Lisia Maria Gobbo dos Santos

Simultaneous determination of Cd and Fe in beans and soil of different regions of Brazil using high-resolution continuum source graphite furnace atomic absorption spectrometry and direct solid sampling.

A fast routine screening method for the simultaneous determination of cadmium and iron in bean and soil samples is proposed, using high-resolution continuum source graphite furnace atomic absorption spectrometry and direct solid sampling. The primary absorption line at 228.802 nm has been used for the determination of cadmium, and an adjacent secondary line, at 228.726 nm, for iron. Fourteen bean samples and 10 soil samples from nine states all over Brazil have been analyzed. The limits of detection (3 sigma, n = 10) were 2.0 microg kg(-1) for Cd and 4.5 mg kg(-1) for Fe. The relative standard deviation ranged from 4 to 7% for Cd and from 5 to 28% for Fe, which is usually acceptable for a screening method. The accuracy of the method has been confirmed by the analysis of two certified reference materials; the results were in agreement with the certified values at a 95% confidence interval.

Comparison of the nutritional and toxicological reference values of trace elements in edible marine fish species consumed by the population in Rio De Janeiro State, Brazil

The present study estimated the human daily and weekly intake of inorganic elements due to consumption of fish in Rio de Janeiro state and the associated potential health risks posed by some toxic elements. All samples analyzed had values of Cd and Pb below the Maximum Tolerable Limits of 3.0 mg kg−1 for Pb and 1.0 mg kg−1 for Cd; only Mugil cephalus, Cynoscion leiarchus and Caranx crysos had As concentrations below 1 mg kg−1, maximum limit established by Brazilian legislation. The higher values of Cd and Pb correspond to 0.22% of PTWI and the higher value of As corresponds to 8.6% of PTWI. None of the studied species showed values higher than PTWI. The higher values of Cu EDI found in Pomatomus numida correspond to 33.3% of RDA; Fe in Salmo salar and Genypterus brasiliensis corresponds to 4.3% of EDI; Mn in Sardinella brasiliensis corresponds to 7.4% of EDI; Zn in S. salar corresponds to 13.2% of EDI and Se in S. salar corresponds to 20.6% of EDI. Some species can be a good source of inorganic elements. For risk assessment, it is important to assess specific eating habits of each region to avoid underestimating the data.

Determinação simultânea de As, Cd e Pb em amostras de água purificada para hemodiálise por espectrometria de absorção atômica com forno de grafite, após otimização multivariada baseada no uso de planejamento experimental

This paper reports the development of a methodology for simultaneously determining As, Cd and Pb, employing GF AAS with polarized Zeeman-effect background correction. In order to make the procedure applicable, the influence of pyrolysis and atomization temperatures and the amount of chemical modifiers were studied. Factorial and central composite designs were used to optimize these variables. Precision and accuracy of the method were investigated using Natural Water Reference material, Nist SRM 1640. Results are in agreement with certified values at the 95% confidence limit when the Student t-test is used. This methodology was used for quality control of purified water for hemodialysis.

Optimization and validation of a methodology to determine total arsenic, As(III) and As(V), in water samples, through graphite furnace atomic absorption spectrometry

A tecnica de espectrometria de absorcao atomica com forno de grafite (GF AAS) foi a tecnica escolhida pelo laboratorio de contaminantes inorgânicos do Instituto Nacional de Controle de Qualidade em Saude (INCQS/FIOCRUZ) para ser validada e aplicada em analises de rotina para deteccao e quantificacao de arsenio. Os parâmetros de validacao seletividade, linearidade, sensibilidade, limite de deteccao e quantificacao, exatidao e precisao foram estudados e otimizados usando as condicoes STPF (Stabilized Temperature Platform Furnace). Os resultados encontrados apresentaram limites de deteccao 0,13 µg.L-1 e quantificacao de 1,04 µg.L-1, uma precisao media para arsenio total inferior a 15% e uma exatidao de 96%. Para quantificar as especies quimicas As(III) e As(V), utilizamos uma resina de troca ionica (Dowex 1X8, forma de Cl-) e os parâmetros fisico-quimicos foram otimizados, obtendo-se uma recuperacao de As(III) de 98% e de As(V) de 90%. O metodo foi aplicado em amostras de aguas subterrâneas, aguas minerais e agua purificada para hemodialise. Todas as amostras apresentaram resultados abaixo do limite maximo permitido pelas legislacoes em vigor: 50 µg.L-1, 10 µg.L-1 e 5 µg.L-1, respectivamente. Todos os resultados foram avaliados estatisticamente.

Avaliação das Impurezas Elementares do Medicamento Captopril Comercializadas na Cidade do Rio de Janeiro, Brasil

Resumo: O objetivo desse trabalho foi otimizar e validar metodologia analitica para determinar impurezas elementares em IFAs e produto final de captopril, tendo como base as novas diretrizes da Farmacopeia Americana. As tecnicas escolhidas para este fim foram a espectrometria atomica de emissao optica de plasma acoplada indutivamente e a espectrometria de absorcao atomica do forno de grafite. Os resultados indicam que a tecnica desenvolvida foi capaz de atender as necessidades desejadas. Todas as amostras analisadas apresentaram resultados satisfatorios em relacao aos limites maximos permitidos pela USP.