to be practical for a routine analysis of commercial products.