Development of a vortex-assisted ionic liquid microextraction method for the determination of aromatic amines in environmental water samples

Abstract

A vortex-assisted ionic liquid microextraction method coupled with ultra fast liquid chromatographic separation and detection was developed for the analysis of three aromatic amines, 4-chloroaniline, 1-naphthylamine and 4-aminobiphenyl, in environmental water samples. 1-Hexyl-3-methylimidazolium hexafluorophosphate [C₆MIM][PF₆] was used as the extraction solvent as it can disperse in water completely and quickly with the aid of vortex mixing. A dispersive solvent was not required. Several parameters such as type and volume of extraction solvent, vortex velocity, extraction time, centrifugation time, pH of sample solution and ionic strength in sample solution were investigated. Under the optimized conditions, the intra-day and inter-day precision of the proposed method were 2.3–3.5% (n = 5) and 2.8–5.3% (n = 5), respectively. The limits of detection and quantification were in the range of 0.24–0.57 μg L⁻¹ and 0.80–1.90 μg L⁻¹, respectively. The proposed method was applied in the determination of three aromatic amines in several real water samples. Acceptable recoveries of the analytes, ranging from 79% to 111% (the relative standard deviations ≤6.0%), were obtained.