Graphene nanoparticles as pseudostationary phase for the electrokinetic separation of nonsteroidal anti‐inflammatory drugs

The exceptional properties of graphene (G) were exploited here to facilitate capillary electrokinetic separations. Two types of commercially available G consisting of nanoparticles containing—one to three and—four to six G sheets, respectively, were compared for this purpose. Both proved effective in separating the arylpropyl derivatives of nonsteroidal anti‐inflammatory drugs. The highest resolution and shortest migration times were obtained with G containing high amount of single and double G nanosheets. G affords higher resolution than other types of nanoparticles; stable suspensions can be easily prepared and used as BGE without the need of adding an additional surfactant. This results in a high reproducibility in migration times and stability in background noise. The LOD and LOQ obtained by using G nanoparticles as pseudostationary phases spanned the range 0.29–1.18 mg/L and 0.95–3.95 mg/L, respectively, and the RSD was less than 4.7% in all instances.