Magnetic solid-phase extraction of amoxicillin and doxycycline from water and urine samples based on cetylpyridinium chloride-modified FeO nanoparticles followed by spectrophotometric determination.

This research describes an easy, rapid, and inexpensive magnetic solid-phase extraction (MSPE) approach employing FeO magnetic nanoparticles modified with cetylpyridinium chloride (FeO@CPC/MNPs) for extracting amoxicillin (AMX) and doxycycline (DOX) after derivatization with 4-chloroaniline as a color reagent. The azo-coupling of AMX and DOX with the color reagent in the alkaline medium caused yellow and yellow-orange azo dyes with maximum absorption wavelengths of 435 and 438 nm, respectively. The UV-Vis spectroscopy was utilized to determine the target analyte after the extraction procedure.