Descreve-se a validação de um método para a determinação de manganês, molibdênio e zinco a níveis-traço, em soluções aquosas, por Espectrometria de emissão por plasma acoplado indutivamente de argônio. Foi maximizada e validada a quantificação de manganês, molibdênio e zinco em solução aquosa ácida, utilizando um espectrômetro de emissão atômica por plasma acoplado indutivamente. Foram determinados: seletividade/especificidade, linearidade, repetibilidade e precisão intermediária usando materiais de referência, e viés contrastando contra material de referência certificado de matriz. Os comprimentos de onda (nm) selecionados foram: Zn 213.857; Mn 257.610 e Mo 202.031, os quais permitiram discriminar interferências espectrais. A linearidade das funções resposta foi provada por avaliações estatísticas ad hoc. A precisão intermediária variou entre 5 e 11% e o viés não ultrapassou 12%. Os limites de quantificação (μg/L) foram: Mn: 5; Zn: 10 e Mo: 10. As incertezas associadas com as determinações variaram entre 10 e 16%. A validação do método proposto demonstrou que é seletivo, proporciona incertezas adequadas e é útil para quantificar com rapidez e precisão os metais-traço estudados em matrizes que podem ser levadas a solução aquosa, prévia digestão em meio ácido.

A method to accurately determine and quantify manganese, molybdenum and zinc using Optical Emission Spectroscopy-Inductively Coupled Plasma by optical emission spectrometer was optimized and validated. Selectivity/ specificity, linearity, repeatability, intermediate precision and bias using reference materials and certified matrix reference material, respectively, were determined. Selected wavelengths (nm) Zn 213.857; Mn 257.610 and Mo 202.031 made it possible to discriminate spectral interferences. Linearity was proved by ad hoc statistical evaluations. Intermediate precision ranged between 5 and 11% and bias was never greater than 12%. Quantification limits (mg/L) were: Mn: 5; Zn: 10 y Mo: 10. Uncertainties associated to analytical determinations ranged between 10% and 16%. The validation of the proposed method demonstrated that it is selective, it provides adequate uncertainties and it is useful to quantify quickly and accurately the studied trace metals in matrices that can be taken intoaqueous solution with prior digestion in acid medium.

Se describe la validación de un método para la determinación de manganeso, molibdeno y zinc, a niveles traza, en soluciones acuosas, mediante espectroscopia de emisión-plasma inductivo de argón. Se optimizó y validó la cuantificación de manganeso, molibdeno y zinc en solución acuosa ácida usando un espectrómetro de emisión atómica de plasma inductivo. Se determinaron: selectividad/especificidad, linealidad, repetibilidad y precisión intermedia utilizando materiales de referencia, y sesgo contrastando contra material de referencia certificado de matriz. Las longitudes de onda (nm) seleccionadas fueron: Zn 213.857, Mn 257.610 y Mo 202.031, las cuales permitieron discriminar interferencias espectrales. Se probó la linealidad de las funciones respuesta mediante evaluaciones estadísticas ad hoc. La precisión intermedia varió entre 5 y 11% y el sesgo no superó el 12%. Los límites de cuantificación (μg/L) fueron: Mn: 5; Zn: 10 y Mo: 10. Las incertidumbres asociadas a las determinaciones oscilaron entre 10 y 16%. La validación del método propuesto demostró que es selectivo, proporciona incertidumbres adecuadas y es de utilidad para cuantificar de manera rápida y certera los metales traza estudiados en matrices que puedan ser llevadas a solución acuosa, previa digestión en medio ácido.

Artisanal harvesting of bivalve molluscs, known as shellfishing, is an important source of food and economic resources to social groups that live in Patagonian coastal populations. It has also become an important alternative for mariculture in San Jorge Gulf. The aim of this study was to determine the concentrations of Ca, Mg, P, Cr, Cu, Fe, Mn, Mo, Se and Zn in Mytilus edulis platensis from three sites in San Jorge Gulf, in order to evaluate the geographical and seasonal variation of these items, and determine their nutritional contribution. The sampling sites were focused on two places without anthropic activity; Bahía Solano and Punta Maqueda, and a third place was one with anthropogenic activity: Playa Km 3. The samples were digested via wet way using Parr bombs. The elements were quantified via inductively coupled plasma-optical emission spectrometry (ICP-OES). The results were expressed in cover percentages considering the annual average of each item studied. In this way, according to the Dietary Reference Intakes, the consumption of 100 grams of fresh mussel would cover adult women´s (W) and men´s (M) needs, in the following percentages: 26% of Ca (W and M), 42% (W) and 35% (M) of Mg,18% of P (W and M), 176% (W) and 126% (M) of Cr, 11% of Cu (W and M), 34% (W) and 70% (M) of Fe, 17% (W) and 13% (M) of Mn, 26% of Mo (W and M), 202% (W) and 155% (M) of Se, and 30% (W) and 21% (M) of Zn. A conclusion is that 100 g of mussels provide essential elements at considerable levels, subjected to a geographical and seasonal variation, a fact that should be considered in order to expand and improve the information currently found in food composition tables. The results obtained provide valuable information, considering they come from the Patagonian coast, and that this food is usually consumed in our country.

La recolección artesanal de moluscos bivalvos, actividad conocida como marisqueo, es una significativa fuente alimenticia y económica para grupos sociales de poblaciones costeras patagónicas. Además, se ha constituido como una importante alternativa de maricultura en la costa patagónica. El objetivo de este trabajo fue determinar las concentraciones de Ca, Mg, P, Cr, Cu, Fe, Mn, Mo, Se y Zn en Mytilus edulis platensis de tres sitios de la costa del Golfo San Jorge, a fin de evaluar la variación geográfica y estacional de estos elementos y determinar su contribución nutricional. Los lugares de muestreo se centraron en dos sitios alejados de la actividad antrópica, Bahía Solano y Punta Maqueda, y un tercer sitio Playa Km 3, con actividad antropogénica. Las muestras fueron digeridas por vía húmeda con Bombas Parr. Los elementos fueron cuantificados mediante un espectrómetro de plasma inductivo (ICP-OES). Los resultados fueron expresados como porcentajes de cobertura considerando el promedio anual de cada elemento estudiado. En este sentido, según las Ingestas Dietéticas de Referencia, el consumo de 100 gramos de moluscos frescos cubrirían las necesidades para mujeres (M) y hombres (H) adultos en los siguientes porcentajes: Ca 26% (M y H), Mg 42% (M) y 35% (H), P 18% (M y H), Cr 176% (M) y 126% (H), Cu 11% (M y H), Fe 34% (M) y 70% (H), Mn 17% (M) y 13% (H), Mo 26% (M y H), Se 202% (M) y 155% (H) y Zn 30% (M) y 21% (H). Es posible concluir que 100 g de mejillones aportan elementos indispensables en niveles considerables, sujetos a variación temporal y geográfica, hecho que debería ser tenido en cuenta para ampliar y mejorar la información actualmente reflejada en tablas de composición de alimentos. Los resultados obtenidos proporcionan información de gran valor, dado que corresponden a un alimento originario de la costa Patagónica y consumido de forma habitual en nuestro país.

Resumen Las uropatías constituyen una causa frecuente de insuficiencia renal crónica (IRC) en el niño. El reflujo vesicoureteral (RVU) está presente en el 18-50% de los niños evaluados por su primera infección urinaria (IU). La indicación tradicional de la cistouretrografía retrógrada miccional (CUGM) luego de 3-6 semanas de la primera IU tiene el riesgo de pérdida de seguimiento de los pacientes y el no cumplimiento de la indicación médica en la realización del estudio como ha sido documentado internacionalmente y en nuestro medio. El objetivo de este trabajo es evaluar los resultados de la CUGM precoz en pacientes hospitalizados por IU en un servicio de pediatría y compararlos con los de la CUGM tardía. Se realizó un estudio descriptivo prospectivo en pacientes hospitalizados por IU sin CUGM previa. De 63 pacientes se logró la realización de la CUGM en 56: 88,8%. El 73% fueron de sexo femenino, el 87,4% menores de dos años. El 93% fueron IU febriles, 48% presentaron manifestaciones digestivas y 21,4% síntomas de la esfera nefrourológica. Los urocultivos presentaron Escherichia coli en 91% de los casos. En 33 pacientes la CUGM se realizó antes de los 7 días del diagnóstico de IU (59%): cistografía precoz. En 23 (41%) luego de los siete días: cistografia tardía. Se detectó RVU en 15 pacientes (27%). La edad promedia del diagnóstico del RVU fue de 21 meses. No se demostraron diferencias significativas entre ambos grupos respecto a la incidencia de RVU. La comparación del grupo de CUGM precoz con el gupo del trabajo inicial en que se efectuó la CUGM a 27/60 pacientes luego de tres semanas del diagnóstico de IU tampoco mostró diferencias significativas. La distribución de los grados de RVU fue similar en los tres grupos. Conclusiones: la CUGM precoz no presentó complicaciones y permitió evaluar la existencia de RVU en un alto porcentaje de pacientes. No se sobrediagnosticó RVU en esta población. El diagnóstico de RVU se realizó tardíamente lo que obliga a proseguir en la alerta diagnóstica de IU y su estudio a nivel de atención primaria.

Summary Uropathies are a frequent etiology of chronic renal failure(CRF) in children. Vesicoureteral reflux (VUR) is detected in 18-50% of children studied during the first urinary tract infection (UTI). Many authorities recommend an interval of 3-6 weeks after a UTI before performing a voiding cystourethrogram (VCUG). However such an interval may reduce the likelihood of completing the procedure as has been documented in different papers of many countries and in our own. This study was performed to evaluate the results of the VCUG done before the first week of the diagnosis of the UTI and compare them with those investigated later. In the period of the study 63 patients were admitted with the diagnosis of UTI. VCUG was performed in 56:88,8%. 73,2% were females, 87,4% were less than 2 years of age. Fever was present in 93 %, gastrointestinal symptoms in 48%, nephrourological manifestations in 21,4%. Escherichia coli was obtained in 91% of the cultures. In 33 patients (59%), VCUG was performed before the first week of diagnosis (early group). In 23 (41%) after the first week (late group). VUR was detected in 11 patients (33%) of the early group and 4 (17,3%) of the late group (p 0,2). There was not significant difference. The comparison of the early group with another one in which all the VCUG were performed after 3 weeks of the diagnosis of UTI 27/60 didn’t showed significant differences either (p: 1). Conclusions: early VCUG didn’t present complications and allowed to evaluate the existence of VUR in a high number of patients. Diagnosis of VUR in the early VCUG is not significantly different from those studied later. Diagnosis of VUR is done late. It is necessary to alert primary attention pediatricians in the adequate diagnosis of UTI and the importance of doing VCUG in these cases.

A técnica de amostragem de suspensão aliada à espectrometria de absorção atômica com chama foi empregada para a determinação direta de Cu, Fe, Mn e Zn em matrizes de Krill antártico. O efeito dos parâmetros instrumentais e o preparo das suspensões foram estudados em função do sinal analítico. Para a determinação de Cu, Fe e Zn, as amostras foram suspensas em uma solução de HNO3 2,0 mol L-1 e para a determinação de Mn, o krill foi suspenso em uma solução de HNO3 4,0 mol L-1. A precisão entre as replicas foi melhor que 5 %. A metodologia foi aplicada para a determi-nação direta de Cu, Fe, Mn e Zn em amostras de krill antártico, usando padrões aquosos no preparo das curvas analíticas. Os resultados obtidos estão concordantes com os encontrados na determinação por FAAS e ICP-AES, depois da digestão das amostras em um forno de microondas. Os limites de detecção foram 4,5; 1,0; 4,9 e 8,4 mig L-1 para Cu, Zn, Mn e Fe, respectivamente.

Slurry sampling in combination with flame atomic absorption spectrometry was employed for the direct determination of four essential trace elements, namely Cu, Fe, Mn and Zn in Antarctic krill. The effect of instrumental operating conditions and slurry sampling preparation on the analytical signal was investigated. For the determination of Cu, Fe and Zn, samples were suspended in a solution containing 2 mol L-1 HNO3. In the case of Mn, 4 mol L-1 HNO3 was necessary for the preparation of the slurry. The precision between sample replicates was better than 5%. The method was applied to the direct determination of Cu, Fe, Mn and Zn in Antarctic krill samples using aqueous reference solutions to prepare the calibration curves. The results obtained were in good agreement with those achieved by FAAS and ICP-AES after microwave-assisted wet digestion of the krill samples. The detection limits were 4.5, 1.0, 4.9 and 8.4 mug L-1 for Cu, Zn, Mn and Fe, respectively.