Commercially available pesticides were examined as Mus musculus and Homo sapiens acetylcholinesterase (mAChE and hAChE) inhibitors by means of ligand-based (LB) and structure-based (SB) in silico approaches. Initially, the crystal structures of simazine, monocrotophos, dimethoate, and acetamiprid were reproduced using various force fields. Subsequently, LB alignment rules were assessed and applied to determine the inter synaptic conformations of atrazine, propazine, carbofuran, carbaryl, tebufenozide, imidacloprid, diuron, monuron, and linuron. Afterwards, molecular docking and dynamics SB studies were performed on either mAChE or hAChE, to predict the listed pesticides’ binding modes. Calculated energies of global minima (E_{glob_min}) and free energies of binding (∆G_binding) were correlated with the pesticides’ acute toxicities (i.e., the LD₅₀ values) against mice, as well to generate the model that could predict the LD₅₀s against humans. Although for most of the pesticides the low E_{glob_min} correlates with the high acute toxicity, it is the ∆G_binding that conditions the LD₅₀ values for all the evaluated pesticides. Derived pLD₅₀ = f(∆G_binding) mAChE model may predict the pLD₅₀ against hAChE, too. The hAChE inhibition by atrazine, propazine, and simazine (the most toxic pesticides) was elucidated by SB quantum mechanics (QM) DFT mechanistic and concentration-dependent kinetic studies, enriching the knowledge for design of less toxic pesticides.

An efficient, highly sensitive, fast and selective kinetic method for determination of traces of Cu(II) was developed and applied for its quantification in different real samples. The method was based on the catalytic effect of Cu(II) traces on the redox reaction of artificial azo-dye tartrazine (tri-sodium-5-hydroxy-1-(4-sulfophenyl)-4-[(4-sulfophenyl)azo]pyrazole-3-carboxylate) with H₂O₂. The optimum operating conditions regarding reagent concentration were examined and established. Linearity of the method was obtained in the concentration range from 13 to 318 ng/mL of Cu(II), with a detection limit (LOD) (3s _b/m) of 2 ng/mL, and limit of quantification (LOQ) (10s _b/m) of 7 ng/mL. Obtained results for Cu(II) determination in analyzed samples, as well as the development and validation of the proposed analytical procedure are given and discussed.

Development and application of a simple, fast, green analytical kinetic method for the determination of micro-amounts of gold(III ) ions, were presented in this paper. The method was based on the inhibitory effect of traces of Au(III) ions on the redox reaction between disodium-6- hydroxy-5-[(4-sulfophenyl)azo]-2-naphtalenesulfonate (artificial azo-dye 'Sunset Yellow FCF', E110 in further text selected as SY ) and hydrogen- peroxide, in alkaline media of borate buffer. All experimental parameters affecting to the determination: reagent concentrations, pH and temperature were investigated and optimised. Working experimental conditions are set according to the highest sensitivity of the proposed kinetic method for the determination of Au(III) ions. The linearity of the method was obtained within the range 1.97-59.07 μg/mL of Au(III) ions with relative standard deviation of 3.66-0.43 %, respectively. The influence by possible interference effects by major ions on the determination of Au(III) and their limits are investigated, at the constant Au(III) concentration of 39.39 μg/mL. The results of Au(III) determination in samples obtained by proposed kinetic method and comparative ICP-OES method were statistically agreeable. Obtained results for Au(III) determination in analyzed samples, as well as the development and validation of the proposed analytical procedure have given and discussed