Ultrasound-assisted ionic liquid dispersive liquid-phase micro-extraction: A novel approach for the sensitive determination of aromatic amines in water samples

Ultrasound-assisted ionic liquid dispersive liquid-phase micro-extraction was developed for the determination of four aromatic amines such as 2,4-dichloroaniline, 1-naphthylamine, 6-chloroanline and N,N-dimethylaniline. High-performance liquid chromatography coupled with UV detector was used for the determination of aromatic amines. In the novel procedure, 1-hexyl-3-methylimidazolium hexafluorophosphate [C6MIM] [PF6] was dispersed into the aqueous sample solution as fine droplets by ultrasonication, and which promoted the analytes more easily migrate into the ionic liquid phase. Variable affecting such as the volume of [C6MIM] [PF6], sample pH, ultrasonication time, extraction time, centrifuging time have been investigated in detail. The proposed method has been found to have excellent detection sensitivity with limits of detection (LOD, S/N =3) in the range of 0.17-0.49 mu g L-1 and precisions in the range of 2.0-6.1% (RSDs, n=6). This method has been also successfully applied to analyze the real water samples and good spiked recoveries over the range of 92.2-119.3% were obtained. (C) 2009 Elsevier B.V. All rights reserved.