Study on the Interaction between a Novel Ionic Liquid Probe and Anionic Surfactants Using Resonance Light Scattering Spectra and Its Analytical Application

The interaction between anionic surfactants (AS) and 1‐hexadecyl‐3‐methylimidazolium bromide C₁₆mim]Br was studied by using resonance light scattering (RLS) technique, UV‐Vis spectrophotometry and fluorometric methods. In Britton Robinson (BR) buffer (pH 6.0), C₁₆mim]Br reacted with AS to form supermolecular complex which resulted in enhancement in RLS intensity. Their maximum RLS wavelengths were all at 390 nm. Some important interacting experimental variables, such as the solution acidity, C₁₆mim]Br concentration, salt effect and addition order of the reagents, were investigated and optimized. Under the optimum conditions, quantitative determination ranges were 0.001–7 μg·mL^?1 for dodecyl sodium sulfate (SDS), 0.001–6 μg·mL^?1 for sodium dodecylbenzene sulfonate (SDBS) and 0.005–7 μg·mL^?1 for sodium lauryl sulfonate (SLS), respectively, while the detection limits were 1.3 ng·mL^?1 for SDS, 1.0 ng·mL^?1 for SDBS and 5.1 ng·mL^?1 for SLS, respectively. Based on the ion‐association reaction, a highly sensitive, simple and rapid method has been established for the determination of AS.