Solid-phase extraction of stanozolol abuse in athletes using a novel magnetic molecularly imprinted polymer sorbent

This study demonstrates the successful application of a new magnetic molecularly imprinted polymer sorbent for the selective and efficient extraction of stanozolol, followed by detection using liquid chromatography-mass spectrometry. To fabricate the magnetic sorbent, the surface of iron oxide nanoparticles was modified using methacrylic acid. Subsequently, these modified particles served as the core for synthesizing the magnetic molecularly imprinted polymer shell. The resulting sorbent was successfully characterized using scanning electron microscopy, Fourier-transform infrared spectroscopy, vibrating sample magnetometry, thermogravimetric analysis and N2 adsorption-desorption methods. The magnetic molecularly imprinted polymer sorbent exhibits superior extraction performance due to its high specificity and affinity for stanozolol, resulting from the imprinting process. Under optimal experimental conditions, the method achieved a calibration range of 0.4–25 ng mL−1, with an impressive detection limit of 0.02 ng mL−1. The novel extraction method exhibited excellent reproducibility and high selectivity, making it an attractive tool for the detection of stanozolol abuse. The practical utility of this methodology was successfully demonstrated through analysis of athlete urine samples, with recovery rates ranging from 92.4 % to 106.2 %.