Study On The Mathematical Analysis And Application Of Charging Current Impulse Response Signal Based On Voltammetric Electric Tongue

Unlike conventional electro-analytical chemistry, that charging current is often used as interference signal in a oxidox or redox currents to shield, it is considered as effective signal to be acquired and applied, whose validity is an important element of application capacity in voltammetric electronic tongue. This study is based on multifrequency large amplitude pulse voltammetric electronic tongue (Smartongue) developed by our group, aiming at hoping electronic tongue have a higher distinction capacity in whole quality characteristics of the sample using analytical parameters based on mathematical principles,then we research through the following several aspects:(1) Getting charging current and choosing best mathematical inversion algorithmFor problem that mixing faraday current signal in vertex causes the ability to distinguish limited, we get pure charging current in potassium ferrocyanide with different concentrations, which mixed with same concentrations of potassium nitrate, different concentrations one, without one, using that voltage is 3mv, excitation time is 50ms. From comparing quantitative analysis results, which contains the correlation analysis of the maximum of charging current and concentration, charge and concentration, the results which is R2>0.9, p<<0.05 (whenc α=0.05), show that method of equivalent circuit design can acquire pure charging current effectively. For the mathematical analysis of charging current, New SVD chosen as the best inversion algorithm from comparing SIRT, SVD-SIRT and New SVD.(2) The application of analytical parameters of charging currentFor problem that analysis results of charging current is too simple, paper study on the charging current analytical parameters from the ion movement, which characterizes through the inversion results in the characterization of a range of relaxation on the abscissa, and the correlation between conductivity and concentration area, based on G=k1*c-k2*c2/8+ε which derived from theory of electrical conductivity and concentration c. The results, from substances of two types which contain the single and the mixtures, of ions movement that is alike to the theoretical one which is the mixture of sodium sulfite and citric> the mixture of sulfate and tartrate> sulfate ion> citrate ions> tartrate ion, and the correlation that is R2>0.9, p<<0.05 (when α=0.05), show that charging current of analytical parameters not only can be used to evaluate the ions movement distinction of different solutions, but also can extract the correlation between electrical conductivity and concentration parameter to do applied research.(3) The verification on application of analytical parameters of charging currentWe study on the relationship, between analytical parameters and ion movement,and comparison of discrimination ability, between inversion analysis parameters and vertex characteristic value in food samples using PCA and DI via food samples, including the different type:mixed fruit and vegetable, oil and water mixture, milk; the different brands of the same type:yili pure milk, bright milk, Meng Niu milk. By analyzing inversion analysis results, we predict the ion movement of food samples as follows: bright milk> oil-water mixture> mixed fruit and vegetable> yili pure milk> mengniu milk. Based on good correlation between conductivity and concentration, which is R2>0.9, p<<0.05 (when α =0.05), characteristic value we extract fitting coefficients as and the vertex in smartongue both can distinguish food samples, but the DI values of former is higher, which is 99.0306, and the latter is 91.6608 in different types, and which is 82.8982, and the latter is 71.07 in same types. It show that analytical parameters values have a higher distinguishing ability, to make up for shortcomings of the vertex mixed with the faraday currents.In summary, this paper identifies the equivalent circuit design method to obtain pure charging current, and through the new SVD algorithm to get parameters can be used in ion moving speed and the electrical conductivity, and the analytical parameters values have a high ability to distinguish, provided a conditions for research into pulse voltammetric electronic tongue.