Multifrequency large amplitude pulse voltammetry: A novel electrochemical method for electronic tongue

A novel electrochemical method, multifrequency large amplitude pulse voltammetry (MLAPV) for electronic tongue was introduced in this paper. It was constructed by several large amplitude pulse voltammetry (LAPV) with deferent step length. The applied waveform of MLAPV comprises three individual frequency segments, 1 Hz, 10 Hz and 100 Hz. The electronic tongue based on MLAPV was constructed by several metallic working electrodes, such as platinum, gold, titanium, nickel, palladium, a Ag/AgCl reference electrode and a pillar platinum electrode as counter electrode for standard three-electrode systems. Principal component analysis (PCA), a kind of multivariate data analysis (MVDA) was used for processing the data from the electronic tongue. In the present study, six Chinese distilled spirits and seven Longjing teas were analyzed by the electronic tongue based on MLAPV and were successfully discriminated by the working electrodes at different frequency segments. The results showed that frequency segments on the working electrode played a key role in discriminating various samples. MLAPV made the same metallic working electrodes have different separation ability at each segments. Better discrimination ability can be achieved by the combination of working electrodes with specific frequency segments. The present work showed that MLAPV is a useful method to reveal the specific frequency segment for each working electrode in various analysis systems.