Selective DPV method of dopamine determination in biological samples containing ascorbic acid

摘要

A modified carbon paste electrode that incorporates the anionic surfactant sodium dodecyl sulfate (SDS) in the paste (SDS-CP) is reported. It is shown that the SDS-CP electrode discriminates effectively between the cationic form of dopamine and the anionic electroactive species existing in biological fluids at the physiological pH. Therefore, a differential pulse voltammetry method has been developed. It has the detection limit comprised in the submicromolar range and the capability to remove the interference of the ascorbic acid and to diminish the interference of the uric acid. The method has been tested with good results on real samples of deproteinized serum.