Ionic liquid for improved single-drop microextraction of aromatic amines in water samples

A new method was developed for the analysis of 1-naphthylamine, N,N-dimethylaniline and diphenylamine in water samples by improved single-drop microextraction with 1-butyl-3-methylimidazolium hexafluorophosphate ([C4MIM]PF6). Factors such as salt concentration, sample temperature, stirring rate, extraction time, pH and organic drop volume were systematically investigated. Under the optimized conditions, an excellent linear relationship was achieved in the range of 1.0-100 mu g L-1 for 1-naphthylamine, diphenylamine, and 0.5-100 mu g L-1 for N,N-dimethylaniline, respectively. The detection limits varied between 0.09-0.38 mu g L-1, and enrichment factors ranged from 13.7 to 116.3. The precision of the method was below 8.1% (RSD). It was successfully applied to the determination of these aromatic amines in water samples. The results demonstrated that this procedure represents an efficient and sensitive method for the analysis of aromatic amines in water samples.