JBCS

Cocaine samples seized in several Brazilian states between 2009 and 2012 were analyzed by the Federal Police chemical profiling program (PeQui project). Cocaine purity, degree of oxidation and pharmaceutical products used as cutting agents were determined by gas chromatography-flame ionization detector (GC-FID) analysis.

Molecular imprinting is a technique that creates recognition sites specific for a target molecule within a synthetic polymer. The so-called molecular imprinting polymers are rigid polymeric materials that present high molecular recognition properties for a target molecule called template. After polymerization, the template is extracted from the polymer network, leaving its imprinting in the polymer structure.

X-ray diffraction, nuclear magnetic resonance analysis and theoretical methodology were applied to the bioactive clerodane t-DCTN resulting in good correlations between experimental (obtained in a 600 MHz equipment) and theoretical magnetic properties (from B3LYP/6-311G++(d,p)).

Two new biflavonoids, amburanins (1) A and B (2), isolated from the trunk bark of Amburana cearensis, inhibited human neutrophil degranulation and myeloperoxidase activity, demonstrating a potential anti-inflammatory effect.

Kinetic and thermodynamic studies of the adsorption of 1-(2 thiazolylazo)-2-naphtol on XAD-7 or silica gel aiming the selection of the best adsorbent for solid-phase extraction.

A simple rapidly synergistic cloud point extraction procedure has been developed for the separation and preconcentration of trace amounts of lead from food and water samples by flame atomic absorption spectrometry (FAAS).

It was assessed the concentrations of metals (Al, Cr, Cu, K, Mn, Ni, Pb e Zn) in superficial and core sediments from 5 sampling sites along the Turvo/Grande hydrographic basin. Principal Component Analysis (PCA) and Pearson's correlation matrix were performed to evaluate the source of metals. Zn has anthropic contribution in sites from the urban area, while Al, Mn, K and N at the site in rural area are from agricultural runoff.

The determination of fatty acids (FA) in liver from three different groups of Wistar rats submitted to different diets (AIN93G) by capillary zone electrophoresis (CZE) signals as an interesting alternative to biologic analysis when chemometrics is associated to histopathologic analysis.

The opportunity of converting post-consumer plastic materials into food contact packaging requires the development of reliable analytical methods to determine the potential migration of residual contaminants, in order to ensure the package safety for its intended use. In this study post-consumer PET and HDPE, submitted to several cleaning process, were evaluated to migration tests for determination of nonvolatile and inorganic elements.

This study developed an analytical method for high performance liquid chromatography (HPLC) with fluorometric detection for quantification of itraconazole in poly lactic-co-glycolic acid nanoparticles, plasma and tissue, which is sensitive, low cost, viable for routine usage and with potential for application in itraconazole biodistribution and pharmacokinetics studies.

One new flavonoid, quercetin-3-O-α-L-rhamnopyranosil-(1→4)-β-D-glucopyranoside, together with kaempferol-3-O-α-L-rhamnopyranosyl-(1→4)-β-D-glucopyranoside, rutin, and kaempferol-3-O-rutinoside were isolated from the leaves of Oxandra sessiliflora R. E. Fries (Annonaceae). The structure of the compound was elucidated by spectroscopic methods, including extensive 1D and 2D-nuclear magnetic resonance (NMR) techniques.

A new method based on combination of NP based SPE with spectrofluorimetric detection has been developed for the extraction and determination of trace amounts of carbaryl in environmental water samples.

Ni- and C-rich islands associated to presence of pores on polymer-derived ceramics contributed to the formation of ultra-long nanowires at high temperature.

BiVO₄ photoelectrodes when irradiated with light promote an augmentation in photocurrent.

Directly suspended droplet microextraction (DSDME) combined with flame atomic absorption spectrophotometry (FAAS) was developed for the first time for determination of Cu (II) and Fe (III) in different samples. DSDME provides more flexibility and simplicity in the choice of the operational extraction parameters and does not need any special glass tube for extraction and solvent collection.

The presence of some inorganic elements in biodiesel has a direct influence on the engine performance and fuel behavior. In this context, the quantification of several elements becomes necessary to evaluate fuel quality and to control the pollutant emission. A decomposition procedure for oil based samples using a high pressure asher was evaluated.

The effects of impregnation methods and drying conditions on the structure and catalytic behavior of MCM-41-supported Ni-W catalysts were investigated. Co-impregnation and drying under vacuum favoured the formation of octahedrally coordinated W species that could be easily sulfided and involved in the genesis of active sites with high HDN catalytic performances.

Biodiesel was degraded in contact with water. Fenton's reagent and UV-Vis light was used to speed up the process.

A rapid and variable-volume sample loading scheme for nonaqueous microchip electrophoresis with laser induced fluorescence detection (NAMCE-LIF) has been developed, which includes a porous polymer plug, a microvacuum pump, and a single potential supply.

We have developed a novel "two-step" chemiluminescent method for the quantitation of acyl-CoA oxidase activity based on the chemiluminescent reaction between the H₂O₂ produced during the acyl-CoA oxidase-catalyzed reaction and luminol.

Schematic illustration of the analytical approach for determination of 5-hydroxytryptophan (5 HTP) in dietary supplements.

Rodriguesic acid and rodriguesic acid hydroxamate are the first diketopiperazines isolated from a marine mollusc. A carboxylic acid replacing the terminal methyl group of an alkyl chain constitutes an unusual structural feature of both rodriguesic acids.