Filter-based emulsification microextraction as an efficient method for the determination of chlorophenols by gas chromatography.

In this work, an efficient microextraction method was applied for the extraction of some chlorophenols in water samples. This method, termed filter-based emulsification microextraction, is based on the dispersion of an extractant into an aqueous sample solution to accelerate the extraction process and the utilization of a Nylon syringe filter to break the emulsion. After phase separation, the method is coupled with gas chromatography as a final analyzer instrument. The overall derivatization/extraction time was about 90 s. The proposed method is centrifuge-free, and it also provides a suitable sample clean-up by filtration of the extracting phase. The effective parameters involved in the extraction method were optimized. Under the optimal experimental conditions, the method provided a good linearity in the range of 2.0-2000 ng/mL, extraction repeatabilities (relative standard deviations) below 9.4%, enrichment factors of 180-203, and limits of detection between 0.5 and 1.2 ng/mL.