Simultaneous determination of ascorbic and uric acids and dopamine in human serum samples using three-way calibration with data from square wave voltammetry

We present for the first time a novel analytical method based on a model of three-way calibration using second order data generated from the combination of records of forward (oxidation) and reverse (reduction) currents using a glassy carbon electrode modified with a dispersion of electrochemically reduced graphene oxide (GCE/RGO) as the working electrode, which can be obtained from a square wave voltammetry single experiment. This methodology was used for the simultaneous determination of ascorbic (AA) and uric (UA) adds, and dopamine (DO) in the presence de glucose (interfering species) in lyophilized human serum samples. The serum samples have analyte different concentration levels (normal and pathological levels). The forward and reverse currents were pre-processed using AsLS and COW, to generate the second order data and finally the data were modeled with the U-PLS algorithm. Recovery studies were made in order to validate the proposed method. Recovery percentages between 92.4 and 120% were obtained. The present method has the advantage to generate second order data through a simple voltammetric experiment. Among the advantages of the proposed method can be mentioned speed, easy data acquisition and the possibility of using modified electrodes with nano-structures. (C) 2016 Elsevier B.V. All rights reserved.