Screening Design of Experiment Applied to Dispersive Liquid-Liquid Microextraction of UV Filters from Water

Abstract

A Plackett-Burman factorial design (PBD) has been used for the optimization of dispersive liquidliquid microextraction (DLLME) of UV filters from water. The experimental procedure included a DLLME sample preparation prior to high-performance liquid chromatography triple quadrupole mass spectrometry (HPLC-MS/MS) measurements. The variables of the DLLME process for simultaneous preconcentration of UV filters (avobenzone and octocrylene) have been studied using PBD with twelve experimental runs. Several experimental variables including the extractant type, pH value, the disperser type, extractant volume, disperser volume, vortexing/sonication, centrifugation speed, reconstitution solvent, salt content, temperature, and centrifugation time were considered in the optimization process. PBD results revealed the most important variables that affected the extraction efficiency (EF). The first three most influential variables, as showed using a Pareto graph, were in the following order: the extractant volume > the disperser type > the extraction temperature. Based on the main effects plot, it was revealed that some variables (pH value, the disperser type, extractant volume, temperature, centrifugation speed, salt content) increased over the experimental domain, while the others (the extractant type, disperser volume, vortexing/sonication, centrifugation time, reconstitution solvent) decreased.