Preconcentration and Spectrophotometric Determination of a Naphthalene Analog of Medetomidine Using Modified Maghemite Nanoparticles

A novel and sensitive extraction procedure using sodium dodecyl sulfate (SDS) modified maghemite nanoparticles (MNPs) as an efficient solid phase has been developed for removal, preconcentration, and spectrophotometric determination of trace amounts of a naphthalene analog of dexmedetomidine (4-(1-(na phthalene-1-yl)ethyl)-1Himidazole, NMED). The MNPs were obtained by a coprecipitation method, and their surfaces were furthermore modified by SDS. The size and morphological properties of the synthesized MNPs were determined by X-ray diffraction analysis, FT-IR, vibrating sample magnetometry, and scanning electron microscopy. NMED was adsorbed at pH 3.0. The adsorbed drug was then desorbed and determined by spectrophotometry at 280 nm. The calibration graph was linear in the range 1 x 10(-6)-1 x 10(-4) mol/L of NMED with a correlation coefficient of 0.989. The detection limit of the method for NMED determination was 3.7 x 10(-7) mol/L. The method was successfully applied to the determination of NMED in human urine samples.