| Texto completo | |
| Autor(es): |
Porcionato, Rodrigo
;
Intima, Danielle Polidorio
;
Nomura, Cassiana Seimi
Número total de Autores: 3
|
| Tipo de documento: | Artigo Científico |
| Fonte: | BRAZILIAN JOURNAL OF ANALYTICAL CHEMISTRY; v. 1, n. 1, p. 5-pg., 2010-07-01. |
| Resumo | |
Solid sampling techniques have been recommended for analysis of biological and inorganic materials, in order to simplify sample preparation procedures. Besides the several advantages, the main limiting steps of these techniques are the use of appropriate materials for the analytical calibration curve and sample microhomogeneity. Although aqueous reference solutions can be used for calibration, certified reference materials (CRM) are necessary in most cases. However, most commercially available CRMs are homogeneous only for sample mass sizes higher than 100-500 mg, making their use as calibrating material not recommended for microanalysis. Additionally, it is not trivial to find CRMs certified for different concentrations of one specific analyte. The aim of this work is to propose the use of ceramics spiked with Cd and Pb reference solutions as a synthetic calibrating material for soil and sediment analysis, using solid sampling atomic absorption spectrometry (SS-GFAAS) as a tool for homogeneity investigation. After impregnation (0.5 to 50 mg kg(-1) for Cd and 10 to 1000 mg kg(-1) for Pb), each prepared standard had its homogeneity evaluated. The homogeneity factors ranged from 2.2 to 2.8 for Cd and from 5.0 to 13 for Pb. The analytical calibration curves were accomplished by increasing the mass of one calibrating standard and using four calibrating standards containing different concentration of Cd and Pb. Analysis of certified reference materials showed concentrations with no statistical differences at the 95 % confidence level, indicating that synthetic solid material based on spiking ceramics can be recommended for method calibration. (AU) | |
| Processo FAPESP: | 07/56504-6 - Avaliação de parâmetros e produção de materiais de referência de sangue, tecido muscular e vísceras de peixe para controle ecotoxicológico |
| Beneficiário: | Cassiana Seimi Nomura |
| Modalidade de apoio: | Auxílio à Pesquisa - Jovens Pesquisadores |