Electro membrane extraction of sodium diclofenac as an acidic compound from wastewater, urine, bovine milk, and plasma samples and quantification by high-performance liquid chromatography

Electro membrane extraction (EME) as a new microextraction method was applied for extraction of sodium diclofenac (SDF) as an acidic compound from wastewater, urine, bovine milk and plasma samples. Under applied potential of 20 V during the extraction. SDF migrated from a 2.1 mL of sample solution (1 mM NaOH), through a supported liquid membrane (SLM), into a 30 mu L acceptor solution (10 mM NaOH), exist inside I he lumen of the hollow fiber. The negative electrode was placed in the donor solution, and the positive electrode was placed in the acceptor solution. 1-octanol was immobilized in the pores of a porous hollow fiber of polypropylene as SLM. Then the extract was analyzed by means of high-performance liquid chromatography (HPLC) with UV-detection for quantification of SDF. Best results were obtained using a phosphate running electrolyte (10 mM, pH 2.5). The ranges of quantitation for different samples were 8-500 ng mL(-1). Intra- and inter-day RSDs were less than 14.5%. Under the optimized conditions. the preconcentration factors were between 31 and 66 and also the limit of detections (LODs) ranged from 2.7 ng mL(-1) to 5 ng mL(-1) in different samples. This procedure was applied to determine SDF in wastewater. bovine milk, urine and plasma samples (spiked and real samples). Extraction recoveries for different samples were between 44-95% after 5 min of extraction. (c) 2012 Elsevier B.V. All rights reserved.