Low toxic dispersive liquid-liquid microextraction using halosolvents for extraction of polycyclic aromatic hydrocarbons in water samples

A low toxic dispersive liquid-liquid microextraction (LT-DLLME) combined with gas chromatography-mass spectrometry (GC-MS) had been developed for the extraction and determination of 16 polycyclic aromatic hydrocarbons (PAHs) in water samples. In normal DLLME assay, chlorosolvent had been widely used as extraction solvents; however, these solvents are environmental-unfriendly. In order to solve this problem, we proposed to use low toxic bromosolvent (1-bromo-3-methylbutane, LD50 6150 mg/kg) as the extraction solvent. In this study we compared the extraction efficiency of five chlorosolvents and thirteen bromo/iodo solvents. The results indicated that some of the bromo/iodo solvents showed better extraction and had much lower toxicity than chlorosolvents. We also found that propionic acid is used as the disperser solvent, as little as 50 mu L is effective. Under optimum conditions, the range of enrichment factors and extraction recoveries of tap water samples are ranging 372-1308 and 87-105%, respectively. The linear range is wide (0.01-10.00 mu g L-1), and the limits of detection are between 0.0003 and 0.0078 mu g L-1 for most of the analytes. The relative standard deviations (RSD) for 0.01 mu g L-1 of PAHs in tap water were in the range of 5.1-10.0%. The performance of the method was gauged by analyzing samples of tap water, sea water and lake water samples. (C) 2010 Elsevier B.V. All rights reserved.