Estratégias analíticas para a determinação direta de alumínio, chumbo e cobre em amostras de bebidas por espectrometria de absorção atômica em forno de grafite

Abstract

The purpose of this study was to determine aluminum in beer and red wine samples, lead in beer samples and copper in ice-drinks (RTD) samples by eletrothermic atomization spectrometry, without samples preparation. Multivariate strategies (factorial and central composite design) were used for optimization of system. The use of permanent modifier showed a good way to minimize of the matrix effects. After optimization of pyrolysis temperature, in most studies, the atomization free of interference was obtained. This fact is proved by opportunity of calibration by standard solutions in water. Only for lead determination in beer was necessary a calibration using the matrix. Detection limits of 0.4, 0.3, 1.4 and 0.5 μg L-1, quantification limits of 1.3, 1.0, 4.8 and 1.6 μg L-1, characteristic mass of 16.0, 7.3, 16.3, 11.0 were found for aluminum in red wine, copper in ice drinks (RTD) and aluminum and lead in beers, respectively. The coefficient of variation was less than 5% for all matrices. The precision of the method was estimated by applying addition and recovery test where values were between 83-109%. Tests of validation such as detection and quantification limits, characteristic mass, and accuracy and precision were accordingly of literature. The results of present studies indicate that aluminum levels in wine are concern since the wine is a beverage consumed for some people.