Determination of Al, Cd, and Pb in Brazilian sugar cane spirit, cachaça, by ETAAS using matrix-matched calibration

Abstract

A method is described for the determination of aluminium, cadmium and lead in the Brazilian sugar cane spirit, cachaça, by Electrothermal Atomic Absorption Spectrometry (ETAAS) using matrix-matched calibration,i.e, calibration curves obtained at 405 (v/v) in ethanol-water media (the average alcohol content in cachaça). The methodology was applied to the determination of these three metals in 53 cachaça samples obtained from 53 different Jequitinhonha high valley producers, in the Minas Gerais state, Brazil. All metals were determined with or without permanent chemical modifiers such us Zr+Rh and Ir+Rh. The selection of pyrolysis and atomization temperatures was determined in the presence of the matrix. Best results were obtained without the use of chemical modifiers for Al and Cd. For Pb, the results without a modifier were similar to those obtained using Zr+Rh (500 and 250 microgrames) as the permanent modifier. For aluminum, without the use of a chemical modifier, the best pyrolysis and atomization temperatures were 1000 and 2500 degree centrigrates respectively ,with a characteristic mass (m sub o) of 9.0 pg (recommended 10 pg). it can therefore be assumed that cachaça itself in some way acts as modifier because it allows the use of higher temperatures for the three studied analytes.