Multicomponent Titration of Calcium + Magnesium Mixtures Employing a Potentiometric Electronic‐Tongue

Abstract

A fast novel potentiometric titration procedure is proposed, in which the detection system is formed by a potentiometric electronic tongue. The titration consists in a reduced number of fixed titrant additions to the sample and the recording of the potentials of an array of Ion Selective Electrodes. The obtained data matrix is entered to an Artificial Neural Network response model, previously trained to furnish concentrations of a multicomponent mixture. The principle is demonstrated with automated EDTA titration of mixtures of Ca 2þ and Mg 2þ at fixed pH 8.5. In this case, five 2 ml fixed volume additions plus the readings of four sensors were adequate for the resolution of the mixture. In the conditions used, titration was feasible up to 3.3 mM total ion concentration, the precision was estimated as 3.20% RSD for Ca 2þ and 2.76% RSD for Mg 2þ (n ¼ 5), and the detection limits 0.16 mM Ca 2þ and 0.26 mM Mg 2þ . The procedure was applied to mineral waters and compared with reference methods (correlation ¼ 0.92 for Ca 2þ and correlation ¼ 0.89 for Mg 2þ , n ¼ 14).

A Simultaneous Determination Method for the Analysis of Chloride and Nitrate Ions in Air Samples by PLS1

“…Electronic tongues benefit the cross sensitivities of different ion-selective electrodes involving a sensor array and evaluate the results by a chemometric database. Although the use of multi-ISE arrays and chemometrics for the qualitative and quantitative analysis of different cations have been reported frequently (18)(19)(20)(21)(22)(23)(24)(25), there are limited studies about the anion analyses by using the multi-ISE arrays (26)(27)(28)(29)(30)(31). Some of these reported studies are only for anion analysis, while others are based on the analysis of both anions and cations.…”

Electronic Tongues Employing Electrochemical Sensors

“…The initial proposal described a fast titration procedure consisting in a reduced number of fixed titrant additions to the sample and the recording of the potentials of an array of ISEs (Figure 11). The obtained data matrix was then entered to an ANN model, previously trained to furnish concentrations of a two-component mixture of Ca 2þ and Mg 2þ [130]. The proposal opened a procedural methodology for multideterminations, in which the old masking chemistry may be replaced by the electronic tongue approach, and where a very simple analytical procedure, the titration, would yield multicomponent information.…”

Recent trends in potentiometric sensor arrays—A review

“…For example, the use of titration in conjunction with the data processing using neural networks was used in Refs. [65,66] to determine the alkalineearth components (Ca 2+ , Mg 2+ and Sr 2+ ).…”