Aggregation of a dye on a surfactant: Interaction of coomassie brilliant blue G250 with cetyltrimethylammonium bromide and determination of the cationic surfactant in water

The interaction of Coomassie brilliant blue G250 (CBBG) with cetyltrimethylammonium bromide (CTAB) has been investigated at pH 9.50 by the microsurface binding-spectral correction (MSASC) technique. The experiments confirmed that the aggregation of CBBG on CTAB obeys the Langmuir isothermal adsorption. The aggregate was characterized. Results showed that the monomer aggregate, CBBG(2)CTAB was formed at 30degreesC with a binding constant of 6.46 x 10(3). The aggregation was applied to the quantitative determination of the cationic surfactant in water samples with satisfactory results.