Abstract: In order to reduce the operation time and improve the extraction
efficiency, ultrasonic energy by means of ultrasonic bath was used to the
modified Tessier sequential extraction for speciation analysis of heavy metals
in soil. Extractable contents of Cu, Fe, Mn, Ni, Pb and Zn were measured by
atomic absorption spectroscopy (AAS). The merit of the ultrasonic extraction (UE)
applied to the modified Tessier method is not only that the operation time for
the first 4 fractions was reduced from ca.18 h to 8 h, comparing with
conventional extraction (CE), but also the extraction efficiency was higher. The
results for both of UE and CE were consistent. The extractable Cu, Ni and Zn in
the sample No.1 were mainly associated with the third fraction (Fe-Mn oxides
fraction), and fourth fraction (organic matter fraction) in the sample No.2. The
extractable Fe and Mn were all mainly associated with the third fraction, and
Pb the fourth fraction in both of the samples. The effects of concentration of
hydroxylamine chloride on the capability for the extraction of studied metals
were also studied.
Keywords: speciation analysis of heavy metal, sequential extraction, ultrasonic extraction, soil, atomic absorption spectrometry
