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Chronic indirect Pb exposure results in lipid peroxidation in erythrocytes of apprentices via OS, and duration of Pb exposure is a reliable marker of Pb toxicity.

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Poly(2-fluroaniline) and poly(2-chloroaniline) were synthesized by an electrochemical method in an acetonitrile solution containing tetrabutylammonium perchlorate and perchloric acid. Also, the electrochemical copolymerization of aniline with 2-fluroaniline and 2-chloroaniline was carried out in the same medium. Cyclic voltammograms of the deposited films were recorded in neutral, acidic, and basic solutions. The electrochemical behavior of the films showed the same characteristic results as conventional polyaniline. The observed decrease in the dry electrical conductivity of the copolymers with respect to polyaniline was attributed to the incorporation of the fluoro-and chloro-substituted anilines into the polyaniline chain. Further characterization of the polymer and copolymer products was performed through dry electrical conductivity measurements, ultraviolet-visible spectroscopy, and Fourier transform infrared spectroscopy. The relative solubility of the films was determined in various common organic solvents.

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Electrochemical preparation of poly(2-bromoaniline) (PBrANI) and poly(aniline-co-2-bromoaniline) [P(An-co-2-BrAn)] was carried out in an acetonitrile solution containing tetrabutylammonium perchlorate (TBAP) and perchloric acid (HClO 4 ). The cyclic voltammograms during the copolymerization had many features similar to those for the usual polymerization of aniline. The copolymer exhibits a higher dry electrical conductivity value than that of PBrANI and a lower one than that of PANI. The observed decrease in the conductivity of the copolymer relative to PANI is attributed to the incorporation of bromine moieties into the polyaniline chain. The structure and properties of the polymer and copolymer were elucidated using cyclic voltammetry (CV), FTIR, and UV-vis spectroscopy.

In the present work, 11 aromatic and nine aliphatic carboxylic acids, namely benzoic, 2-nitrobenzoic, 3-nitrobenzoic, 4-nitrobenzoic, 2,4-dinitrobenzoic, 3,5-dinitrobenzoic, 2-aminobenzoic, 3-aminobenzoic, 4-aminobenzoic, o-phthalic, salicylic, formic, acetic, monochloroacetic, dichloroacetic, trichloroacetic, propionic, n-butyric, caprylic, and myristic acids, were titrated conductimetrically and potentiometrically with triethylamine in acetonitrile solvent, under a nitrogen atmosphere, at 25 °C. Closer investigation of the conductimetric titration curves of these acids showed that the acidity of an acid, rather than the basicity of its conjugate base, plays a major part in the formation of homoconjugate ions, at least in acetonitrile solvent. If the acid is strong enough, there is a maximum before the experimental end point at about the half-neutralization point. To determine the minimum strength for an acid to show this maximum before the end point, all acids were also titrated potentiometrically. It was found that those acids which have half-neutralization potentials over −85 mV give a strong homoconjugation reaction and show a maximum before the experimental end point. Moreover, the acids that show maxima before the experimental end point in the conductimetric titration also show rather well-shaped potentiometric titration curves. Keywords: nonaqueous media, conductimetric titrations, potentiometric titrations, titration in acetonitrile, acidity and homoconjugation.