JBCS

Carbonyl compounds are widely found in food products such as fried food. A derivatizing agent (2,4-dinitrophenylhydrazine) in conjunction with a chromatographic mass spectrometry system is the usual method to assess carbonyl compounds in foods and beverages.

Estuarine hydrodynamics under semiarid climate and the effects on Hg export to the sea in the Jaguaribe Estuary, NE Brazil.

A computational search (DFT) for the most stable structure of Pt(II)-PZA complex was performed associated to a mixed-level factorial design (5x3). Such statistical scheme allowed us to optimize system stability and interaction effects, among others.

An eco-friendly hydrocyanation method for sulfonylimines using non-toxic, nonvolatile and inexpensive potassium hexacyanoferrate(II) as an original cyanide source has been developed.

Experimental design-computer interactive simulation of an electropherogram is developed. The colored lines are calculated using response surface models. The corresponding experimental electropherogram is below.

A variety of heterocyclic systems was obtained from ring transformation of chromone-3-carboxamide under nucleophilic conditions.

This work aimed at comparing the performance of acid and base-catalyzed soybean oil methylation methods used for FA analysis. For this comparison, gas chromatography (GC) and easy ambient sonic spray ionization (EASI-MS) were used for chemical monitoring.

The supramolecular tetraruthenated porphyrins, {Mn-TPyP(H₂O)₂[RuCl₃(dppb)]₄}PF₆, was immobilized on a glassy carbon electrode by electropolymerization and used as a sensor for acetaminophen.

Quantum chemical descriptors for QSAR models of reaction rate constants k_O3 and k_OH of alkenes with ozone and OH radical were obtained from ground-state and transition-state structures of degradation processes. The present work tests that transition states have important effects on k_O3 and k_OH of degradation processes. Our models overcome the defect of literature models that only used the ground-state descriptors to build QSAR models for k_O3 and k_OH.

In the present work was evaluated the complexation capacity and conditional stability constant of organic matter from typical agricultural areas and from urban areas with copper and nickel ions was evaluated using a luminescence spectrofluorometer.

The novel synthesized carbamates are selective inhibitors of the BuChE enzyme. According to molecular docking calculations, the carbamoyl group is close to the key residues of the catalytic triad.

A Fe₃O₄ magnetic nanoparticle modified by sodium dodecyl sulfate was synthesized for preconcentration and determination of uranium(VI) as an uranium(VI)-oxine complex. The method shows appropriate detectability, linearity, precision and accuracy and can be applied for the analyses of natural waters, granite rocks, urine and blood serum samples.

The figure shows the micrography of black carbon spheres and its elementary composition in sediment sample of Guanabara Bay by SEM/EDX.

This scheme shows the proposed method for the determination of nickel after preconcentration using cold-induced aggregation microextraction (CIAME).

Enantioseparation of trans-Fmoc-POAC spin label.

Oxadiazole derivative on multi-walled carbon nanotubes glassy carbon electrode was constructed by electrodeposition of oxadiazole on a MWCNT modified GCE. OMWCNT-GCE exhibits excellent electrocatalytic activity for dopamine oxidation. This modified electrode resolved the overlapping of the anodic peaks DA, AC and Trp.

Isoflavones 1-3 are new natural products isolated from the leaves of Vatairea guianensis Aublé. The ethanol extract from the leaves and the isolated compounds (1-3) were evaluated for their potential scavenging DPPH^•.

Cobalt tetrasulfophthalocyanine was anchored onto the surface of NH₂-MCM-41 and NH₂-MCM-48. Physical mixtures of CoPc in MCM-41 and in MCM-48 were also prepared. The catalytic properties of these materials were studied in the aerobic epoxidation of cyclohexene.

This work supports the existence of a slow relaxation mode in polymer solutions due to diffusion and the internal motions of these transient clusters for poly(acrylamide-co-dihexylacrylamide) (PAHM-0) and poly(acrylamide-co-sodium acrylate-co-dihexylacrylamide) (PAHM-21) to the self-diffusion of individual chains retarded by interchain friction.

A method for mercury quantification in leaves and soil samples by direct sample combustion analysis was assessed and validated.