Polypyrrole/magnetic nanoparticles composite as an efficient sorbent for dispersive micro-solid-phase extraction of antidepressant drugs from biological fluids

In this study, polypyrrole/magnetic nanoparticles composites in the presence of two different dopants were synthesized with the aid of chemical oxidative polymerization process for dispersive-mu-solid phase extraction (D-mu-SPE). The synthesized magnetic sorbents were characterized by various techniques. The results exhibited that the nanocomposite modified by polypyrrole with sodium perchlorate as a dopant demonstrated higher extraction efficiency for citalopram (CIT) and sertraline (STR) as the model compounds. This nanosorbent in combination with high performance liquid chromatography-UV detection was applied for extraction, preconcentration and determination of CIT and STR in urine and plasma samples. The effect of various parameters on the extraction efficiency including: sample pH, amount of sorbent, sorption time, eluent and its volume, salt content, and elution time were investigated and optimized. The opted conditions were: sample pH, 9.0; sorbent dosage, 10 mg; sorption time, 7 min; elution solvent and its volume, 0.06 mol L-1 HCl in methanol, 120 mu L; elution time, 2 min and without addition of salt to the sample. The calibration curves were linear in the concentration range of 1800 mu g L-1. The limits of detection (LODs) were obtained in the range of 0.2-1.0 mu g L-1 for CIT and 0.30.7 mu g L-1 for STR, respectively. The percent of extraction recoveries and relative standard deviations (n = 5) were in the range of 93.4-99, 4.8-8.4 for CIT and 94-98.4, 4.3-9.2 for STR, respectively. Finally, the applicability of the method was successfully confirmed by the extraction and determination of CIT and STR in human urine and plasma samples. (C) 2015 Elsevier B.V. All rights reserved.