Directly suspended droplet three liquid phase microextraction of diclofenac prior to LC

Directly suspended droplet liquid-liquid-liquid microextraction (LLLME) has been used to determine residues of diclofenac (2-[2-(2,6-dichlorophenyl) aminophenyl] ethanoic acid), in environmental water samples. In this technique a free suspended droplet of an aqueous solvent is delivered to the top-center position of an immiscible organic solvent floating on the top of an aqueous sample while being agitated by a stirring bar placed on the bottom of the sample cell. Recently, diclofenac was found as an environmental contaminant in sewage, surface, ground and drinking water samples. In the present work, diclofenac was extracted from water samples by LLLME and analysed by HPLC with UV detection at 281 nm. Factors such as organic solvent, extraction and back extraction times, stirring rate and the pH of acceptor and donor phases were optimized. Enrichment factor and detection limit (LOD, n = 7) were 102 and 0.1 mu g L-1, respectively. The linearity ranged from 0.5 to 2,000 mu g(-1) with a %RSD (n = 5) of 7.2 at S/N = 3. All experiments were carried out at room temperature (22 +/- 0.5 degrees C).