Determinations of Sb and Mo in Cairoʹs dust using high-resolution continuum source graphite furnace atomic absorption spectrometry and direct solid sample analysis

The present work describes the determination of Sb and Mo in dust deposited on tree leaves using direct solid sample analysis. Nineteen air particulate samples were collected from different districts of Cairo and surrounding cities. Since some samples have been taken from places less exposed to the pollution factors, the present study allows the comparison of air quality between high and low polluted areas. High-resolution continuum source graphite furnace atomic absorption spectrometry has been investigated, using direct solid sample analysis. The optimum pyrolysis and atomization temperatures for Sb were found to be 800 °C and 1900 °C, and 1200 °C and 2650 °C, respectively for Mo. The limits of detection and quantification for both, Sb and Mo, were 15 μg g−1 and 50 ng g−1, respectively. The characteristic mass at was found to be m0 = 38 pg for Sb (217.582 nm) and m0 = 28 pg for Mo (313.259 nm). The results obtained for three certified reference materials of urban particulate matter confirmed the validity of the investigated method. The content of Sb varied between 213 ± 1.3 μg g−1 and 1117 ± 230 μg g−1 with an average of 667 ± 339 μg g−1. On the other hand, the Mo content varied from 113 ± 2.3 μg g−1 to 361 ± 51 μg g−1 and its average value equals 190 ± 62 μg g−1.