Abstract
Currently, microextraction is being used more and more for aqueous sample analysis. The microextraction technique is environmentally-friendly, less expensive, and simple to operate. In the study a microextraction technique termed as liquid-liquid-liquid microextraction (LLLME) was implemented to extract sulfonamides, chlorophenols, nitrophenols, and alkylphenols in water. The LLLME technique can control the analytes into uncharged or charged species by pH adjustment, the target compounds were extracted from the donor phase (i.e., a water sample) into the organic phase and then extracted into the acceptor phase (i.e., the extractant). The extracted target analytes in the donor phase were directly separated and quantitated by high performance liquid chromatography (HPLC). To pursue optimum condition in LLLME, extraction parameters dominating extraction efficiency were investigated by theoretical considerations. The LLLME technique under dynamic mode and non-equilibrium consideration was applied for determination of these target analytes in water. The univariant method was conducted to identify extraction parameters for the designation of parameter settings in this dynamic LLLME technique. Relative standard deviation, coefficient of estimation, and detection limit were realized to assess analysis performance under selected parameter settings. The parameter settings of LLLME close to optimization was responsible for an acceptable extraction efficiency. In addition, real field water samples were analysed to demonstrate the practical applicability. The results suggested that matrix effect, interfering in the transport of target compounds from the donor phase through the organic phase and finally into the acceptor phase, was limited. Consequently, the study reachable of the determination confirms LLLME combined with HPLC to be robust to monitoring these target analytes in trace levels.