Dynamic liquid-phase microextraction of three phthalate esters from water samples and determination by gas chromatography

A fast and simple method, which involves dynamic liquid-phase microextraction followed by gas chromatography with flame ionization detection, has been developed to facilitate the identification and quantification of three phthalate esters (dimethyl phthalate (DMP), diethyl phthalate (DEP), and di-n-butyl phthalate (DnBP)) in water samples. Experimental parameters affecting the extraction efficiency, such as extraction solvent, solvent volume, dwell time and extraction frequency were investigated. Under the optimal conditions, the method yields a linear calibration curve over three orders of magnitude for the target analytes. The limits of detection of DMP, DEP and DnBP were 4.30, 0.66 and 0.43 ng mL−1, respectively, and relative standard deviations at the 100 ng mL−1 level were 6.4%, 5.4% and 5.2%, respectively (n = 6). Lake water, tap water and bottled mineral water samples were successfully analyzed using the proposed method.