Enhancement of the atomic absorption signal by silicate at electrothermal atomic absorption spectrometry
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文摘
Effects of silicate on the atomic absorption of 26 elements were studied. It was found that the atomic absorption signals of aluminum, beryllium, chromium, gallium and molybdenum were enhanced in the presence of silicate by the factor of 3.13,16.1, 2.17, 23.1 and 1.25, respectively. The optimum silicate concentrations were 10–20 μg ml−1 Si(IV) for aluminum and beryllium, 80–120 μg ml−1 for gallium and 150–200 μg ml−1 for chromium and molybdenum. The detection limit and the slope of the calibration graph were comparable to those obtained by using known modifiers, i.e. magnesium nitrate for aluminum, beryllium and chromium and nickel nitrate for gallium. It was supposed that the silicate modifier may stabilize the pyrolysis step and facilitate the atomization. The use of the silicate modifier was applied for the determination of aluminum in a hot spring and a tap water sample.