Analytical strategies for determination of cadmium in Brazilian vinegar samples using ET AAS

This paper proposes two methods for determination of cadmium in vinegar employing electrothermal atomic absorption spectrometry. The optimization step was performed using two-level full factorial and Box-Behnken designs, being that a new multiple response function was established. Under experimental conditions of pyrolysis temperature of 640 °C and atomization temperature of 2000 °C, the direct method allows the analysis using the external calibration technique, with limit of quantification of 14 ng L(-1) and characteristic mass of 1.2 pg, having aluminium as chemical modifier. This method was applied in six samples of vinegar acquired from Salvador City, Brazil. The cadmium content varied from 20 to 890 ng L(-1). Other method was also proposed by digestion using nitric acid and hydrogen peroxide in reflux system employing cold finger, being cadmium determined by ETAAS. The results obtained with the complete digestion procedure were in agreement with those found by the direct method proposed herein.