Atomic absorption spectrometric determination of cadmium and lead in soil after total digestion

To establish the baseline levels of cadmium (Cd) and lead (Pb) in Pakistani soil, samples were collected from various ecological areas of the country. A total digestion procedure using an acid mixture of HF?HClO4 was investigated for heavy metal analysis of soil samples. Concentrations of these elements were measured using flame and graphite furnace atomic absorption spectrometry. Measured elemental contents of Cd and Pb varied from 0.411.18 and 22.4795.75 mu g/g with geometric mean 0.73 and 47.99 and geometric standard deviation concentrations of 1.36 and 1.65 mu g/g, respectively. Two certified reference materials (IAEA Soil-7 and IAEA-405 estuarine sediment) were introduced for the validation of analytical data. The estimated values were compared with other regions of the world and found lower than the world average values, Cd 27% and Pb 13%, and therefore considered comparatively safe and may not be a cause of concern for environmental pollution. Copyright (C) 2010 Curtin University of Technology and John Wiley & Sons, Ltd.