Effect of Tea Infusion Strength on Equivalent Circuit Parameters of Multielectrode Voltammetric Sensor System

Analysis of voltammetric response obtained from black tea liquor samples has been used extensively in research to evaluate tea quality. The recent system identification-based quality estimation method of black tea uses the equivalent circuit parameters of the voltammetric system. This work reports the analysis of these equivalent circuit parameters of a multielectrode voltammetric system in correlation with the change in concentration of black tea liquor. In this work, the experimental input–output data obtained using the voltammetric analysis of tea liquor is subjected to the system identification to obtain the system process model. The model hence obtained is subjected to a network synthesis procedure to estimate the equivalent circuit parameters of the system with various electrodes and at different concentrations of tea samples. Therefore, the tea infusion strength is simulated by varying concentrations. The performance parameters of the models identified for all the electrode–analyte combinations are calculated by comparing the experimental and the simulated waveforms. The study of the concentration of tea samples and circuit parameters agrees with the theoretical concepts. This work therefore also provides a legitimate validation to the established equivalent circuit for the voltammetric taste measurement system (electronic tongue). The cluster analysis performed here reveals a potential application of this work in the domain of electronic tongue.