196 resultados para analytical method


Relevância:

60.00% 60.00%

Publicador:

Resumo:

Pós-graduação em Alimentos e Nutrição - FCFAR

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Relevância:

60.00% 60.00%

Publicador:

Resumo:

An analytical method based on liquid chromatography with positive ion electrospray ionization (ESI) coupled to tandem mass spectrometry detection was developed for the determination of pantoprazole (CAS 102625-70-7) in human plasma using lansoprazole (CAS 103577-45-3) as the internal standard. The analyte and internal standard were extracted from the plasma samples by liquid/liquid extraction using diethyl-ether/dichloromethane (70:30; v/v) and chromatographed on a C-8 analytical column. The mobile phase consisted of acetonitrile/water/methanol (57:25:18; v/v/v) + 10 mmol/l acetic acid + 20 mmol/l ammonium acetate. The method has a chromatographic total run time of 4.5 min and was linear within the range 5.0-5,000 ng/mL. Detection was performed on a triple quadrupole tandem mass spectrometer by Multiple Reaction Monitoring (MRM). The intra- and inter-run precisions calculated from quality control (QC) samples were 4.2% and 3.2%, respectively. The accuracies as determined from QC samples were -5.0% (intra-run) and 2.0% (inter-run). The method herein described was employed in a bioequivalence study of two tablet formulations of pantoprazole.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Thin walled cylindrical shells are widely used in many areas of industry, including civil, mechanical, nuclear, marine, petroleum and aerospace engineering. The wide application of thin cylindrical shells and the importance of instability phenomenon are the motivation basis to this study, since these factors have a great importance in engineering projects. It is presented a detailed study about the instability of cylindrical shells based on theoretical calculation, which results are compared with finite elements method calculation. The loading and boundary conditions analyzed are based on the most common types verified in real engineering projects and refer respectively to lateral (external) pressure and cylinders with simply supported edges. The calculation based on the finite elements method was executed with ANSYS 13.0 software. The results obtained with this calculation are in good agreement with the analytical theory presented in the technical note NACA No 1341 (BATDORF, 1947) considering a wide range of applicability. On the other hand, the analytical method presented in the book Theory of Elastic Stability (TIMOSHENKO; GERE, 1936) has a very restrict applicability and has presented considerable deviations in a great sort of the analyzed cases

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Considering that persistent organic pollutants (POPs) including synthetic substances belonging to differents organic functions, including organochlorine pesticides (OCPs), which are the most persistent and bioaccumulative, with high toxicity to humans and animals. Accordingly environmental and biological monitoring is necessary, in order to have greater control regarding the irresponsible use of these products. Though there are several analytical methodology reported in the literature to make determinations of this pesticide, they present some difficulties, requiring several steps to make the clean up of the sample. The proposed project aims to optimize a new analytical method that allows to perform the extraction of organochlorine pesticides in fish tissues, employing acetone as solvent assisted by ultrasound bath, making the method more quickly and not requiringfurther steps to purify the sample. Were analyzed the recoveries of pesticides in study in samples of tilapia average values: Heptachlor=84,7±9,8%; Aldrin=87,3±3,5%; Endosulfan=101,4±18,6%; DDE= 90,5± 3,3%, Endrin=102,2±13,8%., DDD=92,1±19,9%; DDT=90,8±6,8%. The real samples showed values granted for our legislation and low values of error

Relevância:

60.00% 60.00%

Publicador:

Resumo:

The ethyl carbamate is a compound present in most foods yeast-distillates; due to its carcinogenic potential, national legislation has established a limit of 0.150 µg / mL for spirits, so the values above the same, pose a threat to both public health as well for the economic sector by preventing the export of these products. The aim of this work is to provide the optimization of an analytical method employing the technique of gas chromatography equipped with flame ionization detector (FID) to determine the concentration levels of ethyl carbamate in some samples of wine. The use of ethyl acetate as solvent employed in the extraction, the ethyl carbamate present in wine samples proved to be suitable, where Recoveries were between 97.6 to 103.3% (m / m), with a standard deviation for between 0.56 to 3.50%. The concentrations of ethyl carbamate in particular wine samples vary between 3.22 µg / ml and 3.80 µg / mL, with a mean of 3.48 µg / mL. These valuesare all above the limit set by law. Thus, the results indicate the need for changes in the process of wine production, in order to control the levels of the substance

Relevância:

60.00% 60.00%

Publicador:

Resumo:

This work aims to determine the stresses acting on the main beam of a crane to transport steel coils of up to twelve tons. To determine the stress it was made a revision of the knowledge of the mechanics of materials to apply the analytical method. Following a review of the finite element method is made to understand the same. To complete the study it was used the commercial software ANSYS to determine the stresses by finite element method, the program provides images that help to better understand the results obtained. With the results a comparison of the values of the tensions between the two methods (analytical and finite element) was made. To assist in the calculations it was used the NBR 8400, 1984 (Calculation of Lifting Equipment Load)

Relevância:

60.00% 60.00%

Publicador:

Resumo:

A biomimetic sensor is proposed as a promising new analytical method for determination of norfloxacin (NF) in pharmaceuticals. The sensor was prepared by modifying a glassy carbon electrode surface with a Nafion® membrane doped with poly(copper phthalocyanine) complex [poly-CuPc]. Amperometric measurements carried out with the sensor under an applied potential of -0.05 V vs Ag|AgCl in 0.1 mol L-1 acetic acid containing 1.5 × 10-3 mol L-1 hydrogen peroxide showed a linear response range from 2.0 × 10-4 to 1.2 × 10-3 mol L-1. Selectivity and interference studies were also performed. A sensor response mechanism is proposed, based on the experimental evidence. Recovery studies were carried out using environmental samples, in order to evaluate the sensor’s potential for use with these sample classes. Finally, sensor performance was evaluated using analyses of commercial formulations.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

This article proposes a reflection on a place for epistemological studies about the Bakhtin Circle, as well as it also reflects on the perspectives of Brazilian approaches to that. It also sheds light to the issues concerning the production, the circulation and the reception of works of the Russian Circle in order to understand why, in Brazil, we can speak of Dialogic Discourse Analysis (DDA), affiliating the so-called dialogical philosophy of language to an analytical theory, grounded in the relation between linguistics and cross-linguistics. In order to do that, this paper focuses on the notions of dialogue, ideological sign, subject and exotopia. The hypothesis put forward is that, unlike other Analyzes of Discourses, the theoretical-analytical method of the Circle is dialogical. This is the peculiarity of its proposal.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

After two decades advertising and defending the synthetic method, João Köpke became active disseminator of analytical method for teaching reading. In five te xts published between 1896 and 1917, produced in different circumstance s for different publics readers, Köpke seeks the support of American and European authors, for their principles as well as for the education experience, to his analytical method. as by theirs principles as by theirs educational experiences. Among those authors: J. Jacotot, A. Bain, A. Meiklejohn, J. Froebel, C. Parker, G. Stanley Hall and J. Chubb. In this article, attention is given to repeated American references with special emphasis on the psychology of Stanley Hall and the method of teaching reading of Meiklejohn, highlighted and placed on convergence by Köpke in his final writings.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Pós-graduação em Agronomia (Proteção de Plantas) - FCA