Comparison of three sequential extraction protocols for the fractionation of potentially toxic metals in coastal sediments
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Date
2011-01-17
Authors
Olayinka, K. O.
Oyeyiola, O. A.
Alo, B. I.
Journal Title
Journal ISSN
Volume Title
Publisher
Springer
Abstract
In the determination of the best sequen-
tial extraction procedures (SEP) for the speciation
of metals in sediment samples from the Lagos
lagoon system, three sequential extraction proce-
dures were compared for the fractionation of Cd,
Cr, Cu, Pb, and Zn. The SEP compared included
a modified Tessier’s procedure carried out in five
steps, while the two other procedures were the
three-step original Community Bureau of Refer-
ence (BCR) and the modified BCR techniques
(four steps). Quantification of the metal concen-
tration was achieved with a flame atomic absorp-
tion spectrophotometer. The results obtained
by the three methods were compared, and the
modified BCR and Tessier SEP were found to
extract more Cu, Cr, Pb, and Zn in the reducible
phase and therefore a decrease in the oxidizable
phase than the original BCR SEP. The most mo-
bile elements were found to be Cd, Pb, and Zn.
These are of environmental concern, as these po-
tentially toxic metals could be easily released into
the aquatic environment with consequent ingestion by aquatic organisms, thereby entering the
food chain. The mass balance (percent recovery)
was found to be between 85% and 115% in most
cases. Prior to the comparison, the analytical per-
formance of the laboratory was tested using a
secondary reference material, GLAURM, using
the three-step modified BCR procedure. The
results showed high reliability of the analytical
performance of the laboratory for all the metals
considered.
Description
Keywords
Research Subject Categories::NATURAL SCIENCES::Chemistry::Analytical chemistry::Separation methods , Speciation , Potentially toxic metals , Sediments , Lagos lagoon , Sequential extraction
Citation
Oyeyiola, A. O., Olayinka, K. O., & Alo, B. I. (2011). Comparison of three sequential extraction protocols for the fractionation of potentially toxic metals in coastal sediments. Environmental Monitoring and Assessment, 172(1-4), 319-327.