The separation and preconcentration of copper(II), lead(II), and cadmium(II) ions on magnetic graphene oxide (MGO) by solid-phase extraction was carried out. Quantitative recovery was obtained by adsorption of analytes on MGO at pH 6 and elution of 3 M HNO3 in 10% acetone. To optimize the presented method, the effects of various parameters-including pH, eluent conditions, and vortex time-were examined. Matrix effects were also investigated. Mean recoveries of the analytes were between 95 and 105%. The proposed method was validated by applying it to certified reference materials. Addition and recovery tests were also performed. The method was applied to verify the analyte content of several water and food samples.