Separation/Analysis Rhodamine B by Anion Surfactant/Ionic Liquid Aqueous Two-Phase Systems Coupled with Ultraviolet Spectrometry

Abstract

A novel method for the separation/analysis rhodamine B has been described. The ionic liquid (1-tetradecyl-3-methylimidazolium bromide)/anion surfactant (sodium dodecyl sulfate)/NaCl two-phase systems (ATPSs) is presented as a simple, rapid and effective sample pretreatment technique coupled with ultraviolet spectrometry for analysis rhodamine B in soft drink. The effects of parameters on the ATPSs extraction of rhodamine B such as amount of surfactant, ionic liquid and salt, pH, temperature, stabilization and centrifugal time have been studied in details. Under the optimized conditions, the linear range of calibration curve for rhodamine B was 0.05 - 7.0 μg·mL−1 and the detection limit was 3.2 ng·mL−1. The phase equilibrium and the mechanism of phase separation for ATPSs have been discussed. This method has been applied to the determination of rhodamine B in soft drink.