Four-dimensional voltammetry: An efficient strategy for simultaneous determination of ascorbic acid and uric acid in the presence of dopamine as uncalibrated interference

Abstract

In this work, we have developed a novel electroanalytical methodology based on generation of third-order differential pulse voltammetric (DPV) data for simultaneous determination of ascorbic acid (AA) and uric acid (UA) in the presence of dopamine (DPA) as uncalibrated interference. To generate third-order DPV data, two instrumental parameters including pulse height and pulse time were changed. Each sample had a three-way data array containing six matrices recorded at six different pulse times and each matrix had six vectors recorded at six different pulse heights. By joining three-way data arrays, we could generate a four-way data array. After data pre-processing, a calibration model was built by augmented parallel factor analysis (APARAFAC) and multivariate curve resolution-alternating least squares (MCR-ALS) and their performance for simultaneous determination of AA and UA in the absence and presence of DPA as uncalibrated interference was examined by predicting concentrations of validation and test set, respectively. Our records confirmed successfulness of MCR-ALS in predicting concentrations of AA and UA in both validation and test sets and then, it was applied to the analysis of real samples. Fortunately, the results of MCR-ALS in analyzing real samples were acceptable which also confirmed development of a novel method.