Análise do teor de cocaína em amostras apreendidas pela polícia utilizando-se a técnica de cromatografia liquida de alta eficiência com detector UV-Vis

The HPLC technique with UV-Vis detection was employed in the analysis of cocaine content in apprehended samples of cocaine and crack. A peak signal for cocaine was obtained in 3.5 minutes run by using acetonitrile/water (95:5v/v) as a mobile phase. Optimized spectrophotometric signal was obtained at a wavelength of 224 nm. The analytical curve from 1.0 to 40.0 ppm of cocaine was obtained, showing a linear correlation coefficient of 0.9989, with detection and quantification limits of 0.75 ppm and 3.78 ppm, respectively. This methodology was employed at the dosage of confiscated samples of cocaine and crack in the Scientific Police Laboratory of Ribeirão Preto-SP city.

Eficiência agronômica da ureia estabilizada com inibidores de urease e nitrificação na cultura do milho

Nitrogen (N) is the most required nutrient for corn plants and, in order to supply this demand in highly productive crops, mineral fertilizers are used, especially urea. The disadvantage of urea is the loss of N-NH3 to atmosphere. To reverse this situation, some technologies have been developed, such as nitrification and urease inhibitors, which are used as additives to urea. This work aimed at evaluating the agronomic efficiency of urea stabilized with urease and nitrification inhibitors applied to cover the 2013/2014 corn crop. We evaluated 11 nitrogen fertilizer applied in coverage: urea + PA (41.6% N, 3% Cu); urea + PA (41.6% N, 1.5% Cu); urea + PA (41.6% N, 3% Zn); urea + PA (41.6% N, 1.5% Zn); urea + PA (41.6% N, 0.34% Cu, 0.94% B); urea + PA (41.6% N, 0.25% Cu, 0.68% B); urea + PA (41.6% N); urea (44.3% N, 0.15% Cu, 0.4% B); urea (43% N, 0.1% Cu, 0.3% B, 0.05% Mo); pearled urea (46% N); urea + 0,8% DMPP (45% N) and the control, which did not receive nitrogen topdressing. The evaluations were: Nitrogen losses through volatilization, content and accumulation of N, boron (B), copper (Cu) and zinc (Zn) to the dry matter of aerial parts, grains, and in straw and grain productivity. Fertilizers stabilized with urease and nitrification inhibitors did not reduce the volatilization of ammonia volatilization, when compared to pearled urea. Urea with 0.8% of DMPP nitrification inhibitor (3,4-dimethylpyrazole phosphate) provided higher loss by volatilization, lower productivity and agronomic efficiency compared to pearled urea. The coating of urea with Cu, B and Zn did not increase the accumulation of these nutrients in grains and MSPA plants. The use of fertilizers stabilized and coated with micronutrients did not increase the productivity and agronomic efficiency compared to conventional urea.

Caracterização mineralógica, química e solubilização do potássio de glauconita modificada

Demand for potassium in Brazil is large and is constantly increasing, but only about 5% of all consumed potassium is produced in the country. This low domestic production implies high rate of potassium imports, leaving the country vulnerable in the event of any difficulty to import this product and currency fluctuations. The modified glauconite is a rock that has a high potential for potassium exploration, found in Minas Gerais state, its extraction is relatively cheap and the prospected rock volume is high. The difficulty for its use as a direct source of potassium is in its low solubility. Thus, the objective of this study was to perform a chemical and mineralogical characterization of the modified glauconite and evaluate the effectiveness of techniques and treatments in the potassium solubilization contained in the rock. For this study, it was used characterization techniques such as X-ray diffraction, scanning electron microscopy, diffraction by Synchrotron Light and chemical analysis of high and low power of potassium extraction. Also granulometric testing and thermal treatments with different forms of calcination were carried out. Overall, it was found that the modified glauconite is a compound of minerals, of the mica groups K-feldspar and quartz and calcination substantially alter the crystal structure of these minerals, increasing the potassium availability. While the natural solubility of glauconite modified be very low, rock calcination added with high fluxes of calcium and low magnesium content at 1200 °C led to potassium solubility increase in order of 100 times compared to that observed in the glauconite natural modified.

Compartimentos de K, Ca e Mg em solos e sua relação com o crescimento inicial, fisiologia e produtividade do eucalipto

Forestry has grown in a continuous and accelerated manner in Brazil, constituting a strategic activity for the generation of employment, income and tributes, favoring social and economic development of Brazilian agribusiness. The objectives of this study were: (1) evaluate the contents of K, Ca and Mg in the reserve compartments, non-interchangeable, interchangeable, available and the speed of its release, its correlations and its effects over productivity (annual average increment – AAI) of eucalyptus plantations, in forest sites cultivated in soils of the state of Rio Grande do Sul; (2) evaluate the initial growth, nutrition and physiological aspects of eucalyptus plants, cultivated with and without the addition of mineral sources of potassium (K), calcium (Ca) and magnesium (MG), in soils obtained from forest sites in the state of Rio Grande do Sul. In the first study, contents of K, Ca and Mg were evaluated in sulfuric digestion extract, boiling nitric acid, ammonium chloride, Mehlich-1 (only K), potassium chloride (Ca and Mg), as well as the release speed of these nutrients in the soil. In the second study, growth variables, nutritional aspects, photosynthetic rate (A) and transpiration rate of the plants (E) grown in distinct soils were evaluated under controlled conditions. The contents of K, Ca and Mg varied between compartments and depths in the studied soil classes, with the highest proportions found in the reserve compartment, indicating the importance of this compartment for the supplement of these nutrients at average and long terms. The great majority of K, Ca and Mg compartments presented significant correlations between each other, showing the dependence between them and the importance of evaluating the contents of these nutrients in the different compartments to adapt the nutritional management of the plants to each soil class, and to obtain continuous productions, minimizing the negative effects to the environment. Plants cultivated in soils that present larger reserves, availability and K, Ca and Mg release kinetics, presented similar height (H), stem diameter (SD) and shoot dry mass (SDM), with or without fertilization with K, Ca and Mg. The plants presented higher leaf content and accumulation of K in all soils fertilized with K, Ca and Mg.