In a study that investigated the release of lead in a number of beverages following contact with lead crystal vessels, the authors developed a method for determining the presence of this element in Coca Cola extracts. The extraction ability of Coca Cola was found to be similar to that of 4% acetic acid, as Coca Cola has an even lower pH. Analysis was performed by Zeeman corrected graphite furnace atomic absorption spectrometry. Optimum ashing and atomization temperatures were 850 and 1700 deg C respectively, and oxygen had to be used during the ashing stage to prevent carbon residues accumulating in the graphite tube. To improve the thermal stability a matrix modifier equivalent to 0.050mg NH4H2PO4 and 0.003mg Mg(NO3)2 was added by injection directly in the tube.
