Determinação do pH de formação do complexo [Fe(o-fen)3]2+

We suggest this research to find the better complexation's pH of [Fe(o-fen)3]2+ complex. The literature says only that this complex is quantitative since pH 2,0 until 9,0. We verify that at pH 9,2 the complex has the largest absorbance, showing that it is the largest pH complexation.We conclude that 9,2 is the ideal pH for the complexation of Fe(lI) with 1, 10-phenantroline, when this complex is free of interferents. Neste trabalho são apresentadas evidências sobre o melhor pH de complexação do complexo [Fe (o-fen)3]2+. A literatura cita que este complexo é quantitativo desde pH=2,0 até 9,0. Verificamos que a pH=9,2 o complexo tem a maior absorbância, demonstrando que este é o pH de maior complexação. Conclui-se que o pH ideal para a comlexação de Fe (II) com o-fenantrolina, quando este complexo encontra-se livre de interferentes, é 9,2

Pesticide Residues Method Validation by UPLC-MS/MS for Accreditation Purposes

The development and validation of an analytical method for the determination of 51 pesticides in tomato using UPLC-MS/MS (ultra performance liquid chromatography coupled to tandem mass spectrometry) was performed in order to fulfill the requirements of the NBR ISO/IEC 17025:2005. The goal of the validation was to evaluate all required parameters, such as linearity of analytical curves, instrument and method limits of detection and quantification, matrix effect and accuracy (trueness and precision). Stock solutions of the pesticides were prepared in organic solvent by two different analysts independently, in order to validate this preparation by comparing the detector response areas of injections (n = 7). Pesticides were extracted from tomatoes applying the Dutch mini-Luke method with 30 mL of each solvent as acetone, petroleum ether as well as dichloromethane. A small aliquot of the organic solvent extract was evaporated and reconstituted in methanol with 0.1% of acetic acid (v/v) for UPLC-MS/MS analysis. The recovery experiments were done by spiking blank samples at 10, 20 and 50 µg kg-1, performed by two analysts, seven replicates for each concentration level plus the blank sample. From the 51 studied compounds, 46 showed recoveries within the acceptable range of 70-120% for all evaluated concentrations. For 82% of pesticides, the validated method limit of quantification was the lowest concentration studied (10 µg kg-1) . The intermediate precision was below 20% for all evaluated pesticides showing excellent repeatability of the method

Impact of the quality of life of inseminators on the results of artificial insemination programs in beef cattle Impacto da qualidade de vida dos inseminadores nos resultados de programas de inseminação artificial em bovinos de corte

The objective of the present study was to evaluate the effect of factors of personal life and work conditions on the results obtained by inseminators in conventional and fixed-timed artificial insemination programs in beef cattle. Inseminators from three farms (21 in the total) were interviewed and evaluated according to the general obtained pregnancy rates. The differences among the pregnancy rates obtained in the farms, motivation and its association with the obtained pregnancy rate and the effect of each variable of the groups of needs on the pregnancy rate at first insemination were evaluated. The open questions were grouped by similarity and then analyzed by frequency of the answers. Pregnancy rates obtained by the inseminators ranged from 12 to 57%, with a mean service index of 3.10 ± 1.62 doses/pregnancy. It was also observed that the satisfaction of biological, financial, and training needs was more intimately related to the pregnancy rate than the satisfaction of the other needs, although none had shown an antagonistic relationship with it. Factors concerned to life quality and to the work can be important in determining the performance of these professionals.<br>Objetivou-se avaliar o efeito de fatores ligados à vida pessoal e ao trabalho sobre os resultados obtidos por inseminadores em programas de inseminação artificial convencional e em tempo fixo em bovinos de corte. Inseminadores de três propriedades rurais (21 no total) foram entrevistados e avaliados quanto à taxa de gestação geral obtida. Foram avaliadas as diferenças entre as taxas de gestação obtidas nas fazendas, a motivação e sua associação com a taxa de gestação obtida e o efeito de cada variável dos grupos de necessidades sobre a taxa de gestação à primeira inseminação. As questões abertas, depois de agrupadas por similaridade, foram analisadas por frequência de respostas. A taxa de gestação obtida pelos inseminadores variou entre 12 e 57%, com índice de serviço de 3,10 ± 1,62 doses/prenhez. A satisfação das necessidades biológicas, financeiras e de treinamento foi mais intimamente relacionada à taxa de gestação que a satisfação das demais necessidades, embora nenhuma delas tenha apresentado relação antagônica com a taxa de gestação. Fatores ligados à qualidade de vida e ao trabalho podem ser importantes na determinação do desempenho dos inseminadores