Study of the BHT Oxidation Mechanism Coupling Theory and Experiment.

In the present work, the oxidation mechanism of di--butyl-hydroxytoluene (BHT) was studied in an aqueous medium through different approaches to have a thorough vision of the physical chemistry: experiments with cyclic voltammetry (CV), quantum chemical calculations, and simulations of CV. Calculations of thermodynamic parameters, such as p and standard oxidation potential ( °), were used to analyze and rationalize the CV experiments. Subsequently, different pathways of the mechanism were constructed, and the most thermodynamically favorable one was selected.

Multivariate Optimization of Electrochemical Biosensors for the Determination of Compounds Related to Food Safety-A Review.

We summarize the application of multivariate optimization for the construction of electrochemical biosensors. The introduction provides an overview of electrochemical biosensing, which is classified into catalytic-based and affinity-based biosensors, and discusses the most recent published works in each category. We then explore the relevance of electrochemical biosensors for food safety analysis, taking into account analytes of different natures.

Development of a voltammetric electronic tongue for the simultaneous determination of synthetic antioxidants in edible olive oils.

A voltammetric electronic tongue (E-tongue) is "a multisensor system, which consists of a number of low-selective sensors and uses advanced mathematical procedures for signal processing based on pattern recognition and/or data multivariate analysis such as artificial neural networks (ANNs), principal component analysis (PCA), among others". Thus, E-tongues in combination with chemometrics tools result in more accurate and selective analytical methods. In this work, we report results of a simple and reliable electroanalytical method to determine butyl hydroxyanisole (BHA), butyl hydroxytoluene (BHT) and propyl gallate (PG) in edible olive oils (EOO).

Second-order electrochemical data generation to quantify carvacrol in oregano essential oils.

A novel analytical method using voltammetric second-order modeling based on multivariate curve resolution-alternating least-square (MCR-ALS) is presented for the first time for the quantitation of carvacrol (CAR) in oregano essential oils (OEO). The second-order cyclic voltammetry data were generated on the basis that CAR shows a diffusional system. Thus, the scan rate (v) was used as a second instrumental mode and cyclic voltammograms at different v were acquired for a single sample, generating the second-order data.

Development of an electrochemical method to determine phenolic monoterpenes in essential oils.

A simple, rapid and non-expensive method is proposed to determine phenolic monoterpenes such as thymol and carvacrol in essential oils of thyme and oregano. The linear sweep voltammetry based on glassy carbon electrodes was the electrochemical technique used. Thymol and carvacrol have one main oxidation peak in non-aqueous media centered at about 1.

A porphyrin-based fluorescence method for zinc determination in commercial propolis extracts without sample pretreatment.

The quantification of zinc in over-the-counter drugs as commercial propolis extracts by molecular fluorescence technique using meso-tetrakis(4-carboxyphenyl)porphyrin (H TCPP ) was developed for the first time. The calibration curve is linear from 6.60 to 100 nmol L of Zn .