| The research presented herein describes the development and optimization of a reversed-phase high-performance liquid chromatography technique coupled with electrochemical detection (RP-HPLC-EC) for the analysis of catecholamines. The method relies on the beneficial electrochemical properties of a novel electrode material, boron-doped diamond. Detection of norepinephrine (NE), epinephrine (EP), dopamine (DA), 3,4-dihydroxyphenylethylene glycol (DOPEG), vanillic mandelic acid (VMA), normetanephrine (NM) and metanephrine (MN) was successfully performed with limits of detection (LOQ, S/N = 3) ranging from 245 pg to 3 ng. The method was applied to the quantitation of NE in rat tissues using a solid-phase extraction (SPE) technique for sample clean-up. The electrode response exhibited no signs of fouling after 80 days (RSD = 6.7%), 100's of injections of tissue samples and required no rigorous pretreatment. The mechanism of catecholamine redox chemistry at diamond was also studied by cyclic voltammetry as a function of potential sweep rate and solution pH. |
