Solid Phase Extraction Using Modified Magnetic Iron Oxide Nanoparticles for Extraction and Spectrofluorimetric Determination of Carvedilol in Human Plasma Samples

A new analytical approach was developed involving magnetic solid–phase extraction and spectrofluorimetric determination of carvedilol in human plasma samples. A plasma sample was prepared and adjusted to pH 8.2–10, then carvedilol was quickly extracted using iron oxide magnetic nanoparticles modified by the surfactant cetyltrimethylammonium bromide and determined applying spectrofluorimetry at 354 ± 3 nm after excitation at 241 ± 3 nm. Experimental conditions, such as the amount of nanoparticles and cetyltrimethylammonium bromide, pH value, standing time and desorption solvent type and volume have been adjusted to optimize the extraction process and to obtain analytical characteristics of the method. Linearity was observed in the analyte concentration range of 2.0–125 ng/mL with correlation coefficients (r) of 0.999. The method showed good precision and accuracy, with intra– and inter–assay precisions of less than 7.0% at all concentrations. Standard addition recovery tests were carried out, and the recoveries ranged from 94.4% to 100.7%. The limits of detection and quantification were found to be 0.67 and 2.24 ng/mL. The method was applied to the determination of carvedilol in human plasma samples