A rapid method for the determination of six phthalates (PAEs) in water samples was established by dispersive liquid-liquid microextraction (DLLME) based on solidification of floating organic drop (SFO) coupled with high performance liquid chromatography (HPLC). The influences of the SFO-DLLME parameters on extraction efficiencies were studied. Dodecanol (extraction solvent, 20 μL) was added to the water samples (containing 20 g/L NaCl) at 60℃, and the solution was shaken for 1 min. The results showed that the six PAEs were linear in the range of 2-2000 μg/L with correlation coefficients (r) between 0.9995 and 0.9999. The limits of detection (S/N=3) of the six PAEs ranged from 0.3 to 0.6 μg/L. The proposed method was applied to the analysis of the seven water samples obtained from different sources (tap water, lake water, river water, waste water, sea water, plastic bottled pure water and mineral water), and some PAEs were detected. The recoveries of the six PAEs in the spiked water samples were 84.9%-94.5%, and relative standard deviations were 4.1%-6.8% at three levels of 10, 100 and 1000 μg/L. The method is an environmentally friendly and convenient method for the routine analysis of the PAEs in water samples.
Keywords: dispersive liquid-liquid microextraction (DLLME); high performance liquid chromatography (HPLC); phthalates (PAEs); solidification of floating organic drop (SFO); water samples.