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Abstract
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This article describes the preparation of a nanocomposite
consisting of soluble eggshell membrane protein (SEP)
doped with reduced graphene oxide (rGO) as a sorbent for the
preconcentration of mercury(II) by solid phase extraction
(SPE). Incorporation of rGO was accomplished by dissolving
the eggshell membrane in a mixture of thioglycolic acid and
acetic acid, adding graphene oxide, and sonicating the solution.
The brown GO-SEP nanocomposite was then chemically
reduced to black rGO-SEP using hydrazine as the reducing
agent. The nanocomposite was found to be an efficient
nanosorbent for SPE of mercury(II). Following desorption of
Hg(II) ions from the sorbent with thiourea, Hg(II) was quantified
by anodic stripping voltammetry. Under optimized extraction
and electroanalytical conditions, the method has a
wide analytical range that is linear in the 0.5–80 ng mL−1
Hg(II) concentration range. The lower detection limit is
0.14 mg mL−1, the enrichment factor is 50, and the sorption
capacity is as high as 77 mg g−1.
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