Preparação de amostra de fígado bovino e estudo de micro homogeneidade para a determinação de Cd E Pb por espectrometria de absorção atômica com atomização eletrotérmica e amostragem direta de sólido
Abstract:Recebido em 27/1/05; aceito em 3/8/05; publicado na web em 20/1/06 BOVINE LIVER SAMPLE PREPARATION AND MICRO-HOMOGENEITY STUDY FOR Cd AND Pb DETERMINATION BY SOLID SAMPLING ELECTROTHERMAL ATOMIC ABSORPTION SPECTROMETRY. This work describes a systematic study for bovine liver sample preparation for Cd and Pb determination by solid sampling electrothermal atomic absorption spectrometry. Samples were prepared using different procedures: (1) drying in a household microwave oven followed by drying in a stove at 60 … Show more
“…For the determination of lead concentrations in tissues, the samples were prepared according to the protocol described by Nomura & Oliveira (2006). Thereafter, the samples were digested in acid (concentrated nitric acid) in a microwave oven (Multiwave 3000 -Anton Paar), and lead concentration determination was performed by high-resolution atomic absorption spectrometry (Analytik Jena) with atomization in an air-acetylene flame at the Laboratory of Environmental Survey and Analysis, Veterinary Sciences Center/Santa Catarina State University (Universidade do Estado de Santa Catarina -UDESC).…”
The present study describes the occurrence of lead poisoning in cattle and chickens in Pará, Brazil. In a lot composed of 80 calves from a dairy herd, 10 animals became sick and nine died, but one animal recovered after being removed from the paddock. Upon inspection of this paddock, the presence of truck batteries used to store energy captured by solar panels was found. The clinical signs observed in calves included difficult breathing, nasal discharge, excessive salivation, corneal opacity, pushing of the head against objects and recumbency. The chickens had decreased oviposition and produced eggs with thin or malformed shells. The necropsy findings of the cattle, as well as the histopathological changes observed, were of little significance except for one animal that showed mild astrocytosis histopathology in the cerebral cortex. In one of the chickens, renal histopathology showed mild multifocal acute tubular necrosis. The mean lead concentrations in the livers and kidneys of the cattle were 93.91mg/kg and 209.76mg/kg, respectively, and the mean concentration detected in chicken livers was 105.02mg/kg. It was concluded that the source of lead poisoning in these calves and chickens were the truck battery plates, which were within reach of the animals.
“…For the determination of lead concentrations in tissues, the samples were prepared according to the protocol described by Nomura & Oliveira (2006). Thereafter, the samples were digested in acid (concentrated nitric acid) in a microwave oven (Multiwave 3000 -Anton Paar), and lead concentration determination was performed by high-resolution atomic absorption spectrometry (Analytik Jena) with atomization in an air-acetylene flame at the Laboratory of Environmental Survey and Analysis, Veterinary Sciences Center/Santa Catarina State University (Universidade do Estado de Santa Catarina -UDESC).…”
The present study describes the occurrence of lead poisoning in cattle and chickens in Pará, Brazil. In a lot composed of 80 calves from a dairy herd, 10 animals became sick and nine died, but one animal recovered after being removed from the paddock. Upon inspection of this paddock, the presence of truck batteries used to store energy captured by solar panels was found. The clinical signs observed in calves included difficult breathing, nasal discharge, excessive salivation, corneal opacity, pushing of the head against objects and recumbency. The chickens had decreased oviposition and produced eggs with thin or malformed shells. The necropsy findings of the cattle, as well as the histopathological changes observed, were of little significance except for one animal that showed mild astrocytosis histopathology in the cerebral cortex. In one of the chickens, renal histopathology showed mild multifocal acute tubular necrosis. The mean lead concentrations in the livers and kidneys of the cattle were 93.91mg/kg and 209.76mg/kg, respectively, and the mean concentration detected in chicken livers was 105.02mg/kg. It was concluded that the source of lead poisoning in these calves and chickens were the truck battery plates, which were within reach of the animals.
“…24 Since then, there have been numerous reports about the effectiveness of this modifier. In practice, a mixture of palladium and magnesium has been shown to be an effective modifier for the determination of lead and cadmium in samples and reference materials of meat and fish slurries, 16,[25][26][27][28][29][30] the extent of its stabilization is highly reproducible. In this work, the Pd/Mg modifier has been applied with the addition of Triton X-100 as dispersing agent, to improve the contact between sample and modifier.…”
Section: Temperature Program and Modifiermentioning
“…Isso é um problema, pois técnicas que praticam a microanálise utilizam massas de amostra geralmente inferiores a 10 mg. Considerando a escassez de CRM para microanálise, alguns esforços vêm sendo direcionados no sentido de produzir materiais que atendam a essas exigências. Nesse sentido, avaliar a micro homogeneidade desses materiais torna-se uma etapa importante no processo de produção 21,38 . Atualmente existe disponível um material certificado de sedimento marinho (SRM 2703), produzido pelo NIST, que pode ser utilizado em microanálise, pois o mesmo apresenta homogeneidade garantida para massa de 0,7 mg.…”
Section: Figura 1 Número De Artigos Publicados Por Ano Referentes à unclassified
“…Segundo Pauwels et al 32 , a escolha da técnica deve ser feita considerando alguns requisitos importantes: não deve requerer pré-tratamento da amostra para evitar perdas dos analitos e contaminações; deve possibilitar análise precisa de pequenas massas de amostras, preferencialmente menor que 1 mg e, deve apresentar, preferencialmente, uma freqüência analítica alta. A SS GF AAS contempla todas essas características e, por isso, tem sido utilizada para avaliar a homogeneidade de diversos tipos de materiais 21,38 . A informação a respeito de homogeneidade de amostras foi inicialmente proposta por Igamells e Switzer 40 quando apresentaram a constante de amostragem (K S ) para estimar a imprecisão devido ao erro de amostragem, Equação 1…”
Section: Avaliação Da Micro Homogeneidadeunclassified
“…Uma outra forma de medir o branco analítico é realizar as medidas da plataforma de grafite vazia. O sinal de absorbância obtido refere-se à "massa zero" 21,38,45 . Nessa situação, o desvio padrão do branco analítico é aquele proveniente do "ruído" instrumental.…”
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