Determination of Rhodamine B in Food Samples by Fe3O4@ Ionic Liquids-β-Cyclodextrin Cross Linked Polymer Solid Phase Extraction Coupled with Fluorescence Spectrophotometry.

Fe3O4@Ionic liquids β-cyclodextrin polymer(Fe3O4@ mono-6- deoxy-6- (1-ethyl- imidazolium)-β-cyclodextrin iodide polymer, ILs-β-CDCP) was prepared. A novel method based on Fe3O4@ILs-β-CDCP solid phase extraction coupled with fluorescence spectrophotometry for Rhodamine B (RhB) determination, was investigated. Results were shown that RhB was adsorbed on Fe3O4@ILs-β-CDCP and eluted with sodium dodecyl sulfate (SDS) (1.0%) rapidly. Different parameters, such as pH, adsorption time and volume, eluent volume and time were studied. This method introduced linearity for RhB between 0.01-9.00 μg/mL-1 , the limit of detection was 5.2 ng/mL-1 , correlation coefficient (R) was >0.9987 and the relative standard deviation (RSD) was 3.1% (n = 3, c = 4.00 μg/mL). The mechanism of adsorption of RhB on Fe3O4@ILs-β-CDCP was studied through the FTIR analysis and the inclusion constant of Fe3O4@ILs-β-CDCP-RhB. This method was applied successfully for determination of RhB in real samples with satisfactory results.