Magnetic Solid-Phase Extraction in Combination with Ultra High-Performance Liquid Chromatography-Tandem Mass Spectrometry Analysis: Quantification of Risperidone and 9-Hydroxyrisperidone in Biological Samples

Oleic acid modified Fe3O4 nanoparticles were proposed for magnetic solid-phase extraction coupled with ultra high-performance liquid chromatography-tandem mass spectrometry to determine risperidone (RISP) and 9-hydroxyrisperidone (9OHR) in biological samples. The effects of various experimental parameters including adsorbent amount, pH, adsorption time, eluent type and concentration were systematically investigated. Under optimal conditions, the calibration curve was linear within the concentration range of 0.2-200 ng mL-1 with the correlation coefficient (r) of 0.9962 and the lower limit of q...