Tailoring a new hyperbranched PEGylated dendrimer nano-polymer as a super-adsorbent for magnetic solid-phase extraction and determination of letrozole in biological and pharmaceutical samples

Abstract

A novel hyperbranched magnetic dendrimer was successfully fabricated and utilized as an efficient adsorbent for solid-phase extraction of letrozole from different media (plasma, urine, and tablet matrices) in this study. Iron oxide nanoparticles as magnetic cores were modified with PEGylated block-dendrimer polymer branches. The Fe3O4@SiO2/DAG/MMA/ED/Gly-PEGylated was characterized by a Vibrating sample magnetometer (VSM), Thermogravimetric analysis (TGA), Fourier-transform infrared spectroscopy (FTIR), and Scanning electron microscope (SEM) analyses. The average particle size was obtained as 47 ± 4.3 nm for the nano-adsorbent. The experimental parameters influencing the extraction efficiency of the letrozole, such as pH of the sample solution, and contact time were carefully examined and optimized. Moreover, the isotherm adsorption and kinetic studies demonstrated that the adsorption process was well fitted to Langmuir isotherm and Pseudo-first-order kinetic models, respectively. A maximum adsorption capacity of 20 mg g−1 was acquired based on the Langmuir model. Under optimal conditions, the suggested approach provided favorable linearity in the range of 0.1–15 μg L−1, low limits of detection (1.36 μg L−1), and quantification (4.54 μg L−1). The recoveries for spiking 1 μg L−1 of letrozole in plasma and urine samples and letrozole tablet were respectively, 75.6%, 98.4%, and 93.7%. Relative standard deviation values for plasma, urine, and tablet were respectively, obtained to be 1.1, 05, and 0.4. These results showed that the suggested technique was a potent analytical tool and a helpful alternative for common analysis of such medicines.