Resonance light scattering method for the determination of anionic surfactant with acridine orange

The resonance Rayleigh scattering (RRS), second-order scattering (SOS) and frequency-double scattering (FDS) spectra of sodium dodecylbenzene sulfonate (SDBS) (anionic surfactant (AS)) with acridine orange (AO) system were studied. Experimental results showed that when λem = λex = 537 nm, the RRS peak of AO was greatly enhanced with the increase of SDBS concentration at a pH range of 1.8–4.0. The linear range of the calibration curve for SDBS was 0.028–8.71 mg L−1 with a detection limit of 8.36 μg L−1 when the AO concentration was 2.5 × 10−5mol L−1. The method has been applied to the determination of trace amount of AS in environmental water samples with satisfactory results. In addition, when λem = 321 nm and λex = 642 nm, the intensity of FDS was proportional to the SDBS concentration ranging from 0.014 to 8.71 mg L−1 and the correlation coefficient was 0.993 with a detection limit of 4.31 μg L−1; when λem = 642 nm and λex = 321 nm, the intensity of SOS was proportional to the SDBS concentration ranging from 0.050 to 8.71 mg L−1, and the correlation coefficient was 0.993 with a detection limit of 14.9 μg L−1.