Repositório RCAAP

In this work it was studied possible solutions for the problems decurrents of the undue evasion of residues in the environment on the Laboratório on Separação and Préconcentração (LSPc) of the Chemistry Institut in the Universidade Federal de Uberlândia. From considerations above, some procedures realized by several Federal Instituts that helped to minimize suchs disorders, how the implement by program to administrastion in residues ruled in a removal of posture, beyond of to require one continuous reeducation for part in the professionals in above mentioned laboratorys. In short, the rationalizetion of procedures to aim at one under consumption in reagents and consequent, reduction of worns values with the reagents and younger impact environment. With adequates procedures adopted in the LSPc, it was verified the conscience of the users at relation on adequates evasion and label from residues generated in the laboratory in question. It was realized one survey of the inventory of the passive existent in the LSPc. After this survey, it was effectuated the treatment of the residues utilizing technics of separation phasis, distillation and filtration, where went possible the recuperation of the solvents etanol, chloroform and from the 1-(2-pyridylazo)-2-naphthol (PAN). The solvent methyl-isobutyl-ketone, the tenoyltrifluoroacetone and the 8-hydroxyquinoline not went recuperated.The metals lead, iron, copper, zinc and manganese was not determineds. The concentration of cadmium (II) determined was of 5,73.10-3 mg.dm-3, whose value to meet below of the value maximum permited (VMP) that to be of 0,01 mg.dm-3. The total size of the etanol and chloroform recovereds was 13,0 L and 3,8 L, respective generate a total economy of the R$ 99,53 for the instituion. For to recover the PAN there was a economy of the R$ 52,00, seen that the recovered mass of this composed was of the 1,840 g.

Conselho Nacional de Desenvolvimento Científico e Tecnológico

This work, a procedure for separation and preconcentration of chromium (III) by cloud point extraction and determination by flame atomic absorption spectrometry in mineral water samples was developed. This procedure is based on the formation of the complex of Cr(III) with PAN (1-(2- pyridylazo) 2-naphthol) in the presence of buffer solution of pH 11 and 0.05 % (w/v) Triton X-114 as surfactant. The variables that affect the complex formation, extraction and separation of the phases, such as the concentration of complexing and surfactant agents, the effect of pH and volume of buffer solution were evaluated. An electrolyte solution of NaCl was used to conduce the point cloud formation without the need for heating. From the optimized conditions for determination of Cr(III), detection limit of 0.47 mg L-1, limit of quantification of 1.56 mg L-1 relative standard deviation (RSD) of 3.05 % for n = 10 and enrichment factor of 20.3 were obtained. The accuracy was proved by standard addition and recovery experiments, obtaining quantitative recoveries in the range 88-120%, and the method was applied to samples of mineral water.

Fundação de Amparo a Pesquisa do Estado de Minas Gerais

Fundação de Amparo a Pesquisa do Estado de Minas Gerais

Fundação de Amparo a Pesquisa do Estado de Minas Gerais

The Mancozeb is a fungicide belonging to the class of dithiocarbamates (DTCs) widely used in agriculture and non- systemic fungicide controlling a wide variety of fungi in crops of rice, potato, tomato, and citrus. Nowdays, the agrochemical industries quantify the content of Mancozeb in their commercial products using iodometric titration. The biggest drawback of this methodology is the analysis time (about two hours and thirty minutes), which causes downtime, hand labor and idle delays in approving the final product, creating problems in the flow of production and delays in delivery. This work presents the aplication electroanalytical method for the determination the fungicide Mancozeb in pesticides using boron-doped diamond electrode (BDD) and batch injection analysis (BIA) with amperometric detection. Studies regarding the choice of the electrolyte (phosphate solution pH 9.0) and potential applied (+0.3 V) were performed. And, the BIA system parameters such as injection rate and injected volume were optimized. Regarding the quantification of Mancozeb, an analytical curve with a detection limit of 5.14x10-7 mol L- 1 and limit of quantification 1.71x10-6 mol L- 1 was obtained. Interfering studies were performed and yielded recovery coefficients between 88.70 and 108.7 %. The content of mancozeb was determined in samples of pesticides with relative error lower than 1.85 %, another advantages associated to the developed method is high analytical frequency (90 injections per hour).

Fundação de Amparo a Pesquisa do Estado de Minas Gerais

Fundação de Amparo a Pesquisa do Estado de Minas Gerais

Fundação de Amparo a Pesquisa do Estado de Minas Gerais

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

Fundação de Amparo a Pesquisa do Estado de Minas Gerais

Fundação de Amparo a Pesquisa do Estado de Minas Gerais

Fundação de Amparo a Pesquisa do Estado de Minas Gerais

Fundação de Amparo a Pesquisa do Estado de Minas Gerais

Fundação de Amparo a Pesquisa do Estado de Minas Gerais

Fundação de Amparo a Pesquisa do Estado de Minas Gerais

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

Conselho Nacional de Desenvolvimento Científico e Tecnológico