Analysis of estrogens in water by magnetic octadecylsilane particles extraction and sweeping micellar electrokinetic chromatography

A method based on magnetic separation was developed for the extraction of several estrogens (including diethylstilbestrol, estrone and estriol) in water followed by sweeping micellar electrokinetic chromatography (MEKC) analysis with UV detection. Novel magnetic octadecylsilane (ODS) particles were prepared using a silanization method with octadecyl trimethoxysilane as the surface modification reagent of magnetic Fe₃O₄ particles. Octadecyl trimethoxysilane was covalently immobilized on the magnetic iron oxide particles. The particles were used as the sorbents in the magnetic separation for the extraction of trace amounts of estrogens from water. The extraction condition and efficiency of the particles for the estrogens were investigated. Combining the magnetic ODS particles extraction and sweeping MEKC with UV detection, the estrogens at concentrations as low as ng/mL in water can be detected without interference from other substances in the sample matrix.