JBCS

The lower NO emission during weekends promotes ozone accumulation in Rio de Janeiro city.

One new homolycorine-type alkaloid, 2α-10bα-dihydroxy-9-O-demethylhomolycorine, in addition to seven known were isolated from the bulbs of Hippeastrum solandriflorum (Amaryllidaceae). Their structures were determined by spectrometric methods. Two compounds exhibited significant cytotoxic activity

Essential, nonessential and potentially toxic elements were determined in graviola pulp by inductively coupled plasma optical emission spectrometry (ICP OES) and graphite furnace atomic absorption spectrometry (GF AAS). Graviola can be considered a good source of B, Cu, K, Mg and Mn.

A direct solid sampling high-resolution continuum source graphite furnace atomic absorption spectrometry (HR-CS GF AAS) procedure with calibration using aqueous standards was employed for the determination of Cd, Ni and V in spices.

Quick, easy, cheap, effective, rugged and safe (QuEChERS) was used to determine pesticides in tomato after washing treatments. Liquid chromatography tandem mass spectrometry (LC-MS/MS) in dynamic multiple-reaction monitoring mode (DMRM) was used for the detection of compounds. Washing and peeling before consumption contributes to reduce pesticide residues in tomato.

A nitrite electrochemical sensor was prepared by depositing polyaniline (PANI) on graphene (GR) and ferrocenecarboxylic acid (FCA) modified electrode. The modified electrode has a highly catalytic activity for the oxidation of NO₂^- and was applied to detect NO₂^- sensitively.

Methyl salicylate has firstly been demonstrated as an alternative extraction solvent for dispersive liquid-liquid microextraction of benzimidazole fungicides in environmental water samples. The method is simple, rapid, low cost, and reliable for trace analysis of fungicides.

Antioxidant systems, Fe, Cu, Zn, Mn and Ni levels and proteomics in soybean seeds of different performance in field were assessed. Basal superoxide content and Zn level contribute to predict a possible poor performance in field.

A multivariate model for near-infrared (NIR) spectrometric analysis of natural gas is developed by using calibration mixtures prepared by an automatic system.

A new electrode based on carbon nanotube and Cu(phen)₂(TCNQ)₃ was developed. The Cu(phen)₃(TCNQ)₂/CNT modified glassy carbon electrode showed an excellent electrocatalytic activity toward urate oxidation. The sensor was successfully applied to urate determination in urine samples.

In this work, a dispersive liquid-liquid microextraction method based on solidification of organic drop (DLLME-SFO) followed by high performance liquid chromatography (HPLC) was applied to determine the amount of two nitrophenols in water samples. The effect of the main experimental variables on the extraction procedure was investigated and optimized by the experimental design method.

The extraction process of bioactive compounds from the propolis produced by selected bees was optimized using a 2³ factorial design and the extract produced in the optimal condition was evaluated determining its chemical composition and antioxidant activity.

Sequential injection manifold for determination of the free picloram concentrations employing square wave voltammetry.

The sensor, based on hemin, is a viable alternative for the determination of hydrochlorothiazide in a simple, rapid, selective and sensitive way for the application in doping and quality control.

Considering the importance of pesticide residues monitoring programs in drinking water to attend the legislations, reliable methods with high detectability and selectivity are required. A method for the determination of 70 pesticide residues in drinking water using solid phase extraction (SPE) with polymeric sorbent and gas chromatography coupled to tandem mass spectrometry (GC-MS/MS) and liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) was developed and validated.

Photomicrograph of Sphaerocavum brasiliense colony (scale bar = 20 µm, 400×). Source: Watson A. Gama.

Rosemary (Rosmarinus officinalis L.) is an excellent source of natural antioxidants for the emulsion systems. The higher gains in lipid protection were obtained by oil-in-water systems, principally.

This study reports a rapid green click synthesis of novel fluorinated 1,2,3-triazole diesters under solvent-free conditions. The resulting diesters were converted to their corresponding bishydrazones and evaluated for their antimicrobial activity.

Petroleum refining wastes are potential source of Hg and consequently harmful to environment and humans but it could be an alternative source of energy.

Ionic conductivity values of binary solutions containing ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate (BMI.BF₄) and ethylene glycol at different concentrations and over a wide temperature range.

Biodiesel press cake combined with Fe produces reactive composites supported on carbon to be used in Cr^VI removal.

A simple and clean methodology employing a combined spot test/diffuse reflectance spectroscopy procedure was developed and applied for analysis of lead in progressive hair dyes, using a filter paper platform.

Simple fractionation procedures allowed the chemical speciation of Fe and the study of cooking effects on the distribution of Fe-species in seven different varieties of Phaseolus beans. Soluble and inorganic iron concentration suffered alterations due to cooking.

Application of bar adsorptive microextraction for the analysis of environmental water and wine matrices using floating sampling technology.

A novel electroanalytical method was developed for the simultaneous determination of paracetamol and codeine in pharmaceutical formulations and human body fluids. The method involves the combination of square-wave voltammetry with a cathodically pretreated boron-doped diamond electrode.