JBCS

The chemistry of ionic liquids is impressive. No doubt! In this article it is overviewed some contributions to the development of catalysis and catalysts in ionic liquids, especially those with imidazolium-based derivatives. Due to the importance of ionic liquids, some physicochemical properties of interest and their supramolecular organization are also described

Conductive N-substituted polyaniline was synthesized by incorporation of brominated polystyrenic chains onto emeraldine form of polyaniline. The obtained terpolymer was characterized using FTIR, DSC, TGA, UV-Vis and cyclic voltammetry

The kinetic model that describes the alkaline decomposition of potassium arsenojarosite in NaOH and Ca(OH)₂ media was obtained and verified

This figure shows TPR (temperature programmed reduction) profiles of fresh and regenerated K-promoted vanadium-alumina catalysts. The differences observed in these TPR patterns confirm that the deactivation of these catalysts may be related with irreversible structural changes in the vanadium oxide speciation

The important steps of dispersive liquid-liquid microextraction procedure for the determination of palladium(II) using 2,2'-furyldioxime. A new dispersive liquid-liquid microextraction system was developed for the determination of Pd(II) in catalytic converter, anode slime, road sediment and water samples. The compound 2,2'-furyldioxime as a complexing agent was firstly used in the determination of Pd(II) by flame atomic absorptin spectrometry using dispersive liquid-liquid microextraction procedure

The analytical data presented in this study demonstrate that there may be a high degree of similarity between the compositions of essential oils from male and female specimens of Baccharis species

Enatiomeric resolution of repaglinide achieved on Chiralpak IA column using n-hexane:ethanol:TFA (80:20:0.2, v/v/v)

Orange tree leaves and orange peels attacked by citrus canker were analyzed by HRMAS NMR and chemometrics. Changes in metabolic profile have highlighted biochemical responses

An efficient synthesis of five D-galactose-based multivalent neoglycoconjugates from peracetylated D-galactose is reported. Glycodendrimers were obtained in few steps using cheap reactants in 44-55% overall yields

Cyclic voltammograms of a glassy carbon electrode modified with oracet blue and multi-walled carbon nanotubes (OBMWCNT-GCE) in a 0.1 mol L^-1 phosphate buffer solution (pH 7.0) at scan rate 20 mV s^-1 in (a) the absence and (b) the presence of 0.50 mmol L^-1 hydroxylamine. (d), (e) and (f) as (b) for OBMGCE, MWCNT-GCE and activated GCE, respectively. (c) as (a) for OBMGCE

In order to characterize the chemical modifications that were introduced onto the surface of multi-walled carbon nanotubes, studies involving Fourier transform infrared spectroscopy, Raman spectroscopy, thermogravimetric analysis, X-ray photoelectron spectroscopy, transmission electron microscopy and electric force microscopy were performed

In a chloride-containing medium, aluminum ions form a variety of low and high molecular weight hydrolytic complexes with +1 and +2 charge at pH values lower than 6.0. The complexes may contain coordinated water molecules and chloride ions. The best correspondence between ²⁷Al nuclear magnetic resonance (NMR), potentiometric and mass spectral data is achieved at lower fragmentation voltage and with quadrupole detection

Silica gel with bonded phenyl active groups was used to separate the hydrophobic fraction of Ca, Fe, Mg and Zn in dark honeys. Fe was found to be associated with this fraction to the highest degree (7-43% of its total). A strong positive correlation was established between the concentration of Fe in the hydrophobic fraction and the optical density of dark honeys

Bader volumes obtained with contour density of 0.001 a.u. at 4-component Dirac-Fock level suggest that eka-francium fluoride (top molecule, E119 in pink color) should be less ionic than lighter alkaline fluoride homologue such as KF (K in green), in contrast to the common chemical belief based on periodic trends - it would be expected the most ionic bond possible. This result should be understood as a consequence of relativistic effects

Countercurrent chromatography (CCC) was employed as a useful, fast and economic alternative to conventional chromatography techniques for the purification of a synthetic pterocarpanquinone, LQB-118

A simple and efficient protocol has been developed for the synthesis of 1,2,3-triazole derivatives by catalyst-free 1,3-dipolar cycloaddition of nitroalkenes with sodium azide under mild conditions. The reaction's scope proved to be quite broad and 1,2,3-triazole derivatives were obtained in good yields

Filter paper strip is combined with screen-printed carbon electrodes (SPCE) to assemble a microfluidic device for detecting Pb(II) and Cd(II) in aqueous samples. The portable microfluidic devices are demonstrated for direct quantification of Pb(II) and Cd(II) in aqueous samples without pretreatment of contaminated samples

In this study, the electrochemical reduction mechanism of citrinin (CITH) mycotoxin in a non-aqueous reaction medium was investigated. (CITH)₂H₂ is the dimeric product obtained from the Michael-type nucleophilic addition reaction of CITH₂- carbanion with another CITH molecule

We used an Aethalometer^® to measure BC concentrations with 5 s time resolution in the exhaust of a 1995 Dodge RAM 2500 diesel pick-up truck, equipped with an oxidation catalyst, using a chassis dynamometer during the acceleration, deceleration, and cruise modes of the hot start of the MEC01 test cycle (version 7.0)

The activities of PtSnIr/C and PtSn/C E-tek electrocatalysts were evaluated in a direct ethanol fuel cell (DEFC) and similar performance was obtained using PtSnIr/C, with half content of platinum. In situ Fourier transform infrared (FTIR) analysis revealed acetic acid as main product generated from ethanol oxidation on PtSnIr/C

Liquid-liquid extraction with low temperature partitioning was proposed to determine the carbamates pesticides, aldicarb, carbofuran and carbaryl, in grape juice and chocolate milk beverages. The method was quick, cheap and may be easily implemented for routine analysis

The Figure shows efficiency of DLLME-SFO technique for the extraction of the copper ion with the oxine ligand and using different extraction (1-dodecanol, 1-undecanol) and disperser (methanol, ethanol, acetone, acetonitrile) solvents

Oncocalyxone A has been shown to be cytotoxic to human tumor cells and DNA reactive. Electrochemical-electron spin resonance revealed the stability of its semiquinone. Experiments with nucleobases and ssDNA (single-stranded DNA) proved the DNA interaction. Nuclear magnetic resonance (NMR) experiments with N-acetylcysteine evidenced its Michael acceptor nature

Sulfonated ordered mesoporous polymers were prepared by co-mixing p-formaldehyde, p-toluenesulfonic acid (p-TsOH), sulfuric acid and mesoporous silica (SBA-15 or MCM-48) as a template. The prepared materials were applied as catalyst in oleic acid esterification with methanol

Fluoride determination in single and multi-walled carbon nanotubes was performed by ion-selective electrode after pyrohydrolysis. It was possible to digest up to 1 g of sample and to achieve low LOD