The assessment of chlorine, fluorine, and sulfur concentrations in depth profile of drill cuttings was performed using ion chromatography after sample preparation by pyrohydrolysis. The parameters for pyrohydrolysis were optimized using a Box-Behnken design, and the established conditions were 300 mg of sample, 300 mg of V2O5, temperature of 1000 °C, reaction time of 25 min, and absorbing solution of 50 mmol L-1 NH3 + 150 mmol L-1 H2O2. The accuracy was evaluated by the analysis of certified reference materials and recovery tests, and the results showed a good agreement between determined and certified values and recoveries (89-108%). The precision (relative standard deviation (RSD) < 10%), and the limits of detection (0.5-2.5 mg kg 1) were suitable for drill cuttings analysis. The concentration of chlorine, fluorine, and sulfur in drill cuttings at different depths was at mg g-1 range, and its variation is related to the mineral composition of the samples.

Triclosan (5-chloro-2-(2,4-dichlorophenoxy)phenol) is commonly used as an antibacterial agent in various industrial products and is often detected in wastewater effluent. Comparison was made for triclosan degradation by photolysis and TiO2 photocatalysis (under UV irradiation (125 W)) based on analysis of transformation products, together with ecotoxicity evaluation. The morphology of the TiO2 was characterized by X-ray diffractometry (XRD) and field emission gun-scanning electron microscopy (FEG-SEM). Triclosan quantitation was performed by high performance liquid chromatography (HPLC). The optimal condition was obtained using a response surface model and desirability profile. The initial concentration of triclosan used in all the experiments was 10 mg L-1 to achieve comprehensive identification of transformation products. The optimal experimental condition was 30 mg L-1 TiO2 at pH 10. The photocatalytic system achieved > 99% triclosan degradation at 30 min of reaction. The mineralization rates by photolysis and photocatalysis were 25 and 90%, respectively. A total of 27 transformation products were identified using liquid chromatography quadrupole time of flight mass spectrometry (QTOF MS), being that 25 were new structures, not previously reported in the literature. Ecotoxicity assays demonstrated that triclosan and some of the major transformation products did not cause deleterious effects towards Lactuca sativa and Daphnia magna after 16 h of treatment.

The ultrasound-assisted extraction (UAE) is an alternative approach for the total lipid content determination in food samples. The high extraction efficiency, being less time-consuming and with the possibility of using less toxic solvents are the main advantages of UAE. It is, thus, an excellent alternative to be applied as a laboratory experiment for undergraduate students. The UAE procedure was optimized and the extraction parameters, such as extractor solvent, time and frequency of the ultrasound, were evaluated. The accuracy of the UAE procedure was evaluated by comparing the obtained results with those found by the traditional lipids extraction approach. The results showed that the lipids content found in the analyzed samples by using UAE were in agreement with the results obtained by the traditional lipids extraction. Therefore, the optimized UAE procedure was proposed as a laboratory experiment to 15 groups of undergraduate students to introduce the subjects of an alternative approach for total lipids determination in food samples. The results obtained showed that 80% of the student groups found results for total lipid contents in agreement with those found by traditional lipids extraction method. The proposed UAE procedure as a laboratory experiment proved to be simple and easy to be applied to undergraduate students.

Extracts of black mulberry leaves present phytochemicals such as phenolic compounds and minerals. These substances have been studied because they show several health benefits. In this work we report the influence of drying temperature, infusion temperature and extraction time by means of factorial design monitoring the total phenolic content (CFT) of aqueous extracts of leaves of Morus nigra L. The concentrations of CFT, flavonoids, flavonols and antioxidant activity of the extracts were determined by spectrophotometry. The identification and quantification of phenolic compounds were performed by LC-ESI-MS / MS. The determination of the mineral concentration in the black mulberry leaves was performed by ICP-MS. The Pareto and surface response graphs suggested that the most efficient extractions occurred for leaves drying at lower temperatures and using higher infusion temperatures, extraction time did not show significant influence. The extracts presented concentration of CFT from 16.96 ± 0.15 to 5.73 ± 0.33 mg GAE g-1. The analyzes by LC-ESI-MS / MS allowed to identify phenolic substances not yet reported in the literature to date. In addition 10 mineral elements were determined in the black mulberry leaves at mg kg-1 concentrations range.

This study describes the application of new and low cost biosorbent, shells of urucum (Bixa Orellana), for removal of lead ions (Pb(II)) from water solution. The urucum shells were characterized by Fourier transform infrared spectroscopy and scanning electron microscopy techniques. Batch adsorption experiments were performed in order to evaluate the effect of pH, agitation speed, adsorbent dosage, contact time, temperature, presence of interfering ions and matrix effect on the adsorption of process. The kinetics of biosorption followed pseudo-second-order model. Langmuir and Freundlich isotherm models were applied to describe the biosorption of Pb(II) by urucum shells. The Langmuir model showed better fit and the estimated biosorption capacity was 43.6 mg g-1. The negative Gibbs free energy, ΔG°, confirms the spontaneous nature and positive value of enthalpy, ΔH°, the endothermic character of the process. Furthermore, we also performed an evaluation of matrix and others ions effect on the biosorption process.

A simple strategy using an atomic absorption spectrometer (AAS) for the direct determination of molecular compounds is proposed. The determination of caffeine and propranolol employing atomic absorption instrumentation was conducted, monitoring the emission lines of Fe (271.9 nm) and Mg (285.2 nm), respectively, using a quartz cuvette (1.0 cm) positioned in the burner head. Samples or standards were inserted into the cuvette in order to obtain the absorbance measurements. The parameters of merit were evaluated and the limits of detection were 0.46 and 0.56 mg L-1 for caffeine and propranolol, respectively, with a coefficient of determination R2 > 0.999. The methods developed were applied to the determination of caffeine and propranolol in real samples of beverages and pharmaceutical formulations, respectively. To evaluate the accuracy of the proposed methodologies the results obtained by atomic absorption spectrometer were compared with those obtained by molecular absorption spectrophotometry (UV-Vis) and high performance liquid chromatography (HPLC) or capillary electrophoresis (CE).

A simple procedure for ultrasound-assisted extraction and colorimetric determination of iron in soil samples was developed. The iron concentration in the analyzed samples was determined by the colorimetric method and the results compared with inductively coupled plasma mass spectrometry (ICP-MS). Fifteen soil samples were analyzed and the iron concentration results compared with those obtained by ICP-MS using microwave-assisted sample digestion. The proposed procedure showed good efficiency for iron extraction and the results obtained by colorimetric determination exhibited good agreement with ICP-MS. Moreover, ultrasound-assisted extraction and colorimetric determination is a simple, fast and low-cost procedure for application in routine analysis.

Diferentes calibrações e modificadores foram testados para a determinação de Cd, Pb e Tl em biodiesel por espectrometria de absorção atômica em forno de grafite (GF AAS). Foram preparadas microemulsões usando-se 2 g de biodiesel, 1 mL de solução aquosa de ácido nítrico 10% (v/v) e n-propanol até o volume final de 10 mL. As temperaturas de pirólise foram: 600 °C para Cd e Tl com Pd como modificador permanente e 800 °C para Pb com Ru como modificador permanente. As temperaturas de atomização também foram otimizadas. A calibração aquosa não corrigiu as interferências não espectrais, mas a calibração com simulação de matriz produziu resultados exatos com recuperações entre 80 e 116%. Os valores de RSD foram menores do que 8% para e Cd e Pb com valores de LOD de 0,5 ng g-1 para Cd, 6 ng g-1 para Pb e 1 ng g-1 para Tl. Os resultados obtidos usando-se calibração pelo método de adições de analito e por simulação de matriz foram concordantes. Padrões organometálicos não foram necessários. Diferentes amostras de biodiesel foram analisadas.

Different calibration approaches and modifiers were tested for Cd, Pb and Tl determination in biodiesel by graphite furnace atomic absorption spectrometry (GF AAS). Microemulsions were prepared by mixing 2 g of biodiesel, 1 mL of a 10% (v/v) nitric acid aqueous solution and n-propanol to a 10 mL final volume. Pyrolysis temperatures of 600 °C for Cd and Tl with Pd as permanent modifier, and 800 °C for Pb with Ru as permanent modifier were used. Atomization temperatures were also optimized. Calibration solution prepared in aqueous medium did not correct non-spectral interferences, but matrix matching calibration using base oil led to accurate results with recoveries from 80 to 116%. The RSD values were lower than 8% for Cd and Pb and the LOD values were 0.5 ng g-1 for Cd, 6 ng g-1 for Pb and 1 ng g-1 for Tl. The obtained results using the analyte additions method or by matrix matching calibration were in agreement, confirming the accuracy of the proposed procedure. Organometallic standards were not required and different samples were analyzed.

The wine grape (Vitis vinifera) cv. Cabernet Sauvignon has recently been introduced at a 1160 m altitude in the São Joaquim área (Santa Catarina State, Southern Brazil). The aim of this work was to evalúate the maturation of Cabernet Sauvignon grapes subjected to a Y training system or a vertical shoot positioning trellis (VSP). Grapes were sampled at 10-day intervals throughout their maturation during two consecutive vintage years (2004-2005 and 2005-2006). Climate data were assessed. Based on the results obtained in both vintage years at maturity, titratable acidities (TA) ranged from 0.67 to 0.85 g-100 mL-1 of tartaric with the pH fluctuating between 3.49 and 3.77. The maturation Índex (total soluble solids/TA) at maturity ranged from 26 to 35, and was always higher for berries from the VSP system. Significant differences were observed for the anthocyanin content (TMA) and total polyphenol Índex (TPI) valúes that may be attributed to differences in vintage year and climate conditions. Climatic conditions strongly influenced the grape quality, and it is important to note that São Joaquim is a warm región according to the Winkler scale, with 1668-1944 GDD °C. Under these environmental conditions, the VSP system provided better results for TSS, berry weight and acidity than the Y system, which could be seen more clearly in 2005-2006 due to lower rainfall.

El objetivo de este trabajo fue evaluar la maduración de uvas Cabernet Sauvignon bajo dos sistemas de conducción: sistema en Y y sistema de espaldera alta (VSP). Las viñas han sido cultivadas recientemente en la ciudad de São Joaquim, Estado de Santa Catarina (Brasil), a 1160m de altitud. Las uvas fueron muestreadas para el análisis de su maduración en dos vendimias consecutivas, 2004-2005 y 2005-2006, cada 10 días, desde envero a cosecha. Parámetros del mesoclima también fueron determinados. Los resultados muestran que a madurez, en ambas vendimias los valores de acidez total (TA) fluctuaron entre 0,67 y 0,85 g-100 mL-1 de ácido tartárico y el pH entre 3,49 y 3,77. En general, TA a madurez fue más baja en 2004-2005 que en 2005-2006. El índice de maduración (sólidos solubles totales/TA) en la madurez varió desde 26 a 35, y fue más alto para bayas cultivadas en VSP. Se observaron diferencias significativas en los valores de antocianas y en el índice de los polifenoles totales (TPI); la vendimia y el clima explicaron las fuertes diferencias entre los niveles de antocianas y TPI. Las condiciones climáticas influyeron fuertemente en la calidad de la uva. En Sao Joaquim, el clima fue clasificado como 'Región III', según la Escala de Winkler, una región cálida (1668 a 1944 °C). En general, el sistema VSP dio mejores resultados en lo referente a TSS, peso de la baya y acidez los que se percibieron más claramente en 2006 debido al menor nivel de precipitaciones.