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

An electrostatic self-assembly approach was employed to prepare Fe(3)O(4)/graphene oxide nanocomposites, and their application in the magnetic solid-phase extraction of polycyclic aromatic hydrocarbons from environmental samples was investigated. With the highly hydrophilic graphene oxide sheets and positively charged surface of the Fe(3)O(4) nanoparticles, the nanocomposites were synthesized through electrostatic interaction in aqueous solution. Simultaneously, the different loading amounts of Fe(3)O(4) onto the graphene oxide were easily controlled by changing the proportion of the initial precursors. The identity of the hybrid materials was confirmed using transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy and a vibrating sample magnetometer. Five polycyclic aromatic hydrocarbons were selected as model analytes to validate the extraction performance of the Fe(3)O(4)/GO nanocomposite as a MSPE sorbent. The excellent adsorption property was attributed to the dominant roles of π-π stacking interaction and hydrophobic interaction. After optimizing the conditions, the results indicated that the recoveries of these compounds were in the range of 76.8-103.2%, with relative standard deviations ranging between 1.7% and 11.7%; the limits of detection were in the range of 0.09-0.19 ng mL(-1).