Peat as a natural solid-phase for copper preconcentration and determination in a multicommuted flow system coupled to flame atomic absorption spectrometry.

The physical and chemical characteristics of peat were assessed through measurement of pH, percentage of organic matter, cationic exchange capacity (CEC), elemental analysis, infrared spectroscopy and quantitative analysis of metals by ICP OES. Despite the material showed to be very acid in view of the percentage of organic matter, its CEC was significant, showing potential for retention of metal ions. This characteristic was exploited by coupling a peat mini-column to a flow system based on the multicommutation approach for the in-line copper concentration prior to flame atomic absorption spectrometric determination. Cu(II) ions were adsorbed at pH 4.5 and eluted with 0.50 molL(-1) HNO(3). The influence of chemical and hydrodynamic parameters, such as sample pH, buffer concentration, eluent type and concentration, sample flow-rate and preconcentration time were investigated. Under the optimized conditions, a linear response was observed between 16 and 100 microgL(-1), with a detection limit estimated as 3 microgL(-1) at the 99.7% confidence level and an enrichment factor of 16. The relative standard deviation was estimated as 3.3% (n=20). The mini-column was used for at least 100 sampling cycles without significant variation in the analytical response. Recoveries from copper spiked to lake water or groundwater as well as concentrates used in hemodialysis were in the 97.3-111% range. The results obtained for copper determination in these samples agreed with those achieved by graphite furnace atomic absorption spectrometry (GFAAS) at the 95% confidence level.

Intoxicação por enrofloxacina em um cão da raça Pinscher Miniatura: relato de caso / Enrofloxacin poisoning in a Miniature Pinscher: a case report

Uma cadela da raça Pinscher Miniatura foi medicada pelo proprietário com enrofloxacina, na dose de 50mg/kg, uma vez ao dia, por dois dias (dose diária 10 vezes maior que a prescrita). Ao exame clínico o animal apresentou-se deprimido, em cifose lombar, hipotérmico, com mucosas pálidas, dispnéia, sialorréia, vômitos e anúria, evoluindo para parada respiratória, convulsões e coma. Foi realizado tratamento sintomático. O fluxo urinário retornou ao normal em 12 horas e as convulsões foram controladas, mas o animal permaneceu em coma, morrendo 72 horas após o início do tratamento. A necropsia e o histopatológico confirmaram insuficiência renal e hepática agudas, e choque hipovolêmico, compatível com intoxicação por enrofloxacina.

A Miniature Pinscher bitch was treated by the owner with enrofloxacin at dose of 50 mg/kg, once a day, for two days (daily dose rate 10 times greater than prescribed). Physical examination showed depression, lumbar cifosis, hipotermia, pale mucosa, dispneia, drewling, vomiting and anuria, followed by respiratory failure, seizures, and coma. Symptomatic treatment was performed, and the urinary flow returned to normal in 12 hours, and seizures were controlled. However, the animal stayed in coma, and died 72 hours after the beginning of the treatment. Acute renal and hepatic failure, and hipovolemic shock, compatible with enrofloxacin intoxication, were observed through necropsia and histopatology.

Production of monoclonal antibodies against conserved components of infectious bronchitis virus

Murine hybridomas producing IgG1 monoclonal antibodies (Mabs) against N and S2 (subscript) proteins (53KDa and 82 KDa, respectively) from avian infection bronchitis virus (IBV) strain M41 were generated by the fusion of a myeloma cell line (Sp2/0-Ag14) with spleen cells from Balb/c mice previously immunized with whole virus IBV M41. Post-fusion screening criterion was by ELISA and 36 positive hybrids were generated after fusions. Two hybrids specific to N (N3F10) and S2 (subscript) (S12B2) proteins from M41 (serotype Massachusetts) were selected by western blotting. These Mabs recognized the Ark-99 (serotype Arkansas) and A5968 (serotype Connecticut) IBV strains in addition to M41. By ELISA, the Mab against the S2 (subscript) (S12B2) recognized all reference and Brazilian strains (M41, SE-17, H52, 297, 283, PM-1, PM-2, PM-3, 351, 29-78 E 327) studied, while the Mab against N recognized only six (M41, SE-17, H52, 283, 327 e 297) strains. The Mab against S2 (subscript) may become a useful tool for IBV detection on the routine diagnosis of infectious bronchitis, especially for helping the differential diagnosis of clinically and pathologically confusing diseases, while the Mab against N (N3F10) recognized a probably less conserved region among the strains and may be interesting to comparing IBV isolates

Flow-injection spectrophotometric multidetermination of metallic ions with a single reagent exploiting multicommutation and multidetection.

A flow system designed by computer-controlled discrete commutation devices is proposed for the multidetermination of metallic ions with a single chromogenic reagent. Intermittent addition of masking agents and changes of the reaction pH were exploited to implement selective determination of four species. Multidetection with an optical-fiber CCD-array spectrophotometer enabled simultaneous measurements at different wavelengths for multidetermination. The proposed system was applied to the determination of iron, copper, nickel and zinc in alloys and pharmaceutical preparations, yielding results in agreement with those obtained by flame atomic absorption spectrophotometry at the 95% confidence level. The sampling rate was estimated to be 80 determinations per hour. Coefficients of variation lower than 2% (n = 20) were achieved for all species.

A multicommutation-based flow system for multi-element analysis in pharmaceutical preparations.

A flow system exploiting multicommutation and multidetection is proposed for sequential determinations in pharmaceutical preparations. The feasibilities were demonstrated by the determination of zinc, iron, copper, calcium and magnesium without changing the flow set-up. The gravitational flow of the solutions was exploited for addition of different chromogenic reagents and sample aliquots, thus avoiding the use of a propulsion unit. Transient signals at different wavelengths were measured simultaneously employing a fiber-optic multichannel spectrophotometer. Coefficients of variation of 1.0, 1.5, 1.4, 2.5 and 2.0% were obtained for iron, zinc, copper, calcium and magnesium, respectively. The mean sampling rate for the five species was 60 determinations per hour. In comparison to continuous reagent addition systems, the consumption was up to 160-fold lower. Results for pharmaceutical preparations agreed with those obtained by Flame atomic absorption spectrophotometry (FAAS) at the 95% confidence level.

Influences of handedness and gender on the grooved pegboard test.

We studied performance on the Grooved Pegboard Test upon repeated trials and transfer of training between the hands in the first trial. The classification of handedness was based on the writing hand. We employed three trials for each hand and two different protocols for the order in which the hands started the test. For the three trials combined, women were faster than men. From the first to the second trial, there was an improvement in performance for both sexes. Within the first trial, sex differences reached significance and the protocol interacted with handedness. In this trial, only left-handed men were found to benefit from previous opposite-hand performance. It is speculated that a larger corpus callosum in left-handed men allows for the greater transfer of training between the hands.

Nickel and zinc determination by flow-injection solid-phase spectrophotometry exploiting different sorption rates.

Flow-injection solid-phase spectrophotometry is applied for sequential determination of nickel and zinc, exploiting their different sorption rates on 1-(2-thiazolylazo)-2-naphthol (TAN) immobilized on C(18)-bonded silica. The Zn(II) sorption rate on the solid support is constant for flow rates ranging from 0.70 to 2.2 ml min(-1), but for Ni(II) the sorption rate decreases with increasing flow rate. A flow system was designed to perform sequential measurements at two different flow rates (0.85 and 1.9 ml min(-1)). The absorbance was measured at 595 nm, where both TAN-immobilized complexes showed maximum absorption. The coefficients of variation were estimated (n=10) as 1.1 and 1.7% (at 1.9 ml min(-1)) and 1.2 and 2.1% (at 0.85 ml min(-1)) for zinc and nickel, respectively. This strategy was applied to determine zinc and nickel in copper-based alloys and the results agreed with certified values at the 95% confidence level. The sample throughput was estimated as 36 h(-1).

Milheto-grão (Pennisetum glaucum (L.) R.Br.) como substituto do milho em rações para poedeiras comerciais

The production performance and egg quality of laying hens receiving increasing levels of pearl millet grain in rations were studied. Two hundred 30-week-old LSL Lohmann white hens, allotted in a completely randomized design with five treatments, five replicates with 10 hens, were fed with 0, 25, 50, 75 and 100% of pearl millet grain in rations as corn substitute. The performance was evaluated by egg production, feed intake, feed conversion in terms of dozen eggs and egg mass, and egg quality measured as egg weight, shell, albumen and yolk porcentages. No differences among treatments were observed for all characteristics, but the yolk color index measured by the Roche fan indicated decreasing in yolk colour as the level of pearl millet increased. Pearl millet did not affect the production performance, and a synthetic or natural pigment should be included in rations.

Avaliaram-se o desempenho produtivo e a qualidade dos ovos de poedeiras comerciais alimentadas com milheto como substituto do milho em rações de postura. Duzentas poedeiras comerciais, da linhagem LSL Lohmann branca, com 30 semanas de idade, receberam rações com níveis crescentes de substituição da energia metabolizável fornecida pelo milho por milheto. As aves foram distribuídas em um delineamento inteiramente ao acaso com cinco tratamentos, cinco repetições e 10 aves por repetição. Foram avaliados a porcentagem de postura, o consumo de ração, a conversão alimentar em termos de dúzias e de massa de ovos, o peso médio de ovos, a porcentagem de casca e de gema, e a porcentagem de clara. Não se observou diferença estatística significativa em todas as características. O índice de coloração de gema, pelo leque colorimétrico Roche, apresentou pior coloração à medida que os níveis de milheto foram crescentes nas rações. Os resultados indicam que o milheto não afetou o desempenho produtivo das aves, devendo-se recomendar o seu uso com pigmentantes sintéticos ou naturais.

Milheto-gräo (Pennisetum glaucum (L.) R.Br.) como substituto do milho em raçöes para poedeiras comerciais / Pearl millet grain as corn substitute in laying hen rations

Avaliaram-se o desempenho produtivo e a qualidade dos ovos de poedeiras comerciais alimentadas com milheto como substituto do milho em raçöes de postura. Duzentas poedeiras comerciais, da linhagem LSL Lohmann branca, com 30 semanas de idade, receberam raçöes com níveis crescentes de substituiçäo da energia metabolizável fornecida pelo milho por milheto. As aves foram distribuídas em um delineamento inteiramente ao acaso com cinco tratamentos, cinco repetiçöes e 10 aves por repetiçäo. Foram avaliados a porcentagem de postura, o consumo de raçäo, a conversäo alimentar em termos de dúzias e de massa de ovos, o peso médio de ovos, a porcentagem de casca e de gema, e a porcentagem de clara. Näo se observou diferença estatística significativa em todas as características. O índice de coloraçäo de gema, pelo leque colorimétrico Roche, apresentou pior coloraçäo à medida que os níveis de milheto foram crescentes nas raçöes. Os resultados indicam que o milheto näo afetou o desempenho produtivo das aves, devendo-se recomendar o seu uso com pigmentantes sintéticos ou naturais

Flow injection spectrophotometric determination of nitrate in electrolyte of lead-acid batteries.

Electrolytes of lead-acid batteries can contain several impurities that reduce battery performance and lifetime. Nitrate ions are among these species because they can be reduced to ammonium in the lead electrode. In this work, an analytical method was developed to determine this anion in electrolytes of batteries used in telephone systems, in which nitrate concentration must be lower than 10 mg l(-1). The procedure consists in the reduction to nitrite in a copperized cadmium column followed by Griess's modified reaction. Due to the high sensitivity of this methodology, a large dispersion flow diagram (dispersion coefficient = 27.8) was projected. Thus, it was possible to eliminate the Schlieren effect and to obtain a NH (3)NH (+)(4) buffer in the sample zone in a suitable pH for reduction reaction (pH congruent with 8). Negative interference due to iron(III) was overcome by addition of excess iron (200 mg l(-1)). A relocatable filter was used to remove iron(III) hydroxide precipitate. This avoided adsorption on the surface of the filings and increase of back pressure. The analytical frequency is 80 measurements/h and the detection limit was estimated as 0.3 mg l(-1) in a 99.7% confidence level. A 2.2% relative standard deviation was obtained in a repeatability study (n = 10) by using a 25 mg l(-1) nitrate solution in a 3.6 mol l(-1) sulfuric acid medium. Recoveries from 95.5 to 104% were obtained by spiking 5.00 or 10.0 mg l(-1) of nitrate in samples of battery electrolyte.