mbarki mohamed

During this work, we studied the reactivity of 4-isothiazolin-3-one and 2-methyl-4-isothiazolin-3-one with Dibromine and with Sulfuryl Chloride by the DFT method at the level of base 6-311 G(d,p), using a descriptor of regio-selectivity called fukui indices. We noted from this study that the attack of Dibromine and Sulfuryl Chloride is carried out preferentially at the level of the C2=C3 bond of 4-isothiazoline-3-one and 2-methyl-4-isothiazoline-3-one. We also noticed that the 4-isothiazolin-3-one/SO2Cl2 and 2-methyl-4-isothiazolin-3-one/SO2Cl2 reactions are more favored kinetically than the 4-isothiazolin-3-one/Br2 and 2-methyl- 4-isothiazolin-3-one/Br2. The differences in electrophilic Δω between {Br2, SO2Cl2} and 4-isothiazolin-3-one and also between {Br2, SO2Cl2} and 2-methyl-4-isothiazolin-3-one vary from 3.430649 eV to 3.611297 eV. This shows that all the reactions studied have a polar character (Δω >1).

Cyclic voltammetry and differential pulse voltammetry techniques for the simultaneous analysis of ibuprofen (IBU) and paracetamol (PCT) at carbon paste electrode modified with clay (CPE-Clay) are reported. The surface characterization of the clay was realized by zero-point charge and electrochemical methods. The electrocatalytic activity of clay toward ibuprofen electro-oxidation and paracetamol redox were reported. The kinetic parameters for ibuprofen and paracetamol electro-analysis by the modified carbon paste electrode clay-CPE were calculated. Peak ibuprofen oxidation and peaks paracetamol redox were well presented onto modified electrode clay-CPE when compared with other electrodes in the literature.  Peak oxidation of the ibuprofen and peaks paracetamol redox was well presented onto modified electrode clay-CPE compared with other electrodes in the literature. The high sensitivity of the clay-CPE is measured by the DPV method showed linear variation with ibuprofen and paracetamol concentration with respectively detection limit (LOD) of 3.23×10-8 mol L-1 and 1.04×10-8 mol L-1. The applicability of the working electrode has been explored by the simultaneous electroanalysis of the ibuprofen and paracetamol in human blood samples.

In this work, we investigated the applicability of the clay-modified carbon paste electrode (CPE-clay) in the detection of paracetamol (PAR), using two electrochemical methods differential pulse voltammetry (DPV) and cyclic voltammetry (CV) in the range between 20 and 400 mV in a Britton Robinson buffer solution (pH 7). The voltammetric technical behavior of PAR is studied where a sensitive anodic and cathodic peak has been appeared at about 0.4 V and 0.2 V (vs. Ag/AgCl/3 M KCl) successively. These peaks were recorded from the reversible redox of PAR at the CPE-clay surface. The proposed technical (DPV, CV) exhibits remarkably an electro-catalytic success for PAR redox. The current response of the catalytic peaks obtained by DPV depended linearly on the concentration of PAR in the range between 1.0 × 10-6 and 1.0 × 10-3 mol L-1 with a detection limit of 5.27 × 10-9 mol L-1. Subsequently, the relative standard deviation (RSD) at 1.0 × 10-4 mol L-1 PAR concentration was 3.8% for nine replicates. The proposed electrode has been successfully used for PAR detection in the human blood sample.