Composting is a sustainable approach to manage animal and vegetal waste generated in the Fundação Parque Zoológico de São Paulo. The resulting compost is often used in ZOO's premises as an organic fertilizer for the production of vegetables, which is further used to feed the animals. The composting product provides many forms of mineral and also amino acids (AA) that are absorbed by plants as nutrients. Since most amino acids absorb only slightly or not at all in the UV wavelengths, we developed a method for the determination of AA of agricultural interest in the composting samples. Due to the complexity of samples, we used ion exchange chromatography for the purification of AA prior to analysis. The proposed CZE-C D method allowed a separation of the AA in a short analysis time (less than 3.0 min), with great linearity (with R ranging from 0.993 to 0.998). Using a BGE of 10 mmol/L TEA, reduction of high-frequency noise and lower baseline fluctuations were obtained. The LOQ for the five AA were around 35 μmol/L, and were adequate for our purpose. In addition, the method showed good precision (RSD of peak area and migration time less than 1.55 and 1.16%, respectively).

No presente trabalho, três colunas capilares, uma sem recobrimento interno e duas com recobrimentos internos diferentes foram utilizadas na separação de fragmentos de DNA: poli(vinil álcool) (PVA) e poli(dimetilacrilamida) (PDMA) -ambos de recobrimento covalente -foram comparados para a separação de DNA utilizando soluções poliméricas. As separações foram realizadas usando hidroxietilcelulose (HEC) (90-105 kDa) nas concentrações entre 0,00 e 2,00% m/v. Os resultados indicaram que a eficiência de separação foi maior no capilar de PVA do que no de PDMA, em todas as concentrações de HEC testadas. Ainda, uma resolução superior também foi observada com o capilar de PVA, já que com o capilar de PDMA o formato dos picos não se mostrou reprodutível quando corridas subseqüentes foram realizadas. Contrariamente ao relatado na literatura, nenhuma separação foi conseguida com o capilar sem revestimento interno.In this work three capillary columns, one with uncoated inner wall and two with covalentlybound internal coatings -poly(vinyl alcohol) (PVA) and poly(dimethylacrylamide) (PDMA) -both covalently covered -were used to separate DNA fragments and compared to DNA separation using replaceable polymer solutions. The separations were performed using hydroxyethylcellulose (HEC) (90-105 kDa) in concentrations ranging from 0.00 to 2.00% m/v. The results indicated that the separation efficiency was higher in the PVA capillary than in the PDMA in all evaluated concentrations of HEC. In addition, higher resolution was also observed in PVA-coated capillary since in PDMA the shape of the peaks was not reproducible when subsequent runs were performed. Contrary to what has previously been reported in the literature, no reasonable separation was possible in bare fused silica.Keywords: DNA separation, capillary coating, laser-induced fluorescence, PDMA, PVA IntroductionCapillary electrophoresis (CE) is a separation technique widely used for separation of biological macromolecules. It offers great advantages over slab-gel electrophoresis (SGE) -shorter analysis time, smaller quantity of sample, greater efficiency of separation, and easier automation. 1,2 The first attempts to apply CE to DNA separations were carried out in capillaries filled with cross-linked gels, like polyacrylamide. [3][4][5] Later on, some polymeric solutions were used, known as dynamic or physical gels, which are easily prepared and introduced into the capillary, thus enabling its renewal after each analysis and the use of a single capillary for many separations, without any problem with the subsequent separations. 6 DNA migration mechanisms in polymeric matricesThe Ogston and the reptation models were first proposed to explain DNA migration in slab gels, but they have also shown themselves suitable for polymeric solutions. 7 According to the Ogston theory, the DNA fragment keeps a spherical and rigid conformation of radius Rg. This particle moves across a random net formed by the gel fibers. These fibers form pores with average size ξ, which is a function of the po...

One of the problems with 2DE is that proteins present in low amounts in a sample are usually not detected, since their signals are masked by the predominant proteins. The elimination of these abundant proteins is not a guaranteed solution to achieve the desired results. The main objective of this study was the comparison of common and simple methodologies employed for 2DE analysis followed by MS identification, focusing on a pre-purified sample using a wheat germ agglutinin (WGA) column. Adult male C57Black/Crj6 (C57BL/6) mice were chosen as the model animal in this study; the gastrocnemius muscles were collected and processed for the experiments. The initial fractionation with succinylated WGA was successful for the elimination of the most abundant proteins. Two quantification methods were employed for the purified samples, and bicinchoninic acid (BCA) was proven to be most reliable for the quantification of glycoproteins. The gel staining method, however, was found to be decisive for the detection of specific proteins, since their structures affect the interaction of the dye with the peptide backbone. The Coomassie Blue R-250 dye very weakly stained the gel with the WGA purified sample. When the same gel was stained with silver nitrate, however, MS could positively assign 12 new spots. The structure of the referred proteins was not found to be prone to interaction with Coomassie blue.

Electrophoresis 2016, 37, 2449–2457. DOI: If an average household produces weekly several pounds of organic garbage, imagine the volume of a large zoo like São Paulo Zoo. The amount of organic waste, from feeding left overs, to plants, manure and even dead animals, is enough to produce up to 120 tons monthly. If all this organic matter was sent to dumping grounds, this would create a serious environmental problem. Composting is a sustainable approach by the São Paulo Zoo to manage animal and vegetal waste generated in the Zoo's premises. The resulting compost is often used as organic fertiliser for the production of vegetables, which is further used to feed the animals. The compost produced provides many forms of minerals and also amino acids (AA) that are used by plants as nutrients. Since most amino acids absorb only slightly or not at all in the UV wavelengths, we developed a method for the determination of AA of agricultural interest in the compost samples. Due to the complexity of these samples, we used ion exchange chromatography for purification of AA prior analysis. The proposed CZE‐C4Dmethod allowed a separation of the AA in a short analysis time (less than 3.0 min) without the need for derivatization, with sensitivity and reproducibility suitable for such samples. Photograph: Paulo Gil