Assay of Niclosamide by Resonance Light Scattering Technique with Cetyltrimethylammonium Bromide

Abstract

A sensitive assay of niclosamide was developed based on the measurement of the enhanced resonance light scattering signals of cetyltrimethylammonium bromide by the addition of trace amount of niclosamide. Under the acid conditions, the interaction of niclosamide with cetyltrimethylammonium bromide results in great enhanced resonance light scattering signals, owing to the interaction between niclosamide and the cationic surfactants. It was found that the enhanced resonance light scattering intensity was proportional to the concentration of niclosamide in the range of 2.5 × 10^-7 to 1.0 × 10^-5 mol/L with a detection limit of 4.7 × 10^-8 mol/L. This method was simple, rapid and economical. The developed method was applied to the determination of niclosamide in real samples with satisfactory results.