Rapid derivatization and extraction of paraben preservatives by fast syringe-assisted liquid–liquid microextraction and their determination in cosmetic and aqueous sample solutions by gas chromatography

Abstract

In this work, a very rapid method is developed for the simultaneous derivatization and extraction of some parabens in aqueous sample solutions. This method termed as fast syringe-assisted liquid–liquid microextraction is based upon the dispersion of the extraction solvent in the aqueous sample solution and separation of these phases by using a nylon syringe filter after emulsification. By the implementation of this method, the overall derivatization and extraction time is just about 90 s, it is centrifuge-free, and by filtration of the acceptor phase, the method provides a high purification. In order to achieve the best extraction efficiency, optimization of the variables affecting the method is carried out. Under the optimal conditions, the method was found to be linear over the range of 2.0–5000 ng mL⁻¹ with the coefficient of determination (r²) in the range of 0.996–0.998. It provided low limits of detection (0.5–1 ng mL⁻¹), good extraction repeatabilities (RSDs below 9.4%, n = 5), and enrichment factors in the range of 128–147. Finally, the developed method is used for the determination of paraben preservatives in cosmetic (cream and lipstick) and water (tap water and river water) sample solutions.