© 2022 Taylor & Francis Group, LLC.A microextraction method has been developed for the determination of rhodamine B (Rh-B) in water and cosmetics by separation and preconcentration with liquid microextraction based upon a switchable hydrophilic solvent and determination by spectrophotometry. The analyte was extracted into the triethylamine (TEA) phase using sodium hydroxide (NaOH) to convert protonated triethylamine carbonate (P-TEA-C) to triethylamine. Various analytical parameters such as the pH of the sample solution, extraction solvent volume, and sample volumes affecting the quantitative recovery values of rhodamine B were optimized. The limit of detection (LOD) and limit of quantification (LOQ) were 2.96 and 9.88 ng/mL, respectively. The developed method was successfully applied to the determination of rhodamine B and satisfactory recovery values were obtained. The developed approach is fairly fast and an environmentally friendly alternative for the separation and preconcentration of rhodamine B water and cosmetic samples.