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Introduction: The possibility of resveratrol electrochemical determination, assisted by cobalt (III) oxyhydroxide and its composites with conducting polymers has been evaluated from the theoretical point of view. Methodology: The correspondent mathematical model has been developed and analyzed by means of the linear stability theory and bifurcation analysis. Results: The analysis of the model confirms that the cobalto oxyhydroxide may serve as an efficient electrode modifier for resveratrol electroanalytical determination. Conclusion: Depending on the analysis conditions, the electroanalytical process may be either diffusion- or kinetically controlled. On the other hand, the oscillatory behavior is also possible being even more probable than in the simplest cases, due to the impact of the chemical and electrochemical stages on DEL. [ABSTRACT FROM AUTHOR]

Introduction: For the first time, the possibility of anodic electroanalytical detection of ledol -- the main toxin in the nectars and honeys of some toxic flowers -- by the electrode, modified by the conductive polymer composite with cobalt oxyhydroxide is evaluated. Methodology: The electrooxidation of ledol will be realized via cyclopropane ring, followed by the oxidation of the secondary alcoholic group to ketone. Results and discussion: Analysis of the corresponding model using linear stability theory and bifurcation analysis confirms that cobalt oxyhydroxide in composite with conductive polymer can serve as an effective anode modifier for determining ledol in honeys, nectars and other sources natural. As ledol is poorly ionized, the oscillatory behavior will only be caused by the effects of the electrochemical stage in the double electric layer (DEL). Conclusions: Cobalt oxyhydroxide can be used for detection of ledol for safety verification of honeys. [ABSTRACT FROM AUTHOR]

Introduction: methaqualone is a calming drug, generally used to replace barbiturates, since it does not have side effects, which they cause, causing, however, their own - and quite significant ones. Its performance strongly depends on the applied dose, which is why the measurement of its concentration is current. Methodology: for the first time, the behavior of the system with the electroanalytical determination of methaqualone in basic medium on the electrode, modified by the composite of poly(5-amino-1,4-naphthoquinone) with cobalt oxyhydroxide, has been theoretically described. The corresponding mathematical model was developed and analyzed using linear stability theory and bifurcation analysis. Results: as the ionic function of the reaction product is opposed to the ionic function of the reactant, the oscillatory behavior will increase its probability of realization, given the sudden changes in the structure and ionic strength of the electrical double layer (ECD). Nevertheless, the poly(5-amino-1,4-naphthoquinone)/CoO(OH) composite is an efficient modifier for methaqualone detection, which can be shown with the model. Conclusion: the poly(5-amino-1,4-naphthoquinone)/CoO(OH) composite can be an effective modifier for the electrochemical detection of methaqualone in basic medium. [ABSTRACT FROM AUTHOR]

Introduction:olanzapine is one of the most used antipsychotic drugs in the world. Although it is efficient, it may be toxic in excess. Therefore, in this work the possibility of olanzapine electrochemical determination over an electrode, modified by the cobalt (III) oxyhydroxide in pair with its dioxide in a composite with squaraine dye. Methods: the trivariant correspondent mathematical model includes two scenarios of the drug oxidation, possible for the case, including the indirect electropolymerization of the condensed benzodiazepine molecule, like also its oxidation by sulfur atom. This model has been developed and analyzed by means of stability theory and bifurcation analysis. Results and discussion: the analysis of the model has shown that the mechanism hybridity of the electroanalytical process, alongside with the formation and decomposition of ionic compounds during its realization, augments the possibility for the oscillatory behavior realization, relatively to the simplest and commonest case. Nevertheless, the oscillatory instability is realized in parameter values far beyond the detection limit. On the other hand, the stable steady-state is easy to obtain and maintain, indicating an efficient electroanalytical process, controlled by the analyte diffusion. Conclusions: the electroanalytical process is efficient. The cobalt compound is acting as an active substance, and the dye is the mediator. [ABSTRACT FROM AUTHOR]

The possibility of tramadol in vivo and in vitro electrochemical determination by means of the sensor, based on cobalt (III) oxyhydroxide and its composite with conducting polymers was evaluated from the mechanistic point of view. The mathematical model, correspondent to the suggested mechanism, was developed and analyzed by means of linear stability theory and bifurcation analysis. It was shown that CoO(OH) may be applied to the tramadol electrochemical determination in neutral and lightly alkaline pH values, correspondent to the more efficient oxidation of the compound. The possibility of oscillatory and monotonic instabilities has also been modified. [ABSTRACT FROM AUTHOR]