Spectrophotometric determination of creatinine by monosegmented continuous-flow analysis

A monosegmented continuous-flow system (MCFS) has been evaluated for determination of creatinine in urine using the Jaffé reaction. The analyser is compact and allows 130 determinations to be performed per hour, with a relative standard deviation of the peak height better than 1.5% (N =10). The results for real samples agree with those obtained by. the standard manual Jaffé procedure and with the kinetic automatic method

Operator-free flow injection analyser

A flow injection analyser has been constructed to allow an operator-free determination of up to 40 samples. Besides the usual FIA apparatus, the analyser includes a home-made sample introduction device made with three electromechanical three-way valves and an auto-sampler from Technicon which has been adapted to be commanded by an external digital signal. The analyser is controlled by a single board SDK-8085 microcomputer. The necessary interface to couple the analyser components to the microcomputer is also described. The analyser was evaluated for a Cr(VI)-FIA determination showing a very good performance with a relative standard deviation for 15 signals from the injection of 100 μl of a 1.0 mg.ml-1 standard Cr(VI) solution being equal to 0.5%

Adaptation of a cold vapour mercury analyser to flow injection analysis

Minor modifications to a Coleman MAS-50A Mercury Analyser System allowed the determination of mercury by flow injection analysis. Using sample volumes of 600 μl it was possible to analyse up to 120 samples per hour, with a detection limit of 0.2 μg. l-1 (120 pg) of mercury. The authors also report on a simple digestion procedure which replaces the time- and reagent-consuming EPA procedure, when the sample content permits

Studies on the bioavailability of zinc in rats supplementated with two different zinc-methionine compounds

Se han estudiado los efectos de los complejos zinc-metionina con la relación molar 1:1 y 1:2 como suplementación alimentaria de zinc en ratones. La obtención y la caracterización de dos complejos de zinc fueron evaluadas por análisis elemental y FTIR. El efecto de la biodisponibilidad de zinc fue estudiado por la retención en el contenido del metal en los tejidos de ratones alimentados con diversas fuentes. El compuesto 1:1 era un complejo del catión de fórmula [Zn(C5H10NO2S)(H2O)2]+ , muy soluble en agua, mientras que el compuesto 1:2 era un complejo neutro de fórmula [Zn(C5H10NO2S)2], solamente soluble debajo de pH 3. Los espectros de FTIR de ambos complejos demostraron franjas de absorción fuertes debido al estiramiento del C-O del grupo del aminoácido (extendiéndose de νs(C=O) 1638 cm–1 y νas(C-O) 1414 cm–1 , en ZnMet, a νs(C=O) 1608 cm–1 y νas(C-O) 1426 cm–1 , en Zn(Met)2, cambiados de posición perceptiblemente las frecuencias asimétricas aumentan y las frecuencias simétricas disminuyen con respecto a la metionina libre νs(COO) 1582 cm–1 y νas(COO) 1415 cm–1 , 1720 cm–1 El resultado de la alimentación fue observado claramente en la eliminación fecal del zinc de los animales del grupo de control perceptiblemente diferente (P < 0,05) que los tratados de los . animales con dietas suplementadas con zinc, pero no se observó en la eliminación urinaria. El estudio indica que el contenido del zinc en las heces recogidas en 14 días para toda la dieta del zinc era perceptiblemente diferente (P < 0,05) del grupo de control (tratamiento de los animales con prácticamente ausencia de zinc). La retención del zinc en los grupos a los que se administraron compuestos de metionina fue perceptiblemente más alta que la alimentación con dieta de ZnSO4 y de ZnO. En conclusión, estos datos indican que el uso del los complejos zincmetionina constituyen una herramienta valiosa a la biodisponibilidad del aumento del zinc, no obstante sin diferencias significativas entre ZnMet y la forma Zn(Met)2.The effects of zinc-methionine complexes with molar relation 1:1 and 1:2 have been examined as nutritional supplements in rats. The synthesis and characterization of two compounds were studied by elemental analysis and FTIR. The bioavailability effect was studied by zinc retention and its content in rat tissues in rats fed with different zinc-methionine complexes. The compound 1:1 was a cation complex of formula [Zn(C5H10NO2S)(H2O)2]+ , very water soluble, while the compound 1:2 was a neutral complex of formule [Zn(C5H10NO2S]2], only soluble in pH below 3. FTIR spectra of both complexes show strong absorption bands due to C-O stretching of the amino acid group (ranging from νs(C=O) 1638 cm–1 and νas(C-O) 1414 cm–1 , in ZnMet, to νs(C=O) 1608 cm–1 and νas(C-O) 1426 cm–1 , in Zn(Met)2) shifted significantly with respect to the ones observed for the free methionine (νas(COO) 1582 cm–1 and νs(COO) 1415 cm–1 ,1720 cm–1 ). The nutritional result in the zinc fecal elimination of the animals of the control group was significantly different (P < 0.05) to the ones observed for the animals treaties with zinc supplemented diets, though this was not observed during urinary elimination. This study indicates that the content of zinc in the feces collected in 14 days for all zinc diet were significantly different (P<0.05) from the control group (animals treaties with zinc practically absent). The retention of zinc in the groups treated with the methionine compounds was significantly higher than the ones fed with ZnSO4 and ZnO diet. In conclusion, these data indicate that the use of zinc-methionine chelates is a valuable tool to increase bioavailability of zinc, however without significant differences between ZnMet and Zn(Met)2.Colegio de Farmacéuticos de la Provincia de Buenos Aire

O direito fundamental ao trabalho decente sob a ótica da erradicação do trabalho infantil e proteção do adolescente.

O texto aborda o trabalho decente como direito fundamental, com ênfase na situação juvenil, na medida em que pontua a necessidade de erradicação do trabalho infantil como forma de alcança-lo, aliado à medidas de proteção dos adolescentes no mercado de trabalho.The issue of child labor is a matter of concern worldwide, especially in view of its harmful consequences, particularly as regards the perpetuation of the cycle of poverty and school drop-out