Silver Nanoparticles–Polyaniline Nanocomposite for Microextraction in Packed Syringe

A rapid, convenient and reliable method for microextraction in packed syringe (MEPS) of the loop diuretic furosemide (FUR) in urine along with high-performance liquid chromatography (HPLC) was developed. A nanocomposite based on silver nanoparticles/polyaniline (Ag-NPs/PANI) was synthesized and used as the MEPS packing material. This nanocomposite was prepared conveniently using interfacial polymerization without the need for any templates or functional dopants. The feasibility of the synthesized nanocomposites was examined by isolation of FUR from diluted urine samples. After extraction, the analyte was desorbed by 200 μL of methanol. It was then dried and the residue was dissolved in 30 μL of methanol and an aliquot of 25 μL was, finally, injected into the HPLC system. Important parameters influencing the extraction and desorption processes were optimized and 25 cycles of draw–eject gave maximum peak area, when desorption was performed. The linearity was studied by preconcentration of 5 mL of diluted urine sample spiked with a standard solution of FUR in the concentration range of 15–750 μg L−1. The coefficient of determination was satisfactory (r2 > 0.99) and the relative standard deviation (RSD %) value under the optimized condition was 8.8 %. The limit of detection and limit of quantification were 7 and 15 μg L−1, respectively.