Effect of carbon nanohorns in the radical polymerization of methacrylate monolithic capillary columns and their application as extractant phases.

A successful copolymerization of the single-walled carbon nanohorns (SWNHs) with methacrylate monomers was achieved via thermal initiated free-radical polymerization because of the high reactivity of the SWNHs in comparison with other carbon nanostructures. The hybrid solids were deeply characterized in terms of morphology, by scanning electron microscopy (SEM). The effect of the incorporation of the bare or oxidized (o-SWNHs) carbon nanoparticles at different percentages (0-0.5 wt%) in polymerization mixtures to obtain hybrid monolithic capillary columns has been evaluated. In addition, their impact both in the polymerization step and in the extraction capacity was deeply studied. Final hybrid monoliths were applied for the extraction of polycyclic aromatic hydrocarbons and nonsteroidal anti-inflammatory drugs in water and biological samples, respectively. The precision was calculated both intra- and inter-capillaries obtaining satisfactory RSD values of less than 19.1%, which indicated the high robust reproducibility of the extraction procedure and the synthesis method. The accuracy of the method was also evaluated through a recovery study giving good recovery values, which varied between 78% and 112% for PAHs in waters, and 90-114% for NSAIDs in human urine samples.