Sulfur fractionation using high-resolution continuum source molecular absorption spectrometry with calcium and hydrophobic palladium nanoparticles as chemical modifiers.

The unprecedented use of high-resolution continuum source molecular absorption spectrometry (HR-CS MAS) for the fractionation of organic and inorganic sulfur (S) species through monitoring the CS molecule is presented here. Two separate methods for determining organic (CS) and inorganic (CS) sulfur were developed to work sequentially. The optimized temperature program for both methodologies has two pyrolysis steps and one vaporization step (1st T: 1800 and 2T: 800 °C, and T: 2500 °C).

Changes in phytochemical composition of Merlot grape and wine induced by the direct application of boron.

In this study the effect of the direct application of different concentrations of boron in grape bunches on the phytochemical composition of grapes and wine was evaluated. The experiment was carried out by direct application to the grape bunch of different concentrations (0, 1.0, 2.

A high-performance electrochemical sensor based on a mesoporous silica/titania material and cobalt(II) phthalocyanine for sensitive pentachlorophenol determination.

The synthesis and characterization of a novel titania/silica hybrid xerogel subsequently modified with 4-methylpyridine (4-Pic), named TiSi4PicCl is reported. The physicochemical, structural and thermal properties of TiSi4PicCl were characterized using several techniques. Anchoring cobalt(II) phthalocyanine (CoTsPc) in TiSi4PicCl showed greater electroanalytical sensitivity over other sensors built with these materials.

Fast and effective simultaneous determination of metals in soil samples by ultrasound-assisted extraction and flame atomic absorption spectrometry: assessment of trace elements contamination in agricultural and native forest soils from Paraná - Brazil.

This study proposes a simple and effective method for determination of Al, Cd, Cu, Ni, and Zn in soil samples, associating ultrasound-assisted extraction and flame atomic absorption spectrometry (FAAS). Ultrasound-assisted extraction conditions were optimized using a central composite design. This method required small volumes of HCl, HNO, and HF as an extraction solvent blend to ensure effective analyte extraction.

Chemometric Authentication of Brazilian Coffees Based on Chemical Profiling.

In this work, different chemometric tools were compared to classify n = 26 conventional (CONV) and n = 19 organic (ORG) coffees from the main Brazilian producing regions based on the chemical composition, physicochemical properties, and antioxidant activity. Principal component analysis separated ORG and CONV coffees but the distinction among the producing regions of Brazilian coffee was not possible. Partial least squares discriminant analysis classified all ORG and CONV coffees in the external validation.

Comparision of photocatalysis and photolysis processes for arsenic oxidation in water.

The oxidation of As(III) to As(V) in aqueous solution was evaluated using heterogeneous photocatalysis and photolysis. The influence of TiO as catalyst in different crystalline (rutile, anatase) and commercial forms was evaluated in a batch reactor and an insignificant difference was observed between them. The process by photocatalysis reached up to 97% As(III) oxidation and no significant difference was observed comparing to results obtained by photolysis.

Textile dye removal from aqueous solutions by malt bagasse: Isotherm, kinetic and thermodynamic studies.

The biosorption of orange solimax TGL 182% (OS-TGL) textile dye onto new and low cost biossorbent (malt bagasse) in aqueous solutions was investigated. The malt bagasse was characterized by Fourier transform infrared spectroscopy and specific surface area (BET method).Batch biosorption experiments were conducted in order to determine the following parameters: particles size, pH, agitation speed, temperature, contact time, biomass dosage, influence of the ionic strength and, finally, the influence of other textile dye on the OS-TGL biosorption.

Sensor and methodology for dielectric analysis of vegetal oils submitted to thermal stress.

Vegetable oils used in frying food represent a social problem as its destination. The residual oil can be recycled and returned to the production line, as biodiesel, as soap, or as putty. The state of the residual oil is determined according to their physicochemical characteristics whose values define its economically viable destination.

Determination of metals in Brazilian soils by inductively coupled plasma mass spectrometry.

The concentration of metals in Brazilian soil under no-tillage (NT) and an area under native vegetation (NV) was determined by inductively coupled plasma mass spectrometry. The applied method was based on microwave-assisted acid digestion using HNO3, HCl, H2O2, and HF. The accuracy of the method was evaluated by analyzing two certified reference materials (BCR-142 and RS-3).

Determination of Co, Cu, Fe, Mn, Ni and V in diesel and biodiesel samples by ETV-ICP-MST.

This work presents the determination of Co, Cu, Fe, Mn, Ni and V in diesel and biodiesel samples by ETV-ICP MS using emulsion sample preparation. The emulsion composition was: 1.0 g of the diesel or biodiesel sample, 2.