Tetraiodophenolsulfonphthalein as a spectral substitute to characterize the complexation between cationic and anionic surfactant

The complexation of cetyltrimethyl ammonium bromide (CTAB) with sodium dodecyl sulfate (SDS) with sodium dodecyl benzene sulfonate (SDBS), with tetraiodophenolsulfonphthalein (TIPST) as a spectral substitute was investigated at pH 5.89 and 8.30 by the microsurface adsorption-spectral correction (MSASC) technique. The aggregations of TIPST, SDS, and SDBS on CTAB obeyed the Langmuir isothermal adsorption. The aggregates TIPST-CTAB, TIPST2-CTAB(3), SDS3-CTAB(2), and SDBS3-CTAB(2) were formed at 20degreesC and the binding constants of all the aggregates were determined. The replacement of TIPST-binding CTAB monomer with SDS or SDBS at pH 5.89 was applied to the quantitative determination of anionic detergent (AD) in water with satisfactory recovery. (C) 2004 Elsevier Inc. All rights reserved.