Optimization of magnetic extraction by experimental design methodology for the determination of antidepressants in biological samples
In this study, a novel and sensitive magnetic solid phase extraction (MSPE) method based on Fe3O4–MgSiO3 magnetic nanocomposites was developed for extraction and preconcentration of venlafaxine, escitalopram, paroxetine, sertraline and fluoxetine in biological samples followed by liquid chromatography-ultraviolet detection (LC-UV). The effects of some factors influencing the extraction efficiency of antidepressants including adsorbent amount, extraction pH, and desorption solvent volume were optimized using experimental design methodology. The optimum conditions were found to be adsorbent amount: 12.5 mg, extraction pH: 7.4 and desorption solvent volume: 1.3 mL. Under the optimum experimental conditions, a good linearity was observed for all analytes, with the square of correlation coefficients (R2) ranging from 0.9986 to 0.9994. The limit of detection and limit of quantification for the antidepressant drugs were found to be in the range of 1.73–2.83 and 5.21–8.53 ng mL−1, respectively. This method was successfully applied to analyze real biological samples at different spiked concentrations, and the obtained recoveries ranged from 72 to 115% with relative standard deviations (RSDs) below 4.75%.