Magnetic solid-phase extraction of rose bengal using iron oxide nanoparticles modified with cetyltrimethylammonium bromide

Magnetic solid phase extraction (MSPE) based on cetyltrimethylammonium bromide (CTAB)-coated magnetic iron oxide nanoparticles (C-MIONPs) was investigated for the separation, preconcentration and determination of Rose Bengal (RB) in aqueous solutions. The influences of different analytical parameters such as pH, temperature, ionic strength, volume of desorbent solvent, amount of adsorbent and interfering ions in the adsorption of RB on C-MIONPs were investigated. The RB adsorption on C-MIONPs follows Langmuir isotherm. The sizes of C-MIONPs were in the range of 20–80 nm. The method was capable of determining RB concentration in the range of 0.01–1.20 μg ml −1 . The limit of detection (LOD) of RB based on three times the standard deviation of the blank (3Sb) was found to be 5.91 × 10–3 μg ml −1 (n = 8). The relative standard deviation (RSD) for 0.3 μg ml −1 and 0.8 μg ml −1 of RB were 4.1% and 1.1%, respectively. The proposed method was applied to the determination of RB in Brucella Antigen solution and water samples from the Karoon River.