Determina??o simultanea de As, Cd e Pb em amostras de água purificada para hemodiálise por espectrometria de absor??o at?mica com forno de grafite, após otimiza??o multivariada baseada no uso de planejamento experimental

摘要

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.