JBCS

The solvatochromic probes 2-(N,N-Dimethylamino)-7-nitro-9H-fluorene and the commercially available β-carotene and 2-chloro-7-nitro-9H-fluorene can be conveniently employed for determining the properties of solvents and their mixtures.

Color plots of bio-oils obtained from pyrolysis of three pulp mill residues and analyzed with comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometric detection (GCxGC/TOFMS) unveil the complexity and potential of these materials for industrial use.

Ethanolamine and ethylene diamine debrominate 3-bromocamphor giving the corresponding camphanimines in good isolated yields. The yield of the obtained camphanimines strongly depends on solvent polarity and steric demand of the applied amine. The reaction mechanism was investigated by means of density functional theory (DFT) calculations.

Novel types of polymer-drug conjugates based on PSMA with pendant medicinal compounds were synthesized, characterized. Hydrolysis reactions were also studied, and then drug release kinetics and mechanisms were reported to introduce a controlled drug delivery system.

The biotransformation using baker's yeast (BY) from Fleischmann as catalyst in aqueous/organic solvent biphasic system was chemoselective and formed the saturated ketone. The concentration of BY and substrate, temperature, pH and V_aq/V_org, influenced the reduction, and DMSO was the best co-solvent.

AFM micrographs showed that the electrodeposited film has a porous microstructure and good roughness. X-ray photoelectron spectroscopy (XPS) superimposed spectra indicated that the coating deposited over time had a variable composition: nanocrystalline hydroxyapatite nucleated at the inner layer, and amorphous calcium phosphate was formed at the outer layer.

Flowchart of the analysis of metal contents in samples of honey from bees from Amazonia (Brazil) and dendrogram with separation of the three types of honeys studied.

The major reaction of OH^- with 1,2-dichloro-4,5-dinitrobenzene in H₂O-DMSO involves the displacement of the nitro group, and transient Meisenheimer complexes are detected. Free radicals are detected in solvents of low water content, but not under the kinetic conditions.

The purpose of this study was to implement an analytical method that permits the determination of the presence of nonsteroidal anti-inflammatory drugs (NSAIDs) in water. Compound extraction was performed by solid-phase extraction (SPE) using an Oasis HLB cartridge. Analytes were analyzed by a simple method using HPLC-DAD.

Two new acyclic diterpenes, as well as the pyrrolizidine alkaloids florosenine and floridanine, among other known compounds, were isolated from Villasenoria orcuttii. The absolute stereochemistry of floridanine was determined by X-ray analysis and its NMR data were corrected.

Scheme of the procedure employed for the selective preconcentration of Cu(II) with polyurethane foam and eriochrome black T as ligand, aiming its determination in waters by flame atomic absorption spectrometry.

A set of SAPO-11 zeolites was synthesized by a hydrothermal method using different templates (diethylamine (DEA), di-n-propylamine (DPA) and di isopropylamine (DIPA)) and varying DPA content (nDPA/Al₂O₃ = 0.8, 1.2, 1.6 and 2.0). SAPO-11(DPA,1.2) exhibited the highest catalytic performance in the methylation of naphthalene with methanol.

This work shows the results obtained in the validation and characterization of a method for the analysis of pesticide residues in soil by modern analytical techniques. Ultrafast liquid chromatography coupled to mass spectrometry was used, and statistical analysis was performed according to international standards in order to ensure the reliability of the results.

A simple chemical derivatization of rifampicin and isoniazid modifies the spectral behavior of these drugs and allows their simultaneous determination using visible spectrophotometry by applying multivariate calibration (PLS).

Boron-doped diamond electrode surfaces can act as partially blocked or with heterogeneous electroactivity, depending on the polarization, that is, anodic or cathodic, respectively. This was demonstrated using the ferro/ferri-cyanide redox couple at very low scan rates.