Abstract
A sensitive and precise method was examined for the determination of molybdenum in environmental sediments by electrothermal atomic absorption spectrometry. The ground sample was digested with HF/HNO3/HClO4 or fused with sodium carbonate, then molybdenum was determined by standard addition method. Both use of a pyrolytic graphite-coated tube and addition of matrix modifier (Palladium (II) + magnesium nitrate) was effective for increasing sensitivity and precision. Constant absorbance was obtained in the charring temperature range of 1,400-1,600°C. Analytical results of molybdenum obtained by two proposed digestion methods agreed each other and were in good agreement with the certified or reference values for the environmental certified reference materials. Molybdenum concentrations in river, lake and marine sediments in Kanagawa prefecture were detected in the range of 0.545-2.66μg·g-1 (average 1.24μg·g-1). The detection limit of the proposed methods was 0.034μg·g-1 for 0.5g of sediment.
