Determination of Rhodamine B in Food Using Ionic Liquid–Coated Multiwalled Carbon Nanotube–Based Ultrasound-Assisted Dispersive Solid-Phase Microextraction Followed by High-Performance Liquid Chromatography

A modified Quick, Easy, Cheap, Effective, Rugged, and Safe method based on ultrasound-assisted dispersive solid-phase microextraction (dSPME) was developed for the determination of rhodamine B (RhB) in food samples. In this study, ionic liquid–coated multiwalled carbon nanotube (IL-MWCNT) was first used as dSPME material for the preconcentration of analyte. Several experimental parameters, including the type of ILs, the ratios of MWCNTs and ILs, amount of sorbent, extraction time, pH and ionic strength of sample solution, and desorption conditions, were evaluated. Under optimal experimental conditions, good linearity was observed in the range of 1.0–100.0 ng/mL with the correlation coefficient of 0.9978. The present method was applied to the analysis of different beverage and chili oil samples, and the recoveries of RhB obtained were in the range of 85.1–96.0 %. The results showed that the proposed method was a rapid, convenient, and feasible method for the determination of RhB in food samples.