Magnetic restricted-access microspheres for extraction of adrenaline, dopamine and noradrenaline from biological samples

Epoxy propyl bonded magnetic microspheres were prepared by atomic layer deposition using Fe3O4@SiO2 microspheres as a core support material. Then, a restricted-access magnetic sorbent was prepared that contains diol groups on the external surface and m-aminophenylboronic acid groups on the internal surface. This kind of microspheres achieved excellent specific adsorption of the ortho-dihydroxy compounds (dopamine, adrenaline and noradrenaline). Following desorption with sorbitol, the ortho-dihydroxy compounds were quantified by HPLC. The limits of detection for dopamine, adrenaline and noradrenaline were 0.074, 0.053 and 0.095 mu g mL(-1), respectively. Recoveries from spiked mice serum samples range from 80.2 to 89.1 %.