Magnetic N-doped mesoporous carbon as an adsorbent for the magnetic solid-phase extraction of phthalate esters from soft drinks

A new kind of magnetic N-doped mesoporous carbon was prepared by the one-step carbonization of a hybrid precursor (glucose, melamine, and iron chloride) in a N-2 atmosphere with a eutectic salt (KCl/ZnCl2) as the porogen. The obtained magnetic N-doped mesoporous carbon showed excellent characteristics, such as strong magnetic response, high surface area, large pore volume, and abundant p-electron system, which endow it with a great potential as a magnetic solid-phase extraction adsorbent. To evaluate its adsorption performance, the magnetic N-doped mesoporous carbon was used for the extraction of three phthalate esters from soft drink samples followed by high-performance liquid chromatographic analysis. Under the optimum conditions, the developed method showed a good linearity (1.0-120.0 ng/mL), low limit of detection (0.1-0.3 ng/mL, S/N = 3), and good recoveries (83.2-119.0%) in soft drink samples. The results indicated that the magnetic N-doped mesoporous carbon has an excellent adsorption capacity for phthalate esters and the present method is simple, accurate, and highly efficient for the extraction and determination of phthalate esters in complex matrix samples.