Determination of lead in aluminum and magnesium antacids using electrothermal atomic absorption spectrometry

This paper proposes a method for the determination of lead in aluminum and magnesium antacids employing electrothermal atomic absorption spectrometry (ET AAS). The pyrolysis and atomization temperatures established during the optimization step were 700 and 2200 degrees C, respectively, using phosphate as the chemical modifier. Under these conditions, a characteristic mass of 25 pg, and limits of detection and quantification of 0.40 and 1.35 mu g L-1, respectively were obtained. Some experiments demonstrated that the calibration can be performed employing the external calibration technique using aqueous standards. The precision expressed as relative standard deviation (RSD %) was 4.03% for an antacid sample with lead concentrations of 284.5 mu g L-1. The proposed method was applied for the determination of lead in five antacid samples acquired in Salvador City, Brazil. The lead content was varied from 87 to 943 mu g g(-1). The samples were also analyzed after complete dissolution by inductively coupled plasma mass spectrometry (ICP-MS). No statistical difference was observed between the results obtained by both of the procedures performed. (C) 2010 Elsevier B.V. All rights reserved.