Solid phase extraction using modified magnetite iron oxide nanoparticles for the extraction and spectrofluorimetric determination of metoprolol in different biological samples

A new analytical approach was developed involving magnetic solid–phase extraction (MSPE) and spectrofluorimetric determination of metoprolol in different biological samples. Biological sample was prepared and adjusted to pH 3-4, then metoprolol was quickly extracted using iron oxide magnetic nanoparticles (IOMNPs) modified by the surfactant sodium dodecylsufate (SDS) and determined applying spectrofluorimetry. Experimental conditions, such as the amount of NPs and SDS, 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’s concentration range of 5-100 ng mL-1 with correlation coefficients (r2) of 0.999. The method showed good precision and accuracy, with intra– and inter–assay precisions of less than 6% at all concentrations. Standard addition recovery tests were carried out, and the recoveries ranged from 86% to 107%. The limits of detection was found to be 2.3 to 5.3 ng mL-1. The method was applied to the determination of metoprolol in different biological samples.