Dendritic Poly (amidoamine) Functionalized with Magnetic Nanoparticles as Sorbent for Simultaneous Magnetic Solid-Phase Extraction of Miconazole, Clotrimazole and Tioconazole Followed by Determination via HPLC-UV

In this study, an attempt was made to synthesize a new sorbent based on the second generation of silica coated magnetic poly(amidoamine) (Fe3O4@SiO2@PAMAM) to improve the performance of magnetic solid phase extraction (MSPE) of some antifungal drugs including miconazole, clotrimazole and ticonazole in various real samples such as urine and human plasma. The extracted analytes were measured by high performance liquid chromatography equipped with ultraviolet detection (HPLC-UV). Field emission-scanning electron microscopy (FE-SEM), X-ray diffraction analysis (XRD), Thermogravimetric analysis (TGA), Transmission electron microscopy (TEM) and Fourier transform-infrared spectroscopy (FT-IR) were used to study the morphology and structure of the prepared sorbent. The various factors such as: extraction time, sorbent amount, solvent desorption volume, desorption time, ionic strength and pH were studied and optimized. The method is validated according to ICH guidelines with respect to precision, accuracy, linearity, specificity, robustness, and limits of detection and quantification. Under the optimized condition, the linearity of the method was in the range of 1–500 µg L-1 (miconazole= 1-200 µg L-1, clotrimazole = 1-500 µg L-1 and ticonazole = 1-200 µg L-1). The obtained correlation coefficients (r^2) were between 0.9871-0.9977. The limits of detection (LODs) were also calculated to be 0.14-0.18 µg L-1 (miconazole= 0.16 µg L-1, clotrimazole = 0.18 µg L-1 and ticonazole=0.14 µg L-1). The limits of quantification (LOQs) were also in the range of 0.46-0.60 µg L-1 for the selected analytes. The relative standard deviations (RSDs%), were obtained in the range of 4.6 to 5.9%. Moreover, the calculated enrichment factors were between 85 and 93. The proposed method was also employed for the analysis of various real samples such as urine and plasma samples. The obtained recoveries indicated that the method was useful and applicable in complicated real samples